RKI INSTRUMENTS 71-0626 GX-Force Portable Gas Detector Instruction Manual

The GX-Force is a high-quality instrument designed for gas
detection applications. It has been tested, inspected, and
calibrated to meet or exceed manufacturer’s specifications per ISO
9001 Quality System.

Operation

Start Up:

Turn on the device by pressing and holding the POWER MODE
button.

Wait for a brief warm-up period.
In normal operation mode, ensure you are in a fresh air
environment.

To turn off the device, press and hold the AIR button.

Maintenance

Replacing the Probe Filters:

Refer to the user manual for specific instructions on replacing
probe filters.

Replacing a Sensor:

Consult the user manual for detailed steps on replacing a
sensor.

Storage

When storing the GX-Force, follow the guidelines provided in the
user manual to ensure proper storage conditions are maintained.

General Parts List

Refer to the general parts list section in the user manual for
information on available replacement parts and accessories for the
GX-Force.

FAQ

Q: Where can I find the GX-Force manual?

A: You can scan the QR code provided on the device or visit the
manufacturer’s website at www.rkiinstruments.com for the
manual.

Q: How do I register my GX-Force product?

A: To register your product, visit
www.rkiinstruments.com/registration and follow the instructions
provided.

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GX-Force
Operator’s Manual
Part Number: 71-0626 Revision: D
Released: 3/4/25
RKI Instruments, Inc. www.rkiinstruments.com

WARNING
Read and understand this instruction manual before operating instrument. Improper use of the gas monitor could result in bodily harm or death. Maintenance of the gas monitor is essential for proper operation and correct readings. Bump test the instrument before each day’s use with a known concentration of each target gas. A bump test can be done in User Mode’s BUMP item or by applying gas in Measuring Mode. The instrument does not need to be calibrated unless it does not pass the User Mode bump test or does not respond appropriately, as defined by the user, in Measuring Mode. For more information about bump test and calibration requirements, see IEC 60079-29-2.
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GX-Force Quick Reference Guide

Turn On
Press & Hold

POWER MODE

GX-Force Quick Reference Guide

Past Due Bump/CAL

To Bump / CAL

POWER MODE

&RQ¿UP 8VH AIR

Normal Operation
After brief warm-up period
Fresh Air
Press & Hold
Turn Off
Press & Hold

AIR
POWER MODE

Scan QR code for GX-Force Manual
RKI Instruments, Inc. 33248 Central Ave, Union City, CA 94587 Phone 510-441-5656 · 800-754-5165 · www.rkiinstruments.com
230913/10000

Statement of Quality and Conformance
RKI Instruments, Inc. certifies that this instrument has been tested, inspected, and calibrated by a qualified technician and was found to meet or exceed the manufacturer’s specifications per ISO 9001 Quality System.
Register your Product here: www.rkiinstruments.com/registration
RKI Instruments, Inc. · 33248 Central Avenue, Union City, CA 94587 Phone: 510-441-5656 · 800-754-5165 · Fax: 510-441-5650 www.rkiinstruments.com
GX-Force Operator’s Manual · 3

Table of Contents
Chapter 1: Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 About the GX-Force . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 About this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Chapter 2: Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Instrument Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Case . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 LCD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Control Buttons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Alarm LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Buzzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Vibrator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Printed Circuit Boards (PCBs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Control Buttons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 USB-C Data/Charging Port and Protective Cover. . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Included Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Tapered Rubber Nozzle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Belt Clip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Optional Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 USB-C Data Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 AC Adapter Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 12 VDC Adapter Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Sample Hose & Probe. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 External Dilution Fitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
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Chapter 3: Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Start Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Turning On the GX-Force . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Performing a Demand Zero . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Turning Off the GX-Force . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Measuring Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Confirmation/Non-Compliance Indicator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Monitoring an Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Combustible Gas Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Oxygen-Enriched Atmospheres. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 H2-Compensated CO Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Interference Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Alarm Indications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Responding to Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Saving Snap Log Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Data Logging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Chapter 4: Display Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Tips for Using Display Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Mode Select (MODE.SEL). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 LED Flashlight (LIGHT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Peak Screen (PEAK). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 STEL Screen (STEL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 TWA Screen (TWA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Combustible Sensor Target Gas Conversion (LIST) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Turning the Pump Off (PUMP.OFF). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 Changing the User ID (USER ID) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 Changing the Station ID (STN ID) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 Last Successful Calibration Date (CAL DATA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 Last Successful Bump Test Date (BMP.DATA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 Viewing Snap Log Data (REC.DATA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 Date, Time, and Temperature Screen (TEMP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
GX-Force Operator’s Manual · 5

Viewing Alarm Settings Screen (ALARM – – P) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Chapter 5: User Mode and Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 Tips for Using User Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 Entering User Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 Performing a Bump Test (BUMP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 Performing a Calibration (GAS CAL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 Setting Calibration Parameters (CAL SET) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 Setting Bump Test Parameters (BUMP.SET) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 Alarm Settings (ALARM – – P) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 Updating the Lunch Break Setting (LUNCH) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 Setting the Confirmation Beep and Non-Compliance Indicator (BEEP) . . . . . . . . . . . . . . . . 91 Updating the Backlight Time (BL TIME). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Turning the Key Tone On/Off (KEY.TONE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Display Mode Items (DISP.SET) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 Zero Suppression (ZERO.SUP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 Zero Follower (ZERO.FLW) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 Setting the Date/Time (DATE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 Turning the Password On/Off (PASS – – W). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 Viewing the ROM/SUM (ROM/SUM). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 Entering Measuring Mode (START) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
Chapter 6: Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 Instrument Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 Recharging the Battery Pack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 Replacing the Sensor Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Combustible Gas Sensor Filter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 Dual CO/H2S Sensor Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 CO-Only/H2-Compensated CO Sensor Filter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 H2S-Only Sensor Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 Replacing the Inlet Filters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
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Replacing the Probe Filters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 Replacing a Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Chapter 7: Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
Chapter 8: General Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Appendix A: Maintenance Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 Tips for Using Maintenance Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 Entering Maintenance Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 Performing a Calibration (GAS CAL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 Performing a Gas Test (GAS TEST). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 Sensor/Battery Replacement Date (SEN.DATE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 Performing a Bump Test (BUMP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 Setting Alarms to Latching or Self-Resetting (LATCH) . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 Turning the Alarm Silence Function On/Off (ALM.SNC) . . . . . . . . . . . . . . . . . . . . . . . . . . 119 Turning the Demand Zero Function On/Off (D.ZERO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 Turning the Auto Zero Function On/Off (A.ZERO). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 Turning the ID Display Function On/Off (ID DISP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 Turning the Zero Suppression On/Off (ZERO.SUP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 Turning the Zero Follower On/Off (ZERO.FLW) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 User Mode Zero Suppression (ZSUP.DISP). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 User Mode Zero Follower (ZFLW.DISP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 Turning the Pump Off Display On/Off (POFF.DSP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 Turning Mode Select On/Off (L.C. MODE). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 Setting the Date/Time (DATE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 Turning the Password On/Off (PASS – – W). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 Viewing the ROM/SUM (ROM/SUM). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 Performing a Flow Adjustment (FLOW.ADJ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 Performing a Default (M.DEFAULT). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 Entering Measuring Mode (START) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Appendix B: Gas Select Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
GX-Force Operator’s Manual · 7

Tips for Using Gas Select Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 Entering Gas Select Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 Changing the Gas Combination (GAS.COMB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 Saving the Alarm Points (SAVE-AP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132 Turning Calibration Max Span On/Off (MAX.SPAN) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 Stealth and Vibrator Settings (STEALTH) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 LEL Definition (CHG LEL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 Exiting Gas Select Mode (START). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
Appendix C: Leak Check Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 Start Up, Leak Check Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138 Leak Check Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 Snap Log Mode, Leak Check Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143 Display Mode, Leak Check Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 Adjusting Leak Check Settings (GX-Force Setup Program) . . . . . . . . . . . . . . . . . . . . . . . . 150
Appendix D: Interference Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
ESR-A13i-H2S, H2S Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 ESR-A13P-CO, CO Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 ESR-A1CP-COH, H2-Compensated CO Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 ESR-A1DP-COHS, CO Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 ESR-A1DP-COHS, H2S Detection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 WARNING: Understand manual before operating. Substitution of components may impair
intrinsic safety. To prevent ignition of a hazardous atmosphere, batteries must only be changed or charged in an area known to be nonhazardous.
8 · GX-Force Operator’s Manual

Chapter 1: Introduction

Overview
This chapter briefly describes the GX-Force portable gas monitor. This chapter also describes the GX-Force Operator’s Manual (this document). Table 1 and Table 2 at the end of this chapter list the GX-Force’s sensor and instrument specifications.
About the GX-Force
Using an advanced detection system consisting of up to three gas sensors, the GX-Force personal four-gas monitor detects the presence of combustible gas, oxygen (O2), carbon monoxide (CO), and hydrogen sulfide (H2S) simultaneously. The GX-Force’s compact size and easy-to-use design make it ideally suited for a wide range of applications, including sewage treatment plants, utility manholes, tunnels, hazardous waste sites, power stations, petrochemical refineries, mines, paper mills, drilling rigs, and fire fighting stations. The GX-Force offers a full range of features, including:
· Simultaneous monitoring of one to four gases · Liquid crystal display (LCD) for complete and understandable information at a glance · Ultrabright alarm LEDs · Distinctive audible/vibrating alarms for dangerous gas conditions and audible alarms for
unit malfunction · Microprocessor control for reliability, ease of use, and advanced capabilities · Choice of two operating modes:
· Normal Mode for typical confined spaces or area monitoring (standard factory setting) · Leak Check Mode for locating leaks in valves and piping (see Appendix C: Leak
Check Mode) · Data logging functions · Alarm trend data · STEL, TWA, and over range alarms · Peak readings · Built-in time function · Lunch break feature · QPS “C/US” classified as intrinsically safe
WARNING: The Model GX-Force detects oxygen deficiency, elevated levels of oxygen, combustible gases, carbon monoxide, and hydrogen sulfide, all of which can be dangerous or life threatening. When using the GX-Force, you must follow the instructions and warnings in this manual to assure proper and safe operation of the unit and to minimize the risk of personal injury. Be sure to maintain and periodically calibrate the GX-Force as described in this manual.

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Chapter 1: Introduction · 9

Specifications

Table 1: Standard Sensor Specifications/Alarm Points

Combustible Gas,
Methane (CH4) Calibration Standard*

Oxygen (O2)

Hydrogen Sulfide (H2S)

Carbon Monoxide (CO)

Detection Range

0 – 100% LEL

0 – 40% volume 0 – 200.0 ppm

0 – 2,000 ppm

Lowest

n/a

Detectable

Limit (LDL)

n/a

0.5 ppm

3 ppm

Reading Increment

1% LEL

0.1% volume

0.1 ppm

1 ppm

Warning Setpoint

10% LEL

19.5% volume, decreasing

5.0 ppm

25 ppm

Alarm Setpoint

25% LEL

18.0% volume, decreasing

30.0 ppm

50 ppm

Alarm H Setpoint

50% LEL

23.5% volume, increasing

100.0 ppm

1200 ppm

STEL

n/a

5.0 ppm

200 ppm

Setpoint

TWA Setpoint

n/a

1.0 ppm

25 ppm

Indication Accuracy**

· Continuous environment (-20°C to 50°C): ± 5% of reading or ± 2% LEL (whichever is greater)
· Temporary environment (-40°C to -21°C and 51°C to 60°C): ± 10% LEL

· 0 – 25.0%: ± 0.5% O2
· 25.1 – 40.0%: ± 3.0% O2

· 0 – 100 ppm: ± 5% of reading or ± 2 ppm H2S (whichever is greater)
· 101 – 200 ppm: ± 20% of reading

· 0 – 500 ppm: ± 5% of reading or ± 5 ppm CO (whichever is greater)
· 501 – 2000 ppm: ± 20% of reading

* The GX-Force is also available set up for general hydrocarbons and calibrated to a combustible gas other than methane, such as isobutane. Consult RKI Instruments, Inc. for further information.
** Indication accuracy specifications are measured at constant conditions.

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Sampling Method Response Time Display Environmental Conditions
Operating Temperature & Humidity
Safety/ Regulatory

Table 2: GX-Force Specifications
Sample Draw
T90 within 30 seconds
Graphics LCD Display
· Operating pressure: 80 – 120 kPa (80 – 110 kPa for explosion-proof classification) · IP 67
Continuous environment: -20°C to 50°C/Below 90% RH Temporary environment (up to 15 minutes): -20°C to 60°C/Below 95% RH Ambient temperature range (for charging): 10°C to 40°C NOTE: The H2-compensated CO sensor may not effectively compensate for higher levels of H2 if exposed to temperatures above 40°C for longer than 15 minutes. Under these conditions, it can appear to the instrument that the H2 concentration has exceeded 2000 ppm, the max concentration that can be compensated for, resulting in a CO reading higher than the actual CO level.
· ATEX: Certificate Number: DEKRA 24ATEX0018X II1G Ex da ia IIC T4 Ga (with NCR-6309) II1G Ex ia IIC T4 Ga (without NCR-6309)
· IECEx: Certificate Number: IECEx DEK 24.0016X Ex da ia IIC T4 Ga (with NCR-6309) Ex ia IIC T4 Ga (without NCR-6309)

· QPS classified, “C/US”, as Intrinsically Safe. Class I Division 1 Groups A, B, C, D T4. Class I, Zones 0, A/Ex da ia IIC T4 Ga (with NCR-6309) Class I, Zones 0, A/Ex ia IIC T4 Ga (without NCR-6309)

Power Supply Lithium ion battery pack (3.6V, 300 mA)

Continuous Operating Hours @ 25 °C

· In Normal Mode: 30 hours (non-alarm operation) · In Leak Check Mode: 20 hours (non-alarm operation)

Input: 100 – 240 VAC, 50/60 Hz, 0.6 A
Battery Charger Output: 5.0 VDC, 3 A max
Estimated Charge Time: 8 hours

Case

High-impact Plastic, RF-Shielded, Dust and Water Proof (IP 67)

Included Accessories

· Belt clip · Tapered rubber nozzle

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Chapter 1: Introduction · 11

Table 2: GX-Force Specifications

Optional Accessories

· USB Type-C data cable · AC adapter · 12 VDC adapter · Hose and 8-inch probe · Hose/Probes of various lengths, see “Chapter 8: General Parts List” on page 109 · Dilution Fitting (1:1) · Data Logger Management Program

Dimensions and Approximately 173(H) x 64(W) x 47(D) mm (6.8″ H x 2.5″ W x 1.9″ D)

Weight

Approximately 300 g (10.6 oz.)

About this Manual
The GX-Force Operator’s Manual uses the following conventions for notes, cautions, and warnings.
NOTE: Describes additional or critical information.

CAUTION: Describes potential damage to equipment.

WARNING: Describes potential danger that can result in injury or death.

12 · Chapter 1: Introduction

GX-Force Operator’s Manual

Chapter 2: Description

Overview
This chapter describes the GX-Force instrument and its accessories.

Instrument Description

Alarm LEDs

Filter Casing Flashlight

Gas Inlet

Gas Outlet

LCD Display

AIR Button

POWER MODE Button

Buzzer Opening

Wrist Strap Holes
Charging LED FRONT VIEW

BACK VIEW

Figure 1: Component Location

Case
The GX-Force’s sturdy, high-impact plastic case is radio frequency (RF) resistant and suitable for use in many environmental conditions, indoors and out. The case is dust-proof and waterresistant. A clear plastic window on the front of the case allows for LCD viewing.
Four screws in each corner of the back case allow access to the sensors and filters. Three threaded inserts on the back of the case allow for installation of a belt clip.

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Chapter 2: Description · 13

LCD
The digital LCD (liquid crystal display) simultaneously shows the gas reading for all installed sensors. The LCD also shows information for each of the GX-Force’s operating modes.
WARNING: A thin protective film covers the display to prevent scratches during shipping. Remove this film before use. Leaving the film installed voids the intrinsically safe certification.

Control Buttons
Two control buttons, AIR and POWER MODE, are located below the LCD.
Table 3: GX-Force Control Button Functions

Button

Functions

AIR

· turns on LCD backlight

· resets alarm condition if LATCH is set to ON in Maintenance Mode

· enters User Mode, Maintenance Mode, and Gas Select Mode when used with POWER MODE button

· activates the demand zero function (adjusts the GX-Force’s fresh air reading)

· changes the value of a parameter available for adjustment

· scrolls through parameter options

POWER MODE

· turns the GX-Force on and off · turns on LCD backlight · enters and scrolls through Display Mode · enters instructions into the GX-Force’s microprocessor · resets alarm condition if LATCH is set to ON in Maintenance Mode · enters User Mode, Maintenance Mode, and Gas Select Mode when
used with AIR button

Flashlight LED
A white LED is visible through a round, raised, frosted lens in the top of the case. This LED can be used to provide extra light, if necessary. The flashlight can be activated in the Display Mode. See page 47 for activating and deactivating the flashlight LED.
Alarm LEDs
The six alarm LEDs around the edge of the case alert you to gas, low battery, and failure alarms.

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Charging Indicator LED
One LED located near the bottom of the instrument lights up green when a power cable is plugged into the instrument’s charging/data port. The LED changes to orange as charging begins. When charging is complete, the LED turns green until the instrument is disconnected from power.
Buzzer
One solid-state electronic buzzer is located inside the case. Sound exits the case through a hole in the middle front of the case. The buzzer sounds for gas alarms, malfunctions, low battery voltage, and as an indicator during use of the GX-Force’s many display and adjustment options.
Vibrator
A vibrating motor inside the GX-Force case vibrates for gas alarms, unit malfunctions, and as an indicator during normal use of the various modes of the GX-Force.
NOTE: If STEALTH is set to ON, the vibrator only functions when VIB in the STEALTH Gas Select Mode item is set to ON. See “Stealth and Vibrator Settings (STEALTH)” on page 133.
Printed Circuit Boards (PCBs)
The GX-Force’s printed circuit boards analyze, record, control, store, and display the information collected. The circuit boards are located inside the case. They are not user serviceable.
Pump
A diaphragm pump inside the GX-Force draws the sample to the sensors. It can draw sample from as far as 100 feet from the GX-Force. The pump is not user serviceable.
CAUTION: Sample hose lengths of more than 100 feet are not recommended for the GX-Force because of flow rate reduction.
Flow Chamber
The flow chamber is on the back of the GX-Force and is held in place by four Phillips screws. The flow chamber seals to the rubber sensor gasket which seals to the sensor faces inside the GXForce and routes flow from the pump to the sensors and to the exhaust port (on the back of the GX-Force case).
Sensors
The GX-Force uses three sensors to monitor combustible gas, oxygen (O2), carbon monoxide (CO), and hydrogen sulfide (H2S) simultaneously. The sensors are located inside the GX-Force and are held in their sockets by the sensor retainer and back case. The sensors use different detection principles, described in the following sections.

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Chapter 2: Description · 15

Combustible Gas Sensor
The combustible gas sensor (NCR-6309) detects combustible gas in the %LEL range using 2 catalytic elements: a standard element and a poison-resistant element that is resistant to sensor poisons like silicone. The element’s electrical resistance changes based on the reaction of gas with oxygen. The change in resistance affects the current flowing through the element. The GXForce’s circuitry amplifies the current, converts the current to a gas concentration, and displays the concentration on the LCD.
The standard calibration for the combustible gas sensor is to methane, but the sensor will still detect and respond to a variety of combustible gases.
O2/CO/H2S Sensors
The O2, CO, and H2S sensors are electrochemical cells that consist of two precious metal electrodes in a dilute acid electrolyte. A gas permeable membrane covers the sensor face and allows gas to diffuse into the electrolyte. The gas reacts in the sensor and produces a current proportional to the concentration of the target gas. The GX-Force’s circuitry amplifies the current, converts the current to a gas concentration, and displays the concentration on the LCD.
There are 4 different types of CO and H2S sensors available: · CO-only (ESR-A13P-CO): A single electrochemical cell that detects CO. Instruments with this sensor cannot detect H2S. · H2-compensated CO (ESR-A1CP-CO-H): A single electrochemical cell that detects CO. This sensor does not respond to or responds minimally to hydrogen (displays H2 RICH once H2 concentration reaches 2000 ppm). Instruments with this sensor cannot detect H2S. · H2S only (ESR-A13i-H2S): A single electrochemical cell that detects H2S. Instruments with this sensor cannot detect CO.
· CO/H2S (ESR-A1DR-COHS): A combination electrochemical cell that detects both CO and H2S.
Dummy Sensors
A dummy sensor is installed in any units that have less than 3 sensors. Dummy sensors are factory installed. The flat side of the dummy sensor faces away from the GX-Force and the hollow side faces toward the GX-Force.
Filters
Combustible Gas Sensor H2S Removal Filter Disk (Dark Red)
An H2S removal filter disk is placed into a recess in the filter gasket over the combustible gas sensor. The filter disk prolongs the life of the combustible gas sensor by preventing H2S in the ambient air from reaching the sensor. The H2S filter disk is dark red in color and although it may darken over time, its color is not indicative of remaining filter life.
The H2S filter disk needs replacing once it’s been exposed to 33 ppm hours of H2S. This means the filter needs replacing after 80 minutes of exposure to 25 ppm H2S which equates to 40, 2minute calibrations with a cylinder containing 25 ppm H2S. If H2S exists in the monitoring environment, the H2S filter disk will have to be replaced more frequently.

16 · Chapter 2: Description

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CO/H2S Sensor Dual Filter (Black and White)
A dual filter is placed into a recess in the filter gasket over the dual CO/H2S sensor. The black half is a charcoal filter for the CO sensor. The white half is a humidity filter for the H2S sensor. Replace the filter if you notice the following:
· Unexplained CO readings
· For users with a 1 ppm H2S alarm setpoint, the filter should be replaced every 6 months, if you notice a drift on the H2S zero reading, unexplained H2S readings, or if the filter appears dirty (whichever is sooner).
CO-Only and H2-Compensated CO Sensor Charcoal Filter (Black)
A black charcoal filter is placed into a recess in the filter gasket over the CO sensor. The charcoal filter disk scrubs H2S and certain hydrocarbons out of the sample to avoid false CO readings. If false or elevated CO readings are noticed, especially in the presence of H2S, change the charcoal filter.
H2S Sensor Humidity Filter (White)
A white humidity filter covers the H2S sensor. The filter absorbs humidity in the sampling environment to prevent unstable readings around 0 ppm H2S. For users with a 1 ppm H2S alarm setpoint, the filter should be replaced every 6 months, if you notice a drift on the zero reading, or if the filter appears dirty (whichever is sooner). For users with a 2 ppm or higher H2S setpoint, the filter does not necessarily need to be replaced.
Inlet Filter Holder
The filter holder is a clear plastic dome-shaped piece on the top of the case. A male quick connect fitting is located on the inlet filter holder. This is the GX-Force’s inlet fitting. The filter holder may be removed by turning it counterclockwise and pulling it away from the case. One flat membrane disk hydrophobic filter, a wire mesh disk, and a rubber filter retaining gasket are held in place by the filter holder and are located in the bottom of the case chamber where the filter holder is installed.
Exhaust
Sample gas flows from the sensors to the exhaust port on the back of the GX-Force.
USB-C Data/Charging Port and Protective Cover
A USB Type-C port is located on the bottom of the GX-Force, protected by a rubber cover. Pry off this cover when plugging in a USB Type-C cable (for charging or data transfer). A USB Type-C adapter cable can be connected to a computer’s USB port to transfer data to the GX-Force Data Logger Management Program.
See the GX-Force Data Logger Management Program Operator’s Manual for downloading instructions.

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Chapter 2: Description · 17

Battery Pack
A lithium ion (Li-ion) battery pack powers the GX-Force. At 25°C, the battery lasts at least 30 hours in Normal Mode and at least 20 hours in Leak Check Mode. The battery icon in the lower left corner of the LCD shows remaining battery life. A low battery warning activates when the GX-Force detects a low battery voltage. The GX-Force sounds a dead battery alarm when battery voltage is too low for Measuring Mode. The battery pack can be recharged using an AC or DC charger.
NOTE: Use of batteries or battery chargers not specified by RKI Instruments, Inc. will compromise the QPS classification and may void the warranty. See “Recharging the Lithium Ion Battery Pack” on page 99.
WARNING: To prevent ignition of a hazardous atmosphere, batteries must only be charged in an area known to be nonhazardous.
AVERTISSEMENT: Pour éviter l’inflammation d’une atmosphère dangereuse, les batteries ne doivent être chargées que dans une zone connue pour être non dangereuse.
Included Accessories
Included accessories consist of the tapered rubber nozzle and belt clip.
Tapered Rubber Nozzle
A cone-shaped 4-inch long rubber nozzle is included with the GX-Force as standard. It can be installed on the inlet fitting by pushing the larger end over it. The smaller end can be inserted through a hole in a wall or some other access to an enclosed area to sample the environment.
Belt Clip
The belt clip can be mounted to the back of the case using 3 Phillips head screws. The belt clip allows the GX-Force to be securely attached to clothing or a belt.

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GX-Force Operator’s Manual

Optional Accessories
Optional accessories consist of a USB-C data cable, an AC adapter cable, a 12 VDC adapter cable, a sample hose with an 8-inch probe, and an external dilution fitting.
USB-C Data Cable
The USB cable can be ordered for connecting the GX-Force to a computer when using the GXForce Data Logger Management Program. NOTE: The USB-C data cable should not be used to charge the instrument. Its intended function
is to communicate with the GX-Force Data Logger Management Program.
AC Adapter Cable
The charging cable is a 4 foot cable with an AC adapter on one end and a USB Type-C charging plug that connects to the GX-Force on the other end.
Figure 2: AC Adapter (USB Type-C)
12 VDC Adapter Cable
A 12 VDC adapter can be ordered for charging cable is equipped with a vehicle DC plug on one side and a USB-C plug on the other to plug into the GX-Force’s USB-C charging and data port.

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Chapter 2: Description · 19

Sample Hose & Probe
A sample hose and probe can be ordered with the GX-Force. When desired, the rubber nozzle may be removed and the sample hose and 8-inch probe may be connected to the inlet fitting. Sample hose lengths are available from 3 feet to 100 feet (see “Chapter 8: General Parts List” on page 109). The quick connect end of the sample hose connects to the inlet fitting of the GX-Force and the probe screws onto the end of the hose with the threaded fitting. CAUTION: Sample hose lengths of more than 100 feet are not recommended for the GX-Force
because of flow rate reduction.
Figure 3: Sample Hose and Probe
External Dilution Fitting
A 1:1 external dilution fitting is available for the GX-Force. It is designed to mate with the inlet fitting and accept a sample hose and probe. The fitting is made with brass and nickel plated brass and is appropriate for use with the four standard gases. The fitting is normally used when it is necessary to introduce air into a sample that has no oxygen or a very low level of oxygen, such as a nitrogen-purged sample. It can also be used when one of the target gas levels in the sample area will likely be present in a concentration above the detection range for that gas. Since the fitting partially consists of unplated brass, it is not appropriate for detection of elevated levels of H2S.
Figure 4: 1:1 Dilution Fitting

20 · Chapter 2: Description

GX-Force Operator’s Manual

Chapter 3: Operation

Overview
This chapter explains how to use the GX-Force to perform confined space entry monitoring or general area monitoring in Measuring Mode.

Start Up
This section explains how to start up the GX-Force, get it ready for operation, and turn it off.
WARNING: A thin protective film covers the display to prevent scratches during shipping. Remove this film before use. Leaving the film installed voids the intrinsically safe certification.

Turning On the GX-Force

1. Connect a tapered rubber nozzle or sample hose and probe to the GX-Force’s quick-connect inlet fitting.

2. Press and briefly hold down POWER MODE. Confirm that the LCD turns on, the LEDs flash, the buzzer sounds, and the motor vibrates before continuing with operation. Release the POWER MODE button after the instrument beeps once.

3. If L.C. MODE is set to ON (factory setting, see page 122) and GAS.COMB in Gas Select Mode is set to methane (CH4) or isobutane (i-C4H10), the Mode Select screen appears. Press AIR to scroll between Normal Mode and Leak Check Mode.
Press POWER MODE to confirm. If no mode is selected after 20 seconds, the unit automatically starts up in Normal Mode.

7:49
SELECt

7:49
AIR
SELECt

NORMAL

LEAK

4. If LUNCH is set to ON (factory setting if OFF, see page 90), the Lunch Break Screen appears. The unit counts down from 5 seconds.
7:49
5
SEC
RESUME

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Chapter 3: Operation · 21

a. Continue Accumulating: To continue accumulating peak and time-weighted average (TWA) readings from the last time the GX-Force was used, press POWER MODE or allow the countdown to reach 0. The short-term exposure limit (STEL) reading is reset each time the GX-Force is turned on.
b. Reset Accumulation: To reset the accumulation of peak and time-weighted average (TWA) readings, press AIR before the countdown reaches 0.
5. If CAL.RMDR is set to ON (factory setting, see page 81) and a calibration is due, the screen that appears next depends on the CAL.EXPD setting in User Mode (see page 82). The three possible screens are described below. If a calibration is not due, the instrument shows how many days are left until a calibration is due.

CAL.EXPD set to CONFIRM (factory setting)

CAL.EXPD set to CANT USE

CAL.EXPD set to NONE

LCD
7:49
CAL
CAL — LMT

7:49
FAIL
CAL — LMT

7:49
0d
NEXT CAL

Sound Buzzer sounds double pulsing Buzzer sounds double pulsing None

tone

Action

· Option A, Perform calibration: Press POWER MODE to perform a calibration. The instrument takes you straight to the AUTO.CAL CYL A screen in User Mode’s GAS CALAUTO.CAL item. If PASS–W is set to ON, you must enter a password. See page 70 for calibration instructions. If the calibration is successful, the screen above will not appear again until the unit is due for calibration. If the calibration is not successful, the screen above will again appear in the startup sequence.
· Option B, Bypass message: To continue without performing a calibration, press AIR.

· The GX-Force cannot be used until a successful calibration is performed. Press POWER MODE to perform a calibration. The instrument takes you straight to the AUTO.CAL CYL A screen in User Mode’s GAS CALAUTO.CAL item. If PASS–W is set to ON, you must enter a password. If you don’t press POWER MODE, the instrument automatically goes to the AUTO.CAL CYL A screen after 6 seconds. See page 70 for calibration instructions.
· If the calibration is successful, the screen above will not appear again until the unit is due for calibration. If the calibration is not successful, the screen above will again appear in the startup sequence.

· Option A, Perform calibration: To perform a calibration, press POWER MODE. The instrument takes you straight to the AUTO.CAL CYL A screen in User Mode’s GAS CALAUTO.CAL item. If PASS–W is set to ON, you must enter a password.
· Option B, Bypass message: To continue without performing a calibration, wait a few seconds for the instrument to continue with its startup sequence.

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6. If BMP.RMDR is set to ON (factory setting is OFF, see page 86) and a bump test is due, the screen that appears next depends on how BMP.EXPD is set in User Mode (see page 87). The three possible screens are described below. If a bump test is not due, the instrument shows how many days are left until a bump test is due.

BMP.EXPD set to CONFIRM (factory setting)

BMP.EXPD set to CANT USE

BMP.EXPD set to NONE

LCD

7:49

CAL
BMP.LMT

FAIL
BMP.LMT

0d
NEXT.BMP

Sound Action

Buzzer sounds double pulsing Buzzer sounds double pulsing None

tone

· Option A, Perform bump test: Press POWER MODE to perform a bump test. The instrument takes you straight to the BUMP CYL A screen in User Mode’s BUMP item. If PASS–W is set to ON, you must enter a password. See page 64 for bump test instructions.
If the bump test is successful, the screen above will not appear again until the unit is due for bump testing. If the bump test is not successful, the screen above will again appear in the startup sequence.
· Option B, Bypass message: To continue without performing a bump test, press AIR.

· The GX-Force cannot be used until a successful bump test has been performed. Press POWER MODE to perform a bump test. The instrument takes you straight to the BUMP CYL A screen in User Mode’s BUMP item.
If PASS–W is set to ON, you must enter a password. If you don’t press POWER MODE, the instrument automatically goes to the BUMP CYL A screen after 6 seconds. See page 64 for bump test instructions.
· If the bump test is successful, the screen above will not appear again until the unit is due for bump testing. If the bump test is not successful, the screen above will again appear in the startup sequence.

· Option A, Perform bump test: To perform a bump test, press POWER MODE. The instrument takes you straight to the BUMP CYL A screen in User Mode’s BUMP item. If PASS–W is set to ON, you must enter a password.
· Option B, Bypass message: To continue without performing a bump test, wait a few seconds for the instrument to continue with its startup sequence.

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Chapter 3: Operation · 23

7. The Date/Time Screen appears for a few seconds.
7:49
22 – 12.20 7:49

8. The Battery Voltage Screen appears for a few seconds. An “AL-L” at the bottom of the screen indicates that the alarms are set to latching. An “ALA” at the bottom of the screen indicates that the alarms are set to auto reset. See page 118 for changing the LATCH setting in Maintenance Mode.
7:49
bAtt
4.1
AL – L V

9. The combustible gas sensor contains 2 separate sensors: a standard catalytic sensor and a backup, poison-resistant sensor that is resistant to sensor poisons like silicone. An HC Gas List alarm indicates that the standard sensor has a reduced output, possibly due to one or more sensor poisons in the environment, and that the poison-resistant sensor is being used to provide gas readings. The poison-resistant sensor has a limited list of detectable gases. See Table 10 on page 49 for which gases can and cannot be detected during an HC Gas List condition.
The following screen appears, the LEDs flash, and the instrument beeps.

7:49

rEAd GAS

LISt

MANUAL

Press POWER MODE to confirm the HC Gas List screen and continue to the Gas Name Screen. If POWER MODE is not pressed after 5 seconds, the GX-Force will automatically proceed to the next screen.

NOTE: If your application requires detection of a gas still detectable after an HC Gas List condition (like methane or isobutane), there is no need to replace the combustible gas sensor.

However, if your application requires detection of a gas not detectable after an HC Gas List condition (like methanol or ethanol), you must replace the combustible gas sensor as soon as possible.

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10. The following screens display for 3 seconds each: the Gas Name Screen, the Full Scale Screen, the Warning Setpoint Screen, the Alarm Setpoint Screen, the Alarm H Setpoint Screen, the STEL Alarm Screen, and TWA Alarm Screen.
NOTE: If the combustible gas is set to something other than CH4 or H2 in Gas Select Mode, the combustible channel is displayed as “HC” and the gas formula for the combustible gas sensor’s target gas appears during startup.

7:49

%LEL

CH4 O2

ppm
CO

ppm
H2S

7:49

CH4 %LEL
100

40.0

ppm

2000

H2S

ppm

200.0

F. S.

7:49

CH4 %LEL
10

19.5

ppm

H2S

ppm

5.0

WARNING

7:49

CH4 %LEL
25

18.0

ppm

H2S

ppm

30.0

ALARM

7:49

CH4 %LEL
50

23.5

ppm

1200

H2S

ppm

100.0

ALARM H

7:49

ppm

200

H2S

ppm

5.0

STEL

7:49

ppm

H2S

ppm

1.0

TWA

GX-Force Operator’s Manual

Chapter 3: Operation · 25

11. If ID DISP is set to ON (factory setting is OFF, see page 120), the User ID Screen appears for a few seconds, followed by the Station ID Screen.

7:49

USEr Id

Stn Id

U_ID_001

S_ID_001

12. If the GX-Force experiences a sensor failure during start up, the display shows which sensor failed and the buzzer sounds a double pulsing tone once per second. In the example below, the combustible gas sensor failed.
7:49
CH4 %LEL
FAIL

SENSOR
Press POWER MODE to acknowledge the failure and continue. “- – – -” replaces the failed sensor’s gas reading. Replace the failed sensor as soon as possible.
13. If A.ZERO is set to ON (factory setting is OFF, see page 119), the instrument prompts you to do an auto zero. An auto zero operation sets the combustible gas, H2S, and CO channels to zero and the O2 channel to 20.9%.

7:49

A.ZERO

YES / MODE

NO / AIR

WARNING: Make sure that the instrument is in a known fresh air environment (an environment free of combustible or toxic gases and of normal oxygen content, 20.9%) before performing an auto zero operation. If you perform an auto zero operation in an area with gases present, the adjustment will not be accurate.
You must press POWER MODE to perform an auto zero function. If you do not press any key after 15 seconds, the instrument enters Measuring Mode without performing an auto zero.

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14. At the end of the 45 second warmup, the GX-Force begins monitoring for gas in Measuring Mode. The Measuring Mode Screen displays the current gas reading for each target gas.

7:49

CH4 %LEL
0

20.9

ppm

H2S

ppm

0.0

Performing a Demand Zero
Perform a demand zero before using the GX-Force. This sets the combustible gas, H2S, and CO channels to zero and the O2 channel to 20.9%. 1. Find a fresh-air environment. This is an environment free of toxic or combustible gases and of
normal oxygen content (20.9%).
2. Turn on the unit as described above in “Turning On the GX-Force” on page 21.
3. Press and hold AIR. The LCD prompts you to continue holding AIR and the buzzer pulses while you hold the button (if KEY.TONE is set to ON in User Mode).
4. Continue to hold AIR until the LCD prompts you to release it. The GX-Force sets the fresh air reading for all channels. Start up is complete and the unit is now ready for monitoring.
5. If PASS–W is turned ON (factory setting is OFF), a user-set password is required to perform a demand zero. When the password screen appears, adjust each digit with the AIR button and press the POWER MODE button to move on to the next digit. Once the password is entered, the instrument performs the demand zero.
7:49
0 0 0 0
PASS – – W

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Chapter 3: Operation · 27

Turning Off the GX-Force
1. To turn off the GX-Force, wait for all readings to return to zero (20.9% for oxygen) and press and hold POWER MODE. NOTE: If any channel is displaying a non-fresh air reading during shutdown, the instrument will perform a purge to clear the internal pump system. A 30second countdown will be displayed.
7:49
29
PURGE
2. “TURN OFF” appears on the display and the buzzer pulses three times (if KEY.TONE is set to ON in User Mode).
3. Release the button when “TURN OFF” disappears from the display. 4. If PASS–W is turned ON (factory setting is OFF), a user-set password is required to perform
a demand zero. When the password screen appears, adjust each digit with the AIR button and press the POWER MODE button to move on to the next digit. Once the password is entered, the instrument performs the demand zero.
7:49
0 0 0 0
PASS – – W
5. If you plan to leave the instrument off for an extended period of time, see page 108.

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Measuring Mode Operation

When the GX-Force completes its startup sequence, it is in Measuring Mode. In Measuring Mode, the GX-Force continuously monitors the sampled atmosphere and displays the target gas concentrations. The GX-Force is considered to be in Normal Operation if there are no alarm indications.

M S 7:49

CH4 %LEL

0 20.9

ppm

H2S

ppm

0.0

Figure 5: Measuring Mode Display

1. Check Mark: If BMP.RMDR is set to ON and a bump test is not due, a check mark appears in the upper left corner of the LCD.

2. Heart Symbol: The heart symbol in the upper left corner of the LCD indicates the operation status and blinks when normal. A microprocessor error causes the heart symbol to stop flashing or to disappear.

3. M : The instrument is operating in User Mode, Maintenance Mode, or Gas Select Mode. S : The instrument is operating in Stealth Mode.

4. Battery Icon: Displays one of three levels of battery charge

: Fully charged

: Low charge

: Depleted, needs charging

5. Clock: The current time is displayed at the top of the LCD in 24-hour format.

6. Fan/Pump Icon: The X-shaped icon next to the battery indicates that the pump is active and will rotate in place when functioning properly.

Confirmation/Non-Compliance Indicator
If the BEEP.SEL menu item in User Mode is set to anything other than OFF, the GX-Force beeps periodically to confirm that it’s operating or to indicate a non-compliance (see page 91).

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Chapter 3: Operation · 29

Monitoring an Area

1. Start up the GX-Force as described above in “Start Up” on page 21. It is now in Measuring Mode.

7:49

CH4 %LEL
0

20.9

ppm

H2S

ppm

0.0

2. Take the GX-Force to the monitoring area.
3. Wait at least 15 seconds and monitor the display for gas readings. Allow readings to stabilize to determine the gas concentrations present.
4. If a gas alarm occurs, take appropriate action. See page 36.
5. Do not expose the GX-Force to rain.
6. The GX-Force’s IP 67 ratings do not imply that the GX-Force will detect gas during and after exposure to those conditions. If exposure occurs, dry the instrument with a cloth and perform a bump test as described on page 64.
7. If the GX-Force gets exposed to flammable liquids: a. Wipe the instrument off with a cloth dampened with water. b. Replace the filters as described on page 100 and page 103 if they become saturated. c. Perform a bump test as described on page 64.
8. If you suspect that the GX-Force is not operating correctly: a. Take the GX-Force to a fresh air environment and perform a demand zero as described on page 27. b. Perform a bump test as described on page 64.
Combustible Gas Detection
There are three issues to keep in mind when monitoring for combustible gas.
Response
The combustible gas sensor responds to any combustible gas. The standard calibrated target gas for the combustible gas channel is methane (CH4). If the instrument is setup for and calibrated to a different combustible gas, such as hexane or propane, the gas name right above the readings displays as “HC”.
· Automatic Conversion
The GX-Force can automatically display converted target gas readings if the instrument’s calibrated target gas is methane or isobutane. See “Combustible Sensor Target Gas Conversion (LIST)” on page 49.

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GX-Force Operator’s Manual

· Manual Conversion
You can manually calculate a converted target gas reading using Table 4 if the instrument’s calibrated target gas is methane. The table lists the conversion factors for several hydrocarbon gases if the GX-Force is calibrated to methane.
To use this table, multiply the display reading on the combustible gas channel by the factor in the appropriate row to obtain the actual gas concentration. For example, if you are detecting ethylene and the display reads 10% LEL for the combustible gas channel, you actually have 10% LEL x 0.83 = 8.3% LEL ethylene present.
Table 4: LEL Hydrocarbon Conversion Factors

Gas

LEL Conversion Factor (from CH4 Cal.)

Gas

Acetone

2.22

IPA

LEL Conversion Factor (from CH4 Cal.)
1.64

Acetylene

1.43

Isobutane

1.10

Benzene

2.50

MEK

2.63

Butadiene

1.52

Methane

1.00

Cyclopentane 1.45

Methanol

1.82

DME

1.16

MIBK

4.00

Ethane

0.94

MMA

3.33

Ethanol

1.96

Nonane

9.09

Ethyl Acetate 2.86

Propane

1.12

Ethylene

0.83

Propylene

0.97

Heptane

3.13

THF

2.33

Hexane

1.89

Toluene

4.55

Hydrogen

0.95

Xylene

7.69

Overscale Protection
The GX-Force protects the combustible gas sensor by temporarily turning off the sensor power if levels exceeding 100% LEL are detected. Nevertheless, combustible gas concentrations above 100% LEL can still affect the zero level or calibration of the combustible gas sensor.

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Chapter 3: Operation · 31

CAUTION: Do not expose the combustible gas sensor to high concentrations of combustible gas such as that from a butane lighter. Exposure to high concentrations of combustible gas may adversely affect the performance of the sensor.
CAUTION: Any rapid increase in the combustible gas reading on the combustible gas channel followed by a declining or erratic reading may indicate a gas concentration above the LEL which may be hazardous.
Damaging Gases
Some gases such as silicone vapors, chlorinated hydrocarbons, and sulphur compounds can contaminate the sensor’s detection elements. This causes sensor damage and/or a reduced response to combustible gas. Make every effort to avoid these gases. The H2S scrubber disks protect the combustible sensor from H2S, but you should avoid other sulphur compounds.
HC Gas List Alarm
An HC Gas List alarm can occur at startup or after a calibration. The combustible gas sensor actually contains 2 separate sensors: a standard catalytic sensor and a backup sensor that is resistant to sensor poisons like silicone. An HC Gas List alarm indicates that the standard sensor has a reduced output, possibly due to one or more sensor poisons in the environment and that the poison-resistant sensor is being used to provide gas readings. The poison-resistant sensor has a limited list of detectable gases. The table shown on page 49 shows which gases can and cannot be detected after receiving an HC Gas List alarm. If your application requires detection of a gas still detectable after an HC Gas List condition (like methane or isobutane), there is no need to replace the combustible gas sensor. However, if your application requires detection of a gas not detectable after an HC Gas List condition (like methanol or ethanol), you must replace the combustible gas sensor as soon as possible.
Oxygen-Enriched Atmospheres
The GX-Force is not intended for use in oxygen-enriched atmospheres.
WARNING: Do not use the GX-Force in an environment with an oxygen concentration above 21%.

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GX-Force Operator’s Manual

H2-Compensated CO Detection
Instruments with an H2-compensated CO sensor installed do not display H2 readings, but if the H2 concentration rises above 2000 ppm, the instrument will go into an “H2 rich” alarm.

7:49

CH4 %LEL
0

20.9

ppm

H2S

ppm

7:49

CH4 %LEL
0

20.9

ppm

H2S

ppm

rich

NOTE: The H2-compensated CO sensor may not effectively compensate for higher levels of H2 if exposed to temperatures above 40°C for longer than 15 minutes. Under these conditions, it can appear to the instrument that the H2 concentration has exceeded 2000 ppm, the max concentration that can be compensated for, resulting in a CO reading higher than the actual CO level.
Interference Information
Some gases interfere with CO and H2S sensors. For a complete list of these gases, see page 137.
Alarms
This section covers alarm indications in Measuring Mode. It also describes responding to and resetting an alarm condition.
NOTE: False alarms may be caused by radio frequency (RF) or electromagnetic (EMI) interference. Keep the GX-Force away from RF and EMI sources such as radio transmitters or large motors.
Alarm Indications
The GX-Force buzzer sounds an alarm, the LEDs flash, and the vibrator pulses when any sort of alarm condition or failure occurs. If the GX-Force is operating in Stealth Mode, the buzzer does not sound and the vibrator’s operation depend on the VIB setting in Gas Select Mode’s STEALTH menu item. See page 133 for more information.
NOTE: If an alarm condition occurs while you are in Display Mode, the GX-Force automatically returns to the Measuring Mode screen.
NOTE: If an alarm occurs while you are in Leak Check’s Display Mode, the GX-Force does NOT exit that mode.

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Chapter 3: Operation · 33

Table 5 summarizes the types of alarms produced by the GX-Force and their indications.
Table 5: Alarm Types and Indications

Alarm Type

Visual Indications

Other Indications

Warning
Concentration of gas rises above the Warning setting or falls below the Warning setting for O2.

· Affected channel’s gas reading, gas name, and units flash
· WARNING appears at the bottom of the LCD
· Alarm LEDs flash in circle sequence once per second
· Backlight turns on

· High-low tone sounding once per second
· Vibrator pulses once per second

Alarm
Concentration of gas rises above the Alarm setting or falls below the Alarm setting for O2.

· Affected channel’s gas reading, gas name, and units flash
· ALARM appears at the bottom of the LCD
· Alarm LEDs flash in circle sequence twice per second
· Backlight turns on

· High-low tone sounding twice per second
· Vibrator pulses twice per second

Alarm H
Concentration of gas rises above the Alarm H setting.

· Affected channel’s gas reading, gas name, and units flash
· ALARM H appears at the bottom of the LCD
· Alarm LEDs flash in circle sequence twice per second
· Backlight turns on

· High-low tone sounding twice per second
· Vibrator pulses twice per second

TWA or STEL Concentration of CO or H2S rises above the TWA or STEL alarm setting.
H2 RICH (for instruments with H2-compensated CO sensors) Concentration of hydrogen rises above 2000 ppm (parts per million).

· Affected channel’s gas reading, gas name, and units flash
· TWA or STEL appears at the bottom of the LCD
· Alarm LEDs flash in circle sequence once per second
· Backlight turns on
· H2 and rich alternate in the lower right corner
· Alarm LEDs flash twice per second · Backlight turns on

· High-low tone sounding once per second
· Vibrator pulses once per second
· High-low tone sounding twice per second
· Vibrator pulses twice per second

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Alarm Type
Over Range
Minus Over Range
Low Battery Warning Dead Battery Alarm Sensor Failure HC Gas List Clock Failure Flow Failure

Table 5: Alarm Types and Indications

Visual Indications

Other Indications

· Affected channel’s gas reading is replaced with a flashing
· Gas name and units flash
· OVER appears at the bottom of the LCD
· Alarm LEDs flash in circle sequence twice per second
· Backlight turns on

· High-low tone sounding twice per second
· Vibrator pulses twice per second

· Affected channel’s gas reading is replaced with a flashing
· Gas name and units flash
· M OVER appears at the bottom of the LCD
· Alarm LEDs flash in circle sequence twice per second
· Backlight turns on

· High-low tone sounding twice per second
· Vibrator pulses twice per second

· The last bar in the battery icon starts flashing.
· Alarm LEDs flash once every 4 seconds

Pulsing tone once every 4 seconds

· Gas readings disappear. FAIL appears in the middle of the screen and BATTERY appears at the bottom of the screen.
· Alarm LEDs flash once per second

Double pulsing tone once per second

· SENSOR appears at the bottom of the screen and the failed sensor(s) are indicated with FAIL under the gas name.
· Alarm LEDs flash once per second

Double pulsing tone once per second

· READ GAS LIST IN MANUAL appears on the screen.
· Alarm LEDs flash once per second

Double pulsing tone once per second

· FAIL appears in the middle of the screen and CLOCK appears at the bottom of the screen.
· Alarm LEDs flash once per second

Double pulsing tone once per second

· FAIL appears in the middle of the screen and FLOW appears at the bottom of the screen.
· Alarm LEDs flash once per second

Double pulsing tone once per second

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Chapter 3: Operation · 35

Alarm Type
Pump Failure
System Failure

Table 5: Alarm Types and Indications

Visual Indications

Other Indications

· FAIL appears in the middle of the screen and PUMP appears at the bottom of the screen.
· Alarm LEDs flash once per second

Double pulsing tone once per second

· FAIL SYSTEM appears at the bottom of the screen and an error code displays in the middle
· Alarm LEDs flash once per second

Double pulsing tone once per second

Responding to Alarms
This section describes response to gas, over range, battery, sensor failure, HC Gas List, clock failure, flow/pump failure alarms, and system failure alarms.
Responding to Gas Alarms
1. Determine which gas alarm has been activated.
2. Follow your established procedure for an increasing gas condition or a decreasing oxygen condition.

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GX-Force Operator’s Manual

3. Reset or silence the alarm as necessary or allowed. Alarm silence can be turned on or off using the ALM.SLNC menu item in Maintenance Mode (see page 118) or the GX-Force Data Logger Management Program (see the GX-Force Data Logger Management Program Operator’s Manual).
Table 6 summarizes resetting and silencing alarms for all LATCH and SILENCE combinations that are possible.
Table 6: Resetting and Silencing Alarms

LATCH: ON (factory setting)

LATCH: OFF

ALARM SILENCE: ON
ALARM SILENCE: OFF (factory setting)

· Press the POWER MODE or AIR buttons to silence the buzzer.
· If the gas concentration was still above the alarm level when the button was pressed, the LED arrays continue to flash, the vibrator continues to pulse, and the GXForce continues to display the current alarm level.
· The gas reading must fall below (or rise above for an oxygen low alarm) an alarm setting before you can reset the alarm, the LEDs, and the vibrator using the POWER MODE or AIR buttons.
NOTE: If PASS–W is ON (factory setting: OFF), press POWER MODE and AIR simultaneously and then enter the user-set password to reset an alarm condition.

· Press the POWER MODE or AIR buttons to silence the buzzer.
· The POWER MODE or AIR buttons will not reset the alarm.
· The alarm, LEDs, and vibrator will automatically reset when gas reading falls below (or rises above for an oxygen low alarm) an alarm setpoint.

· Pressing POWER MODE or AIR will not silence buzzer.
· The gas reading must fall below (or rise above for an oxygen low alarm) an alarm setting before you can reset the alarm condition using the POWER MODE or AIR buttons.

· Pressing POWER MODE or AIR will not silence buzzer.
· The alarm condition will automatically reset when the gas reading falls below (or rises above for an oxygen low alarm) an alarm setpoint.

Responding to an H2 RICH Alarm (H2-Compensated CO Sensor Only)
The H2 RICH alarm automatically clears once the hydrogen level decreases below 2000 ppm (parts per million).

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Chapter 3: Operation · 37

Responding to Over Range Alarms
WARNING: An over range condition may indicate an extreme combustible gas, toxic gas, or oxygen concentration. Confirm the gas concentration with a different GX-Force or with another gas detecting device.
CAUTION: High off-scale readings may indicate an explosive concentration.
PRUDENCE: Des lectures élevées hors échelle peuvent indiquer une concentration explosive.
1. Determine which channel is in alarm. 2. Follow your established procedure for an extreme gas condition. 3. If LATCH is set to ON (factory setting) in Maintenance Mode, reset the alarm using POWER
MODE or AIR once the alarm condition clears. If PASS – – W is turned ON (factory setting is OFF), you must press POWER MODE and AIR at the same time and then enter a user-set password to reset an alarm condition. When the password screen appears, adjust each digit with the AIR button and press the POWER MODE button to move on to the next digit. Once the password is entered, the alarm condition resets.
7:49
0 0 0 0
PASS – – W
4. Calibrate the GX-Force as described on page 59. 5. If the over range condition continues or if you are not able to successfully calibrate the unit,
you may need to replace the sensor that has triggered the over range alarm. 6. If the over range condition continues after you have replaced the sensor, contact RKI
Instruments, Inc. for further instructions.

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Responding to Battery Alarms
WARNING: The GX-Force is not operational as a gas monitoring device during a dead battery alarm. Take the Model GX-Force to a non-hazardous area and recharge the batteries as described in “Recharging the Lithium Ion Battery Pack” on page 99.
The GX-Force is fully functional during a low battery warning. However, only 1-2 hours of operating time remain. The amount of operating time left depends on LCD backlight use and the alarm frequency. Recharge the battery as soon as possible as described in “Recharging the Lithium Ion Battery Pack” on page 99.
NOTE: Alarms and the LCD back light consume battery power and reduce the amount of operating time remaining.
Responding to Sensor Failure Alarms
1. Determine which sensor triggered the sensor failure alarm.
2. Calibrate the failed sensor, as described on page 59.
3. If the sensor failure continues or if the sensor could not be calibrated, replace the sensor as described on page 106.
4. If the sensor failure condition continues after you have replaced the sensor, contact RKI Instruments, Inc. for further instructions.
Responding to an HC Gas List Alarm
An HC Gas List alarm can occur at startup or after a calibration.
1. Press POWER MODE to acknowledge the alarm. The combustible gas sensor actually contains 2 separate sensors: a standard catalytic sensor and a backup, poison-resistant sensor that is resistant to sensor poisons like silicone. An HC Gas List alarm indicates that the standard sensor has a reduced output, possibly due to one or more sensor poisons in the environment, and that the poison-resistant sensor is being used to provide gas readings. The poison-resistant sensor has a limited list of detectable gases. Table 10 on page 49 shows which gases can and cannot be detected after receiving an HC Gas List alarm. If your application requires detection of a gas still detectable after an HC Gas List condition (like methane or isobutane), there is no need to replace the combustible gas sensor. However, if your application requires detection of a gas not detectable after an HC Gas List condition (like methanol or ethanol), you must replace the combustible gas sensor as soon as possible.

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Chapter 3: Operation · 39

Responding to Clock Failure Alarms
A clock failure alarm occurs if the unit’s internal clock malfunctions. A clock failure alarm might also occur if the battery becomes too drained during storage. See page 108 for storage information.
7:49
FAIL
CLOCK
1. Press POWER MODE to proceed to Measuring Mode.
CAUTION: If you operate the instrument after a clock failure, data will still be logged but the date/time will be incorrect. Set the date/time as described on page 95 as soon as possible to ensure logged data uses the correct date/time.
2. Attempt to set the date using the DATE menu item in User Mode. See page 95. 3. If the date cannot be set correctly, contact RKI Instruments, Inc. as soon as possible.
Responding to a Flow Failure Alarm
Flow failure alarms can be caused by clogged dust filters or blockages in the instrument’s internal flow paths. 1. If a flow failure occurs, the flow failure alarm screen displays.
7:49
FAIL
FLOW
2. Inspect the internal pump’s dust filter and the probe’s dust filter and replace them if either is clogged or saturated by liquid (see page 103 and page 105).
3. If the low flow alarm persists after filter replacement, contact RKI Instruments, Inc. to schedule a repair.
Responding to a Pump Failure Alarm
Pump failure alarms can be caused by the instrument’s internal pump.
NOTE: The pump’s motor grease may solidify if not used for long periods of time. For longterm storage, the instrument should be turned on every 6 months to let the pump run. See “Chapter 7: Storage and Disposal” on page 108.

40 · Chapter 3: Operation

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1. If a pump failure occurs, the pump failure alarm screen displays.
7:49
FAIL

PUMP

2. The pump failure alarm indicates that the pump must be replaced. Contact RKI Instruments, Inc. to schedule replacement.
Responding to System Failure Alarms
1. If a system failure occurs, the system failure screen displays an error code as shown below:
7:49
FAIL
021
SYSTEM

2. The error code meanings are shown in Table 7:
Table 7: Error Code Explanation

Error Code Explanation

000

ROM failure

010

RAM failure

021

FRAM failure

031

FLASH memory failure

080

Circuit voltage anomaly

081

PCB failure

082

Temperature sensor failure

3. If the error code is anything but 031 as shown above, the instrument cannot be used. Contact RKI Instruments, Inc. as soon as possible.
If the error code is 031, you may press POWER MODE to continue into Measuring Mode if the instrument must be used temporarily.
CAUTION: There will be no data logging function if you operate the instrument after a 031 system failure. Contact RKI Instruments, Inc. as soon as possible.

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Chapter 3: Operation · 41

Saving Snap Log Data
The GX-Force is capable of logging all channel readings at a given moment and can store up to 256 logs at one time. When the maximum number of logs has been reached, any new logs will overwrite the oldest data logged on the instrument. All saved snap log data can be reviewed using the REC.DATA screen in Display Mode. Refer to “Viewing Snap Log Data (REC.DATA)” on page 56 for more information.
1. While in Measuring Mode, press and hold AIR and POWER MODE for several seconds. The snap log number, station ID, date and time, and value are displayed in the following sequence:

7:49
no 001
REC.DATA

7:49
23 – 12.20 7:49
YES.MODE

7:49
Stn Id
S_ID_001

7:49

CH4 %LEL
0

20.9

ppm

H2S

ppm

0.0

NO.AIR

2. Press POWER MODE to save the captured snap log. The instrument confirms the log was saved before displaying the next log screen.

7:49

SAVED

002
REC.DATA

3. To return to the normal Measuring Mode, press AIR. To save another snap log, press POWER MODE.

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Data Logging

NOTE: If the GX-Force is used in Leak Check Mode, only the CH4 channel will be logged while it is in Leak Check Mode.

Additionally, interval trends, alarm trends, and alarm events are not recorded during measurement in Leak Check Mode. See “Snap Log Mode, Leak Check Mode Operation” on page 143.

The GX-Force logs Measuring Mode gas readings, alarm data, calibration data, and saved snap logs to its internal memory. Logged data can be downloaded to a computer via the USB-C port on the bottom of the instrument.
To utilize the GX-Force’s downloading capability, you will need the GX-Force Data Logger Management Program, a USB Type-C to USB Type-A data cable, and a computer with a USB port that runs one of the following operating systems: Windows 8, Windows 10, or Windows 11. The GX-Force Data Logger Management Program is available at www.rkiinstruments.com/gxforce.
The data logging capacity depends on how often the GX-Force stores data, how many channels are active, and how often the GX-Force is turned on and off. Table 8 illustrates how much data logging time is available for the various interval times. It assumes that the unit has three sensors, is only turned on once, and there are no alarm occurrences. The data logging interval time must be set using the GX-Force Data Logger Management Program.
Table 8: Data Logging Capacity

Interval Time

Data Logging Time

10 seconds

10 hours

20 seconds

20 hours

30 seconds

30 hours

1 minute

60 hours

3 minutes

180 hours

5 minutes (factory setting) 300 hours

10 minutes

600 hours

For a complete description of the Data Logger Management Program and procedures for downloading data to a computer, see the GX-Force Data Logger Management Program Operator’s Manual.

GX-Force Operator’s Manual

Chapter 3: Operation · 43

Chapter 4: Display Mode

This section describes Display Mode which is accessible from Measuring Mode. See Table 9 for a list of Display Mode’s menu items, a short description of each item, and the page number for further description.
Table 9: Display Mode Menu Items

Display Mode Menu Item

Description

MODE.SEL (page 46)

Switches from Normal Mode to Leak Check Mode
NOTE: Only appears if L.C. MODE is set to ON (factory setting) in Maintenance Mode and GAS.COMB is set to either CH4 (factory setting) or i-C4H10 in Gas Select Mode.

LIGHT (page 47) Turns the LED flashlight on and off

PEAK (page 47) Displays each sensor’s Peak reading

STEL (page 48) TWA (page 48) LIST (page 49)

Displays the STEL readings (CO and H2S only)

Displays the TWA readings (CO and H2S only)

Changes the target gas for the catalytic sensor
NOTE: Only appears if DISP.SET is set to ON in User Mode (factory setting) and if CH4 or isobutane are selected for the combustible gas in Gas Select Mode.

· CH4 (methane) · i-C4H10 (isobutane) · H2 (hydrogen) · CH3OH (methanol) · C2H2 (acetylene) · C2H4 (ethylene) · C2H6 (ethane) · C2H5OH (ethanol) · C3H6 (propylene) · C3H6O (acetone) · C3H8 (propane) · C4H6 (butyne) · C5H10 (cyclopentane) · C6H6 (benzene)

· n-C6H14 (hexane) · C7H8 (toluene) · n-C7H16 (heptane) · C8H10 (xylene) · n-C9H20 (nonane) · EtAc (ethyl acetate) · IPA (isopropyl alcohol) · MEK (methyl ethyl ketone) · MMA (methyl methacrylate) · DME (dimethyl ether) · MIBK (methyl isobutyl ketone) · THF (tetrahydrofuran) · n-C5H12 (n-pentane)

PUMP.OFF (page 51)

Turns the internal pump off to conserve battery
NOTE: Only appears if DISP.SET is set to ON in User Mode (factory setting) and if POFF.DISP is set to ON in Maintenance Mode (factory setting is OFF).

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Display Mode Menu Item USER ID (page 52)
STN ID (page 53)
CAL.DATA (page 54)
BMP.DATA (page 55)
REC.DATA (page 56)
TEMP (page 56)
ALARM–P (page 57)

Table 9: Display Mode Menu Items
Description
Displays and updates the instrument’s User ID
NOTE: Only appears if DISP.SET is set to ON in User Mode (factory setting) and if ID DISP is set to ON in Maintenance Mode (factory setting is OFF).
Displays and updates the instrument’s Station ID
NOTE: Only appears if DISP.SET is set to ON in User Mode (factory setting) and if ID DISP is set to ON in Maintenance Mode (factory setting is OFF).
Displays each sensor’s last calibration date
NOTE: Only appears if CAL.RMDR is set to ON in User Mode (factory setting).
Displays each sensor’s last bump test date
NOTE: Only appears if BMP.RMDR is set to ON in User Mode (factory setting is OFF).
Displays all saved snap log data
Displays the current date, time, and temperature Displays alarm setpoints

Tips for Using Display Mode
· To enter Display Mode and scroll from one menu item to the next or skip an item when a question is asked, press POWER MODE.
· To enter an item, press AIR. · To change a flashing parameter, press AIR.
· To reverse the direction of movement in a list (ie. from down to up or vice versa):
a. Press and hold AIR. b. Immediately press POWER MODE and then release both buttons. · To exit from an entered-information screen and go back to the main menu, press POWER MODE.
· To exit Display Mode and return to Measuring Mode, press and hold both AIR and POWER MODE together.
NOTE: With the exception of the PUMP.OFF screen, each screen displays for 20 seconds. If no button is pressed within 20 seconds, the GX-Force automatically returns to Measuring Mode. If the pump is turned off using the PUMP.OFF setting, the PUMP.OFF screen will display until the pump is turned back on.

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Chapter 4: Display Mode · 45

Mode Select (MODE.SEL)
NOTE: The Mode Select screen is only available for instruments with firmware 08085 or higher.
NOTE: The MODE.SEL screen only appears if L.C. MODE is set to ON (factory setting) in Maintenance Mode and GAS.COMB is set to either CH4 (factory setting) or i-C4H10 in Gas Select Mode.
The MODE.SEL screen is used to switch between Leak Check Mode and Normal Mode. It is recommended to perform a fresh air adjustment after switching between modes (Leak Check or Normal Mode). See “Performing a Demand Zero” on page 27. 1. While in Measuring Mode, press POWER MODE once. The MODE.SEL menu item appears.
7:49

MODE.SEL

2. Press AIR to enter the Mode Select screen.

3. Press AIR to scroll between Normal Mode and Leak Check Mode.
Press POWER MODE to enter the selected mode. If no mode is selected after 20 seconds, the unit automatically starts up in the mode that’s displayed.

7:49
SELECt

7:49
AIR
SELECt

NORMAL

LEAK

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LED Flashlight (LIGHT)
The LIGHT menu item can be used to turn the GX-Force’s LED flashlight on and off. 1. While in Measuring Mode, press POWER MODE until LIGHT appears.
7:49
OFF

LIGHT
2. Press AIR to change the current setting. 3. Press POWER MODE to save the desired setting and move to the next menu item.

Peak Screen (PEAK)
The peak screen displays the highest (lowest for oxygen) concentrations detected since the GXForce was turned on. Peak readings are stored in the GX-Force’s memory until a higher level is detected (lower for oxygen), the peak reading is cleared, or the GX-Force is turned off.
The lunch break feature enables the GX-Force to save peak readings when it is turned off so it can continue with the same peaks when it is turned on again. See page 90 for instructions to turn the lunch break feature on (default is OFF).

NOTE: If PASS – – W is set to ON, the peak reading cannot be cleared.

To clear the peak readings, do the following:

1. While in Measuring Mode, press POWER MODE until PEAK appears.

7:49

CH4 %LEL
24

17.3

ppm

135

H2S

ppm

37.5

PEAK

2. Press and hold AIR until the screen prompts you to release it.

7:49

CLEAr

HOLD AIR

RELEASE

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Chapter 4: Display Mode · 47

3. The peak readings are cleared and the unit returns to the Peak Screen. If you do not want to clear the peak readings, release AIR before the above screen sequence occurs. The unit returns to the Peak Screen.
STEL Screen (STEL)
The STEL Screen displays the short term exposure limit (STEL) readings for H2S and CO only. The STEL reading is the average reading over the last 15 minutes.
7:49

ppm

H2S

ppm

2.0

STEL

TWA Screen (TWA)
The TWA Screen displays the time weighted average (TWA) readings for H2S and CO only.
7:49

ppm

H2S

ppm

0.5

TWA

The TWA reading is the average reading over the last 8 hours. If 8 hours have not elapsed since the last time the TWA reading was cleared, the average is still calculated over 8 hours. The missing readings are assigned a 0 value. If LUNCH is set to OFF (factory setting), the TWA is cleared when the GX-Force is turned off.
If LUNCH is set to ON, the GX-Force remembers TWA readings when it is turned off so it can continue them when it is turned on again. See page 90 for instructions to turn the lunch break feature on (default is OFF).

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Combustible Sensor Target Gas Conversion (LIST)
NOTE: This screen only appears if DISP.SET in User Mode is set to ON (factory setting) and if the instrument’s calibrated target gas is CH4 or iC4H10 (select target gas in Gas Select Mode’s GAS.COMB item, calibrate with target gas in User Mode’s GAS CAL item).

NOTE: Leak Check Mode is only supported for methane (CH4) and isobutane (i-C4H10). If any other gas option is selected in LIST menu of Display Mode, the GX-Force will only display the combustible gas readings in terms of methane or isobutane, whichever the instrument was calibrated to.

The LIST screen allows you to select a converted target gas based on a CH4 or i-C4H10 calibration. It does not change the calibrated target gas. You must go to Gas Select Mode’s GAS.COMB item to change the calibrated target gas (see page 129).
Selecting a converted target gas from the LIST screen (based on a CH4 or i-C4H10 calibration) does not provide the same reading accuracy as selecting a calibrated target gas in Gas Select Mode’s GAS.COMB item and calibrating with that target gas in User Mode.
Selecting a converted target gas in LIST does not mean that the combustible gas sensor will respond only to that gas. The combustible gas sensor responds to a number of gases regardless of the target gas selection.

NOTE: If H2 is selected as the target gas, either in Gas Select Mode or in Display Mode, the sensor will only respond to the gases available during an HC Gas List Condition (see
Table 10). It will not respond to heavy hydrocarbons.

If you select a new converted target gas, the change is saved after you turn the instrument off and on.
Table 10: Available HC Gas Conversions

Available Converted Gases

Based on Calibrated Target Gas Available

Gas

(Selected in Gas Select Mode)

Converted Target Gases During HC

CH4

i-C4H10

Gas List Condition

(methane)

(isobutane)

CH4 (methane)

–

i-C4H10 (isobutane)

–

H2 (hydrogen)

CH3OH (methanol)

C2H2 (acetylene)

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Chapter 4: Display Mode · 49

Table 10: Available HC Gas Conversions

Available Converted Gases

Based on Calibrated Target Gas Available

Gas

(Selected in Gas Select Mode)

Converted Target Gases During HC

CH4

i-C4H10

Gas List Condition

(methane)

(isobutane)

C2H4 (ethylene)

C2H6 (ethane)

C2H5OH (ethanol)

C3H6 (propylene)

C3H6O (acetone)

C3H8 (propane)

C4H6 (butyne)

C5H10 (cyclopentane)

C6H6 (benzene)

n-C6H14 (hexane)

C7H8 (toluene)

n-C7H16 (heptane)

C8H10 (xylene)

n-C9H20 (nonane)

EtAc (ethyl acetate)

IPA (isopropyl alcohol)

MEK (methyl ethyl ketone)

MMA (methyl methacrylate) O

DME (dimethyl ether)

MIBK (methyl isobutyl ketone) O

THF (tetrahydrofuran)

n-C5H12 (n-pentane)

x = not available O = available

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1. While in Measuring Mode, press POWER MODE until LIST appears.
7:49
HC GAS

LIST
2. Press AIR to enter the screen. The current gas flashes at the bottom of the screen.
7:49
HC GAS SELECt
CH4
3. Use AIR to scroll through the list of gases. 4. When the desired gas is displayed, press POWER MODE. The changes are saved and the
instrument returns to the LIST screen. 5. The gas formula displays at the bottom of the Measuring Mode screen. The gas selection
remains selected if you turn the instrument off and on again.

Turning the Pump Off (PUMP.OFF)

WARNING: The GX-Force is not a gas monitoring device while the pump is off.
The PUMP.OFF screen only appears if DISP.SET in User Mode is set to ON (factory setting) and if P.OFF DISP in Maintenance Mode is set to ON (factory setting is OFF). This menu item turns the internal pump off to prevent draining the battery while the instrument is not in active use. This can be useful if the instrument is being used intermittently throughout a monitoring session.
1. While in Measuring Mode, press POWER MODE until the PUMP.OFF screen sequence appears.

7:49
On

PUMP.OFF

YES / AIR

NO / MODE

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Chapter 4: Display Mode · 51

2. To turn the internal pump off, press AIR. The pump will shut off and the pump fan icon next to the battery icon will disappear.
The M icon indicates that the instrument can only exit this screen when the pump is turned back on.

M 7:49

OFF

PUMP.ON

YES.MODE

3. Press POWER MODE to turn the internal pump back on and return to the PUMP.OFF menu item in Display Mode.

Changing the User ID (USER ID)
The USER ID screen only appears if DISP.SET in User Mode is set to ON (factory setting) and if ID DISP in Maintenance Mode is set to ON (factory setting is OFF). Use this screen to select a user ID from the 128 user IDs that are stored in the GX-Force’s memory. Before a user ID is selected on a brand new instrument, the user ID is “———-“. The factory-installed user IDs have a “U_ID_XXX” format. The user ID provides a way to identify the GX-Force user during a data logging session. User IDs can only be selected in this menu item. In order to edit the 128 user IDs, you must use the GX-Force Datalogging Program.
1. While in Measuring Mode, press POWER MODE until the USER ID screen sequence appears.

7:49
USEr Id

U_ID_001

CHG / AIR

NO / MODE

2. To change the User ID, press AIR. The current User ID flashes.
7:49
USEr Id
U_ID_002

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3. Use AIR to scroll to the desired User ID. 4. Press POWER MODE to save the User ID and return to the USER ID screen in Display Mode.

Changing the Station ID (STN ID)
The STN ID screen appears if DISP.SET in User Mode is set to ON (factory setting) and if ID DISP in Maintenance Mode is set to ON (factory setting is OFF). Use this screen to select a station ID from the 128 station IDs that are stored in the GX-Force’s memory. Before a station ID is selected on a brand new instrument, the station ID is “———-“. The factory-installed station IDs have a “S_ID_XXX” format. The station ID provides a way to identify the GX-Force location during a data logging session. Station IDs can only be selected in this menu item. In order to edit the 128 station IDs, you must use the GX-Force Data Logger Program.
1. While in Measuring Mode, press POWER MODE until the STN ID screen sequence appears.

7:49
Stn Id

S_ID_001

CHG / AIR

NO / MODE

2. To change the station ID, press AIR. The current Station ID flashes.
7:49
Stn Id
S_ID_002
3. Use AIR to scroll to the desired station ID. 4. Press POWER MODE to save the station ID and return to the STN ID screen in Display Mode.

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Chapter 4: Display Mode · 53

Last Successful Calibration Date (CAL DATA)
The CAL DATA screen shows the date of each installed sensor’s last successful calibration. This screen only appears if CAL.RMDR is set to ON in User Mode. 1. While in Measuring Mode, press POWER MODE until CAL DATA appears.
7:49
dISP

CAL DATA
2. Press AIR to enter the CAL DATA screen and to scroll through the installed sensors.

7:49
23 – 3. 8. CH4
CAL DATA
AIR
7:49
23 – 3. 8. O2
CAL DATA

7:49 AIR
23 – 3. 8.
H2S
CAL DATA
AIR
7:49
23 – 3. 8.
CO
CAL DATA
AIR

3. When you are done viewing the last calibration date for the sensors, press POWER MODE to return to the CAL DATA screen in Display Mode.

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Last Successful Bump Test Date (BMP.DATA)
The BMP.DATA screen shows the date of each installed sensor’s last successful bump test. This screen only appears if BMP.RMDR is set to ON. 1. While in Measuring Mode, press POWER MODE until BMP.DATA appears.
7:49
dISP

BMP.DATA
2. Press AIR to enter the BMP.DATA screen and to scroll through the installed sensors.

7:49
23 – 3. 8. CH4
BMP.DATA
AIR
7:49
23 – 3. 8. O2
BMP.DATA

7:49 AIR
23 – 3. 8.
H2S
BMP.DATA
AIR
7:49
23 – 3. 8.
CO
BMP.DATA
AIR

3. When you are done viewing the last bump test date for the sensors, press POWER MODE to return to the BMP.DATA screen in Display Mode.

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Chapter 4: Display Mode · 55

Viewing Snap Log Data (REC.DATA)
The REC.DATA screen shows the date and measurement data for each snap log saved on the instrument. 1. While in Measuring Mode, press POWER MODE until REC.DATA appears.
7:49
dISP

REC.DATA

2. Press AIR to enter the REC.DATA screen and to scroll through the saved snap logs. Press POWER MODE to view the desired snap log’s details.

7:49

23 –

3.08

7:49

POWER MODE

M001

7:49

CH4 %LEL
0

20.9

ppm

H2S

ppm

0.0

SID_001

3. When finished viewing the instrument’s snap log data, press AIR and POWER MODE together to return to the REC.DATA screen in Display Mode.

Date, Time, Temperature Screen (TEMP)
The TEMP screen shows the instrument’s date and time and the surrounding area’s temperature.
7:49
23 – 3.08 7:49
22°C

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Alarm Points Screen (ALARM–P)
The Alarm Points Screen shows the gas alarm settings for all active channels. 1. While in Measuring Mode, press POWER MODE until ALARM–P appears.
7:49
dISP

ALARM–P
2. Press AIR. The Full Scale Settings screen appears and shows full scale settings for each channel.
3. Use AIR to scroll through the Warning, Alarm, Alarm H, STEL, and TWA settings.

M 7:49

CH4 %LEL
100

40.0

ppm

2000

H2S

ppm

200.0

F.S.

AIR

7:49

CH4 %LEL
10

19.5

ppm

H2S

ppm

5.0

WARNING

AIR

7:49

CH4 %LEL
25

18.0

ppm

H2S

ppm

30.0

ALARM

7:49

AIR

CH4 %LEL

50 23.5

ppm

1200

H2S

ppm

100.0

ALARM H

AIR

7:49

ppm

200

H2S

ppm

5.0

STEL

AIR

7:49

ppm

H2S

ppm

1.0

TWA

AIR

7:49 AIR

ESCAPE

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Chapter 4: Display Mode · 57

4. While viewing the alarm settings for an alarm point, press AIR and POWER MODE at the same time to simulate the alarm conditions. The buzzer will sound, the LEDs will flash, and the instrument will vibrate just as it would if the displayed condition was actually happening.
5. Press POWER MODE to return to the Alarm Points Screen.

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Chapter 5: User Mode and Calibration

Overview

This section describes the GX-Force in User Mode. See Table 11 for a list of the items found in User Mode, the page that the menu item’s instructions can be found on, and a short description of the menu item.
Table 11: User Mode Menu Items

User Mode Menu Item
BUMP (page 64)

Description Perform a bump test.

BUMP CYL X

Perform a bump test on the gases selected for Cylinder X (A-E cylinders available)

START ESCAPE

Begin the warmup sequence and enter Measuring Mode. Return to the BUMP menu item.

GAS CAL (page 70) Perform a fresh air adjustment, perform a span adjustment, change the calibration gas concentration, set the cylinder group.

AIR CAL (page 70)

Perform a fresh air adjustment.

AUTO.CAL (page 71)

AUTO.CAL Perform an automatic span adjustment on the gases

CYL X

selected for Cylinder X (A-E cylinders available).

START

Begin the warmup sequence and enter Measuring Mode.

CAL–P

Set the calibration gas concentration for each gas.

ESCAPE

CYL SEL

Assign a cylinder (A-E) to each gas (all 4 gases set to Cylinder A is the default). For single cal operation, you would assign each gas its own cylinder.

ESCAPE

Return to the AUTO.CAL menu item.

Return to the GAS CAL menu item.

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Chapter 5: User Mode and Calibration · 59

User Mode Menu Item CAL SET (page 81)
BUMP.SET (page 83)

Table 11: User Mode Menu Items

Description

Change calibration parameters.

CAL.RMDR (page 81)

ON (factory setting): The instrument notifies the user upon startup when a calibration is due. Notification type depends on CAL.EXPD setting below.
OFF: No notification upon startup when a calibration is due.

CAL.INT (page 82)

How often the instrument needs to be calibrated. Options: 1 – 1000 days (factory setting is 90 days)

CAL.EXPD (page 82)

Defines what action must be taken if a calibration is due upon startup.
CONFIRM (factory setting): press AIR to acknowledge that calibration is due and continue to Measuring Mode.
CANT USE: Cannot enter Measuring Mode until a successful calibration is performed.
NONE: A screen indicates that calibration is due but warmup sequence continues.

ESCAPE

Return to the CAL SET menu item in User Mode.

Change bump test parameters.

SETTING (page 83)

GAS.TIME How long gas is applied during a bump test. Choices: 30 (factory setting), 45, 60, 90 seconds

BMP.RMDR (page 86)

CHECK

Percentage of calibration gas concentration that the bump test reading must be within in order to pass bump.
Options: 10%, 20%, 30%, 40%, 50% (factory setting)

CAL. TIME

How long gas is applied during a calibration. GAS.TIME is deducted from this time.
Options: 90 (factory setting) or 120 seconds

AUTO. CAL

ON (factory setting): If a bump test fails, a calibration automatically starts.
OFF: If a bump test fails, a calibration does not automatically start.

ESCAPE

Return to the SETTING menu item in BUMP.SET.

ON: The instrument notifies the user upon startup when a bump test is due. Notification type depends on BMP.EXPD setting below.
OFF (factory setting): No notification upon startup when a bump test is due.

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User Mode Menu Item BUMP.SET (page 83) cont.
ALARM — P (page 87) LUNCH (page 90)
BEEP (page 91)

Table 11: User Mode Menu Items

Description

BMP.INT (page 86)

How often the instrument needs to be bump tested. Options: 0 – 30 days (factory setting is 30 days)

BMP.EXPD (page 87)

Defines what action must be taken if a bump test is due upon startup. CONFIRM (factory setting): Press AIR to acknowledge that bump test is due and continue to Measuring Mode. CANT USE: Cannot enter Measuring Mode until a successful bump test is performed. NONE: A screen indicates that bump test is due but warmup sequence continues.

ESCAPE

Return to the BUMP.SET menu item in User Mode.

Set alarm points for all channels (WARNING, ALARM, ALARM H, STEL, TWA) or reset all alarms to their default settings (DEF.ALMP).

ESCAPE

Return to the ALARM–P menu item in User Mode.

ON: Lunch break feature is on. Instrument asks if you want to resume TWA and PEAK readings at startup.
OFF (factory setting): Lunch break feature is off. Instrument resets TWA and PEAK readings every time it’s turned on.

Set confirmation beep parameters.

BEEP.SEL (page 91)

LED: LEDs flash and instrument vibrates based on interval defined in BEEP.INT to confirm instrument is still operating.
BUZZER: Buzzer sounds and instrument vibrates based on interval defined in BEEP.INT to confirm instrument is still operating.
LED+BUZZ: LEDs flash, buzzer sounds, and instrument vibrates based on interval defined in BEEP.INT to confirm instrument is still operating.
BUMP/CAL: LEDs flash based on interval defined in BEEP.INT if bump test or calibration is due.
ALM.ALRT: LEDs flash based on interval defined in BEEP.INT if instrument goes into a gas alarm.

B/C/ALM: LEDs flash based on interval defined in BEEP.INT if a) bump test is due, b) calibration is due, or c) instrument goes into a gas alarm.
OFF (factory setting): No alerts to confirm instrument is still operating or that a bump test or calibration is due.

BEEP.INT (page 92)

Confirmation alert interval. Confirmation type defined in BEEP.SEL.
Options: 0.5 minute and 1 to 99 minutes in 1 minute increments. The factory setting is 5 minutes.

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Chapter 5: User Mode and Calibration · 61

Table 11: User Mode Menu Items

User Mode Menu Item

Description

BEEP (page 91) cont.

ESCAPE

Return to the BEEP menu item in User Mode.

BL TIME (page 93) How long the back light stays on after the last button press Options: 0 – 255 seconds or OFF. The factory setting is 30 seconds.

KEY.TONE (page 93)

ON (factory setting): Buzzer sounds when button is pressed. OFF: Buzzer does not sound when button is pressed.

DISP.SET (page 94)

OFF: LIST, USER ID, STN ID, and PUMP.OFF screens do not appear in Display Mode.
ON (factory setting): LIST item appears in Display Mode. USER ID and STN ID screens appear if ID DISP in Maintenance Mode is also set to ON. The PUMP.OFF screen appears if POFF.DISP in Maintenance Mode is also set to ON.

ZERO.SUP (page 94)

ON (factory setting): Not intended for field adjustment. The suppression values are: · Combustible Gas: 2% LEL · O2: 0.5% volume · H2S: 0.3 ppm · CO: 2 ppm NOTE: Only appears if ZSUP.DISP is set to ON in Maintenance Mode

ZERO.FLW (page 95)

ON (factory setting): Not intended for field adjustment. Oxygen channel does not support zero follower functionality.
NOTE: Only appears if ZFLW.DISP is set to ON in Maintenance Mode

DATE (page 95)

Set the instrument’s date and time.

PASS – – W (page 96)

ON: User Mode is password-protected. Factory-set password is 0000. OFF (factory setting): User Mode is not password-protected.

ROM/SUM (page 97)

Displays the GX-Force’s sensor and main ROM/SUM numbers

START (page 97)

Press POWER MODE to begin the warmup sequence and enter Measuring Mode.

Tips for Using User Mode
· To scroll from one menu item to the next, press AIR. To reverse the scrolling direction: a. Press and hold AIR. b. Immediately press POWER/MODE and then release both buttons. c. The scrolling direction returns to the original direction when you exit and reenter a menu.
· To skip an item when a question is asked, press AIR.

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· To enter an item and to save any changes, press POWER MODE.
· To change a flashing parameter, press AIR. To reverse the direction of change (ie. from increasing to decreasing or vice versa):
a. Press and hold AIR. b. Immediately press POWER MODE and then release both buttons. · To exit an entered menu item without saving a change, press and hold AIR and POWER MODE for a few seconds.

Entering User Mode

WARNING: The GX-Force is not in operation as a gas detector while in User Mode.

1. Take the GX-Force to a non-hazardous location and turn it off if it is on.
2. Press and hold AIR, then press and hold POWER MODE. When the instrument beeps once, release the buttons.
3. The screen that appears depends on the PASS – – W setting in User Mode. · If PASS – – W is set to OFF (factory setting), continue to Step 6. · If PASS – – W is set to ON, continue to Step 4.

M 7:49

M 7:49
0 0 0 0

BUMP PASS – – W set to OFF

PASS – – W PASS – – W set to ON

4. If PASS – – W has been set to ON in User Mode, a password screen appears. The first digit is flashing.

5. Use AIR to select each password number then press POWER MODE to save it and move on to the next number. To go back a number, press and hold AIR and POWER MODE for a few seconds. To reverse the direction of change (ie. from increasing to decreasing or vice versa): a. Press and hold AIR.
b. Immediately press POWER MODE and then release both buttons.

6. The BUMP menu item appears.

M 7:49

GX-Force Operator’s Manual

BUMP

Chapter 5: User Mode and Calibration · 63

7. M at the top of the screen indicates that the GX-Force is in User Mode. 8. Use AIR to move through the User Mode menu items.

Performing a Bump Test (BUMP)

Bump test the instrument before each day’s use with a known concentration of each target gas. The instrument does not need to be calibrated unless it does not pass the bump test. To bump test the GX-Force, you will need:
· Known calibrating samples of the gases being detected.
Table 12: Calibration Concentration Limits

Channel
Combustible Gas Oxygen Hydrogen Sulfide

Min. Cal. Gas Max. Cal. Gas Concentration Concentration

1% LEL

75% LEL

0.0%

17.0%

0.5 ppm

200.0 ppm

Carbon Monoxide

12 ppm

2,000 ppm

· Demand flow regulator · Non-absorbent tubing · Sample hose and probe (if used during normal operation) 1. Confirm that the GX-Force’s calibration gas values match the concentrations listed on the calibration gas cylinder(s) as described on page 76.
2. Confirm that your cylinder selections are appropriate as described on page 79.
3. Install the demand flow regulator onto the calibration cylinder.
4. Connect the sample tubing to the demand flow regulator.
5. If used during normal operation, install the sample hose and probe onto the GX-Force inlet fitting. Make sure the probe’s two halves are tightened firmly together to avoid leaks that can affect the calibration.
6. While in User Mode, press AIR to scroll to BUMP.
M 7:49

BUMP

64 · Chapter 5: User Mode and Calibration

GX-Force Operator’s Manual

7. Press POWER MODE. The display shows the gases assigned to Cylinder A and their assigned bump test values (see page 76 if the bump test values do not match the calibration gas cylinder’s concentrations). The bottom of the screen alternates between “CYL A” and “BUMP”.

M 7:49

CH4 %LEL
50

12.0

ppm

H2S

ppm

25.0

CYL A

M 7:49

CH4 %LEL
50

12.0

ppm

H2S

ppm

25.0

BUMP

8. If necessary, use AIR to scroll to the Bump screen for the gas(es) you want to bump test. As shipped from the factory, combustible gas, O2, H2S, and CO are assigned to Cylinder A. If an H2-compensated CO sensor is installed, H2 is assigned to Cylinder D, but there is no reason to bump test the H2 response.
9. Make sure the GX-Force has been turned on for at least 45 seconds before continuing.

10. Connect the sample tubing from the demand flow regulator to either the GX-Force’s inlet fitting or the rigid tube on the probe (if in use) then quickly press POWER MODE to begin the bump test countdown.

11. The gas readings flash, the bottom of the screen alternates between “APPLY” and “BUMP”, and the top of the screen counts down from the time set in BUMP.SETSETTINGGAS.TIME.

M 7:49

CH4 %LEL
0

20.9

ppm

H2S

ppm

0.0

APPLY

M 7:49

CH4 %LEL
0

20.9

ppm

H2S

ppm

0.0

BMP

NOTE: To back out of the gas application screen without performing the bump test, press AIR and POWER MODE together.

GX-Force Operator’s Manual

Chapter 5: User Mode and Calibration · 65

12. At the end of the countdown, the instrument analyzes the results. Follow the flow chart to determine the bump test outcome.

Multiple Cylinders Assigned?

Bump test passed?

AUTO.CAL On? (default is on)

Auto start after successful bump set to on? (default is on)

Calibration passed?

Multiple Cylinders Assigned?

Auto start after successful cal set to on? (default is on)

*NOTE: Auto start after successful cal parameter set using the GX-Force Datalogger Management Program.

Figure 6: Bump Test Flow Chart

66 · Chapter 5: User Mode and Calibration

GX-Force Operator’s Manual

Option A from Flow Chart

Option B from Flow Chart

Option C from Flow Chart

· Bump test passed · Multiple cylinders assigned

· Bump test passed · One cylinder assigned · Auto Start After Successful
Bump set to ON (factory setting)

· Bump test passed
· One cylinder assigned
· Auto Start After Successful Bump set to OFF (factory setting is ON)

1. The instrument indicates that all channels passed the bump test. Use AIR to scroll between the bump test results and the bump test gas readings.

M 7:49

CH4 %LEL

ppm

BMP/CAL

M 7:49

CH4 %LEL

ppm

H2S

ppm

BMP/CAL

M 7:49

CH4 %LEL

ppm

H2S

ppm

BMP/CAL

AIR

M 7:49

CH4 %LEL
47

ppm

11.9

BMP/

M 7:49

CH4 %LEL
47

11.9

ppm

H2S

ppm

22.0

BMP/

2. Disconnect the tubing from the probe.
3. Press POWER MODE to move to the BUMP CYL X screen for the next cylinder.
4. Unscrew the demand flow regulator from the first cylinder and screw it into the next cylinder.
5. Repeat Step 10 through Step 12. 6. After the last cylinder is bump
tested, press POWER MODE to go to the START item in the BUMP menu. 7. Disconnect the tubing from the probe. 8. Unscrew the regulator. 9. Press POWER MODE to enter Measuring Mode.

2. Disconnect the tubing from the probe.
3. Unscrew the demand flow regulator from the calibration cylinder.
4. Press POWER MODE to enter Measuring Mode.

M 7:49

CH4 %LEL
47

11.9

ppm

H2S

ppm

22.0

BMP/

2. Disconnect the tubing from the probe.
3. Unscrew the demand flow regulator from the calibration cylinder.
4. Press POWER MODE to return to the START item in the BUMP menu.
5. Press POWER MODE to enter Measuring Mode.

GX-Force Operator’s Manual

Chapter 5: User Mode and Calibration · 67

Option D from Flow Chart
· Bump test failed · A-CAL set to OFF (factory setting is
ON)

1. The instrument shows which channels passed or failed the bump test. The LEDs flash and the buzzer sounds. Use AIR to scroll between the results and the readings.

M 7:49

CH4 %LEL

ppm

H2S

ppm

BMP/CAL

AIR

M 7:49

CH4 %LEL
47

11.9

ppm

H2S

ppm

2.0

BMP/

2. Disconnect the tubing from the probe.
3. Unscrew the demand flow regulator from the calibration cylinder.
4. Press POWER MODE to return to the BUMP CYL A item in the BUMP menu.
5. Use AIR to scroll to START and Press POWER MODE to enter Measuring Mode.
6. Calibrate the GX-Force as soon as possible.

Option E from Flow Chart
· Bump test failed · A-CAL set to ON (factory setting) · Calibration failed

1. A calibration immediately and automatically starts. Continue to apply the calibration gas.
2. The calibration time is the difference between the GAS.TIME and the CAL.TIME values defined in the BUMP.SETSETTING item in User Mode.

M 7:49

CH4 %LEL
30

H2S

ppm

2.0

AUTO CAL

3. The instrument shows which channels passed or failed the bump test/calibration. The LEDs flash and the buzzer sounds. Use AIR to scroll between the results and the readings.

M 7:49

CH4 %LEL

FP P

ppm

H2S

ppm

BMP/CAL

AIR

M 7:49

CH4 %LEL
30

ppm

11.9

H2S

ppm

2.0

BMP/

AIR

M 7:49

CH4 %LEL
42

H2S

ppm

2.5

/CAL

4. Disconnect the tubing from the probe.
5. Unscrew the demand flow regulator from the calibration cylinder.
6. Press POWER MODE to return to the BUMP CYL A item in the BUMP menu.
7. Use AIR to scroll to START and press POWER MODE to enter Measuring Mode.

Option F from Flow Chart
· Bump test failed · A-CAL set to ON (factory setting) · Calibration passed · Multiple cylinders assigned
1. A calibration immediately and automatically starts. Continue to apply the calibration gas.
2. The calibration time is the difference between the GAS.TIME and the CAL.TIME values defined in the BUMP.SETSETTING item in User Mode.
M 7:49
CH4 %LEL
30

AUTO CAL
3. The instrument shows which channels passed or failed the bump test/calibration. Use AIR to scroll between the results and the readings.

M 7:49

CH4 %LEL

FP P

ppm

BMP/CAL

AIR

M 7:49

CH4 %LEL
30

11.9

ppm

BMP/

AIR

M 7:49
CH4 %LEL
42

/CAL
4. Disconnect the tubing from the probe.
5. Press POWER MODE to move to the BUMP CYL X screen for the next cylinder.
6. Unscrew the demand flow regulator from the first cylinder and screw it into the next cylinder.
7. Repeat Step 10 through Step 12. 8. After the last cylinder is bump
tested, press POWER MODE to go to the START item in the BUMP menu. 9. Unscrew the regulator. 10. Press POWER MODE to enter Measuring Mode.

68 · Chapter 5: User Mode and Calibration

GX-Force Operator’s Manual

Option G from Flow Chart

Option H from Flow Chart

· Bump test failed · A-CAL set to ON (factory setting) · Calibration passed · One cylinder assigned · Auto Start After Successful Cal set to ON
(factory setting)

· Bump test failed · A-CAL set to ON (factory setting) · Calibration passed · One cylinder assigned · Auto Start After Successful Cal set to
OFF (factory setting is ON)

M 7:49

CH4 %LEL
30

H2S

ppm

2.0

AUTO CAL

3. The instrument shows which channels passed or failed the bump test/ calibration. Use AIR to scroll between the results and the readings.

M 7:49

CH4 %LEL
30

H2S

ppm

2.0

AUTO CAL

3. The instrument shows which channels passed or failed the bump test/ calibration. Use AIR to scroll between the results and the readings.

M 7:49

CH4 %LEL

FP P

ppm

H2S

ppm

BMP/CAL

M 7:49

CH4 %LEL

FP P

ppm

H2S

ppm

BMP/CAL

AIR

M 7:49

CH4 %LEL
30

11.9

ppm

H2S

ppm

12.0

BMP/

M 7:49

CH4 %LEL
30

11.9

ppm

H2S

ppm

12.0

BMP/

AIR

M 7:49

CH4 %LEL
42

H2S

ppm

20.5

/CAL

4. Disconnect the tubing from the probe. 5. Unscrew the demand flow regulator
from the calibration cylinder.
6. Press POWER MODE to enter Measuring Mode.

M 7:49

CH4 %LEL
42

H2S

ppm

20.5

/CAL

4. Disconnect the tubing from the probe. 5. Unscrew the demand flow regulator
from the calibration cylinder.
6. Press POWER MODE to return to the START item in the BUMP menu.
7. Press POWER MODE to enter Measuring Mode.

GX-Force Operator’s Manual

Chapter 5: User Mode and Calibration · 69

Performing a Calibration (GAS CAL)
Calibration Notes
· To fully calibrate the sensors, you must do a fresh air adjustment (AIR CAL) and a span adjustment (AUTO.CAL).
· Bump test the instrument before each day’s use with a known concentration of each target gas. A bump test can be done in User Mode’s BUMP item or by applying gas in Measuring Mode. The instrument does not need to be calibrated unless it does not pass the User Mode bump test or does not respond appropriately, as defined by the user, in Measuring Mode.
· The hydrogen response for the H2-compensated CO sensor needs to be calibrated both monthly and when the sensor is replaced.
Performing a Demand Zero (AIR CAL)
1. Find a fresh air environment, an environment of normal oxygen content (20.9%) that is free of toxic and combustible gases.
2. While in User Mode, press AIR to scroll to GAS CAL.
M 7:49

GAS CAL
3. Press POWER MODE. The AIR CAL menu item appears.
M 7:49

AIR CAL

4. Press POWER MODE to enter the AIR CAL menu.

M 7:49

CH4 %LEL
0

20.9

ppm

H2S

ppm

0.0

AIR CAL

5. Make sure the GX-Force has been turned on for at least 45 seconds before continuing.

70 · Chapter 5: User Mode and Calibration

GX-Force Operator’s Manual

6. Press and hold AIR until the screen prompts you to release it.

M 7:49

Air CAL

Adj

HOLD AIR

RELEASE

7. If the fresh air adjustment passes, the instrument returns to the GAS CAL menu.

8. If the fresh air adjustment fails, “FAIL AIR” displays. Press POWER MODE to acknowledge the failure. See “Troubleshooting” on page 98.

Performing a Span Adjustment in AUTO.CAL
Preparing for a Span Adjustment
To adjust the span on the GX-Force, you will need the following: · Known concentrations of the gases being detected
Table 13: Calibration Concentration Limits

Channel

Min. Cal.

Max. Cal.

Concentration Concentration

Combustible Gas

1% LEL

75% LEL

Oxygen

0.0%

17.0%

Hydrogen Sulfide

0.5 ppm

200.0 ppm

Carbon Monoxide

12 ppm

2,000 ppm

Hydrogen (for H2-compensated CO sensor); needs monthly calibration

25 ppm

2,000 ppm

· Demand flow regulator · Non-absorbent tubing · Sample hose and probe (if used during normal operation) 1. Confirm that the GX-Force’s calibration gas values match the concentrations listed on the calibration gas cylinder(s) as described on page 76.
2. Confirm that your cylinder selections are appropriate as described on page 79.
3. Install the demand flow regulator onto the 3-gas or 4-gas calibration cylinder.
4. Connect the sample tubing to the demand flow regulator.
5. If used during normal operation, install the sample hose and probe onto the GX-Force inlet fitting. Make sure the probe’s two halves are tightened firmly together to avoid leaks that can affect the calibration.

GX-Force Operator’s Manual

Chapter 5: User Mode and Calibration · 71

Performing a Span Adjustment
1. While in User Mode, press AIR to scroll to GAS CAL.
M 7:49

GAS CAL
2. Press POWER MODE. The AIR CAL menu item appears. 3. Use AIR to scroll to the AUTO.CAL menu item.
M 7:49

AUTO.CAL

4. Press POWER MODE. The display shows the gases assigned to Cylinder A and their assigned calibration values (see page 76 if the calibration values do not match the calibration gas cylinder’s concentrations). The bottom of the screen alternates between “CYL A” and “AUTO.CAL”.

M 7:49

CH4 %LEL
50

12.0

ppm

H2S

ppm

25.0

CYL A

M 7:49

CH4 %LEL
50

12.0

ppm

H2S

ppm

25.0

AUTO.CAL

5. If necessary, use AIR to scroll to the AUTO.CAL screen for the gas(es) you want to calibrate. As shipped from the factory, combustible gas, O2, H2S, and CO are assigned to Cylinder A. If an H2-compensated CO sensor is installed, H2 is assigned to Cylinder D.
6. Make sure the GX-Force has been turned on for at least 45 seconds before continuing.
7. Connect the tubing from the demand flow regulator to either the GX-Force’s inlet fitting or the rigid tube on the probe (if in use) then quickly press POWER MODE to begin the span adjustment countdown.

72 · Chapter 5: User Mode and Calibration

GX-Force Operator’s Manual

8. The gas readings flash and the bottom of the screen alternates between “APPLY” and “AUTO.CAL”.

M 7:49

CH4 %LEL
0

20.9

ppm

H2S

ppm

0.0

APPLY

M 7:49

CH4 %LEL
0

20.9

ppm

H2S

ppm

0.0

AUTO.CAL

NOTE: To back out of the gas application screen without performing the bump test, press AIR and POWER MODE together.

9. Allow the gas to flow for 1 minute. 10. Press POWER MODE. 11. Follow the flow chart to determine the calibration outcome.

Calibration passed?

Multiple Cylinders

Assigned?

Auto start after successful cal set to on? (default is on)

*NOTE: Auto start after successful cal parameter set using the GX-Force Datalogger Management Program.
Figure 7: Calibration Flow Chart

GX-Force Operator’s Manual

Chapter 5: User Mode and Calibration · 73

Option A from Flow Chart · Calibration passed · Multiple cylinders assigned
1. The instrument indicates that all channels passed the calibration.
M 7:49
PASS

Option B from Flow Chart
· Calibration passed · One cylinder assigned · Auto Start After Successful Cal set to ON (factory setting)
1. The instrument indicates that all channels passed the calibration.
M 7:49
PASS

AUTO.CAL 2. The instrument shows the current gas readings.

M 7:49

CH4 %LEL
51

11.9

ppm

AUTO.CAL

3. If MAX.SPAN is set to ON (default is OFF, see page 133), the response reading’s max adjustment is displayed. A max span of 100% LEL on the combustible channel indicates that the reading could have been adjusted up to 100% LEL. If the max span value is close to the calibration gas value, the sensor should be replaced soon. The max adjustment is either twice the calibration value or full scale, whichever is lower. The max adjustment indicated for the oxygen channel is 25.0% volume.

M 7:49

CH4 %LEL
100

25.0

ppm

MAX.SPAN

4. If the combustible gas sensor is nearing expiration, Display Mode’s LIST item becomes limited. Press POWER MODE to acknowledge. See page 39 for a description of the HC Gas List condition and page 49 for the limited conversion list.

M 7:49

rEAd GAS

LISt

MANUAL

5. Disconnect the tubing from the probe. 6. The instrument continues to the AUTO.CAL CYL X
screen. 7. Unscrew the regulator from the first cylinder and screw it
into the next cylinder. 8. Press POWER MODE to start the next cylinder’s
calibration. 9. Repeat Step 9 through Step 11. 10. After the last cylinder is calibrated, the instrument
continues to the START item in the AUTO.CAL menu. 11. Disconnect the tubing from the probe.

12. Unscrew the regulator.

13. Press POWER MODE to enter Measuring Mode.

AUTO.CAL 2. The instrument shows the current gas readings.

M 7:49

CH4 %LEL
51

11.9

ppm

H2S

ppm

25.2

AUTO.CAL

M 7:49

CH4 %LEL
100

25.0

ppm

H2S

ppm

48.5

MAX.SPAN

M 7:49

rEAd GAS

LISt

MANUAL

5. Disconnect the tubing from the probe. 6. Unscrew the regulator. 7. The instrument automatically begins its warmup
sequence and enters Measuring Mode.

74 · Chapter 5: User Mode and Calibration

GX-Force Operator’s Manual

Option C from Flow Chart
· Calibration passed · One cylinder assigned · Auto Start After Successful Cal set to OFF (factory
setting is ON)
1. The instrument indicates that all channels passed the calibration.
M 7:49
PASS

AUTO.CAL

2. The instrument shows the current gas readings.

M 7:49

CH4 %LEL
51

11.9

ppm

H2S

ppm

25.2

AUTO.CAL

M 7:49

CH4 %LEL
100

25.0

ppm

H2S

ppm

48.5

MAX.SPAN

M 7:49

rEAd GAS

LISt

MANUAL

5. Disconnect the tubing from the probe. 6. Unscrew the regulator.
7. The instrument continues to the START item in the

AUTO.CAL menu.

8. Press POWER MODE to enter Measuring Mode.

Option D from Flow Chart · Calibration failed

1. The instrument indicates which channels failed the calibration.

M 7:49

CH4 %LEL
FAIL

11.9

ppm

H2S

ppm

25.2

AUTO.CAL

2. Disconnect the tubing from the probe. 3. Unscrew the regulator. 4. Press POWER MODE to return to the AUTO.CAL
CYL X screen in the AUTO.CAL menu.
5. See “Troubleshooting” on page 98.

GX-Force Operator’s Manual

Chapter 5: User Mode and Calibration · 75

Setting the Calibration Values in CAL–P
1. While in User Mode, press AIR to scroll to GAS CAL.
M 7:49

GAS CAL
2. Press POWER MODE. The AIR CAL menu item appears. 3. Use AIR to scroll to the AUTO.CAL menu item.
M 7:49

AUTO.CAL

4. Press POWER MODE. The AUTO.CAL screen for gases assigned to Cylinder A appears.

5. Use AIR to scroll to CAL – – P.

M 7:49

CAL – – P
6. Press POWER MODE. The combustible gas channel appears.
M 7:49
CH4 %LEL
– – –
CAL – – P

76 · Chapter 5: User Mode and Calibration

GX-Force Operator’s Manual

7. Use AIR to scroll to the channel whose calibration gas value you want to change.

M 7:49 AIR

M 7:49
CH4 %LEL
– – –

H2S

ppm

– – –

CAL – – P

AIR

M 7:49

– – –

AIR M 7:49

ppm

– – –

CAL – – P

AIR M 7:49

AIR
ESCAPE
8. Press POWER MODE. The calibration value begins to flash. In the example below, the combustible gas channel is selected.
M 7:49
CH4 %LEL
50
CAL – – P

GX-Force Operator’s Manual

Chapter 5: User Mode and Calibration · 77

9. Use AIR to adjust the calibration gas value. The calibration gas value in the instrument must match the value listed on the calibration gas cylinder you are using for that channel. Limits on the calibration gas value are shown in Table 14.
Table 14: Calibration Concentration Limits

Channel

Min. Cal.

Max. Cal.

Concentration Concentration

Combustible Gas

1% LEL

75% LEL

Oxygen

0.0%

17.0%

Hydrogen Sulfide

0.5 ppm

200.0 ppm

Carbon Monoxide

12 ppm

2,000 ppm

Hydrogen (for H2-compensated CO sensor); needs monthly calibration

25 ppm

2,000 ppm

10. Press POWER MODE to save the change. The calibration gas value stops flashing and the unit returns to the channel selection screen.
11. Repeat Step 7 through Step 10 for any other channels that need to be changed.
12. Use AIR to scroll to ESCAPE.
13. Press POWER MODE. The instrument returns to the CAL–P menu item in the Auto Cal Menu.
14. Press AIR to scroll to ESCAPE.
15. Press POWER MODE. The instrument returns to the AUTO.CAL menu item in the GAS CAL Menu.
16. See “Exiting the GAS CAL Menu” on page 81 to return to User Mode.

78 · Chapter 5: User Mode and Calibration

GX-Force Operator’s Manual

Making Cylinder Selections in CYL SEL
The CYL SEL menu item allows you to group channels together for calibration. As shipped from the factory, the standard 4 channels (combustible gas, O2, H2S, and CO) are assigned to Cylinder A. As shipped from the factory, the H2 response for the H2-compensated CO sensor is assigned to Cylinder D. There are 5 cylinder assignments available: A, B, C, D, and E. To calibrate each channel separately, assign each channel to a different cylinder (ie. Cylinder A: combustible gas, Cylinder B: O2, Cylinder C: H2S, Cylinder D: CO). 1. While in User Mode, press AIR to scroll to GAS CAL.
M 7:49
GAS CAL
2. Press POWER MODE. The AIR CAL menu item appears. 3. Use AIR to scroll to the AUTO.CAL menu item.
M 7:49
AUTO.CAL
4. Press POWER MODE. The Auto Cal screen for gases assigned to Cylinder A displays. 5. Use AIR to scroll to CYL SEL.
M 7:49
CYL SEL
6. Press POWER MODE. The combustible gas channel displays.
M 7:49
CH4 %LEL
– – –
CYL SEL

GX-Force Operator’s Manual

Chapter 5: User Mode and Calibration · 79

7. Use AIR to scroll to the channel whose cylinder assignment you want to change.

M 7:49
CH4 %LEL
– – –

CYL SEL

AIR

M 7:49

– – –

CYL SEL

M 7:49 AIR

H2S

ppm

– – –

CYL SEL

AIR

M 7:49

ppm

– – –

CYL SEL

AIR

M 7:49

ESCAPE
8. Press POWER MODE. The current setting flashes. In the example below, the combustible gas channel is selected.
M 7:49
CH4 %LEL
A
CYL SEL
9. Use AIR to change the cylinder assignment. The choices are A, B, C, D, and E. 10. Press POWER MODE to save the change. The cylinder assignment stops flashing and the unit
returns to the channel selection screen. 11. Repeat Step 7 through Step 10 for any other channels that need to be changed. 12. Use AIR to scroll to ESCAPE. 13. Press POWER MODE. The instrument returns to the CYL SEL menu item in the Auto Cal
Menu. 14. Press AIR to scroll to ESCAPE.

80 · Chapter 5: User Mode and Calibration

GX-Force Operator’s Manual

15. Press POWER MODE. The instrument returns to the AUTO.CAL menu item in the GAS CAL menu.
16. See “Exiting the GAS CAL Menu” on page 81 to return to User Mode.
Exiting the GAS CAL Menu
1. While in the GAS CAL menu, press AIR to scroll to ESCAPE. 2. Press POWER MODE. The instrument returns to the GAS CAL menu item in User Mode. 3. See “Entering Measuring Mode (START)” on page 97 to enter Measuring Mode.
Setting Calibration Parameters (CAL SET)
The CAL SET menu item has 4 items: CAL.RMDR, CAL.INT, CAL.EXPD, and ESCAPE. 1. While in User Mode, press AIR to scroll to CAL SET.
M 7:49

CAL SET
2. Press POWER MODE. The CAL.RMDR menu item appears.
M 7:49

CAL.RMDR
CAL.RMDR
ON (factory setting): The GX-Force gives an indication at start up if it is due for calibration. The type of indication depends on the CAL.EXPD setting (see page 82). OFF: The GX-Force does not give an indication at start up if it is due for calibration. 1. After entering the CAL SET menu, press AIR to scroll to CAL.RMDR.
M 7:49

CAL.RMDR
2. Press POWER MODE. The current setting flashes.

GX-Force Operator’s Manual

Chapter 5: User Mode and Calibration · 81

3. Use AIR to display the desired setting.
4. Press POWER MODE to save the setting and return to the CAL.RMDR menu item.
5. See “Exiting the CAL SET Menu” on page 83 to return to User Mode.
CAL.INT
This setting defines the amount of time between calibrations. The time can be set in 1 day increments. The minimum setting is 1 day and the maximum setting is 1000 days. The factory setting is 90 days. 1. After entering the CAL SET menu, press AIR to scroll to CAL.INT.
M 7:49

CAL.INT
2. Press POWER MODE. The current setting flashes.
3. Use AIR to display the desired setting.
4. Press POWER MODE to save the setting and return to the CAL.INT menu item.
5. See “Exiting the CAL SET Menu” on page 83 to return to User Mode.
CAL.EXPD
This item defines what indication is given during start up when calibration is due and CAL.RMDR is set to ON. CONFIRM (factory setting): The GX-Force gives an indication at start up if calibration is past due. Press AIR to continue without calibrating or press POWER MODE to perform a calibration. CANT USE: The GX-Force gives an indication at start up if calibration is past due. Press POWER MODE to enter User Mode and perform a calibration. Pressing AIR has no effect. A successful calibration must be performed in order to use the instrument. NONE: The GX-Force gives an indication at startup if calibration is past due. If desired, press POWER MODE to perform a calibration but it is not necessary to acknowledge the calibrat

Documents / Resources

RKI INSTRUMENTS 71-0626 GX-Force Portable Gas Detector [pdf] Instruction Manual
71-0626, 71-0626 GX-Force Portable Gas Detector, GX-Force Portable Gas Detector, Portable Gas Detector, Gas Detector, Detector

References

User Manual

RKI INSTRUMENTS 71-0626 GX-Force Portable Gas Detector Instruction Manual

71-0626 GX-Force Portable Gas Detector

Specifications

Product Information

Operation

Maintenance

Storage

General Parts List

FAQ

Q: Where can I find the GX-Force manual?

Q: How do I register my GX-Force product?

Documents / Resources

References

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