MaxO2+ Industrial Oxygen Analyzer

Overview

Base Unit Description

• Provides unparalleled performance and reliability due to an advanced design.
• Features an extra-life oxygen sensor with approximately 1,500,000 O2 percent hours (2-year warranty).
• Durable, compact design for comfortable, hand-held operation and easy cleaning.
• Operates using two AA Alkaline batteries (2 x 1.5 Volts) for approximately 5000 hours of continuous use. AA Lithium batteries may be used for extended life.
• Oxygen-specific, galvanic sensor achieves 90% of final value in approximately 15 seconds at room temperature.
• Large, easy-to-read, 3 1/2-digit LCD display for readings in the 0-100% range.
• Simple operation with easy one-key calibration.
• Includes self-diagnostic check of analog and microprocessor circuitry.
• Features low battery indication.
• Equipped with a calibration reminder timer that alerts the operator via a calibration icon on the LCD display to perform a unit calibration.

Component Identification

Figure 1 illustrates the components of the MaxO2+ analyzer:

• 1. 3-DIGIT LCD DISPLAY: Displays oxygen concentrations from 0 – 105.0%. Also shows error codes and calibration codes.
• 2. LOW BATTERY INDICATOR: Located at the top of the display, activated when battery voltage is below normal operating level.
• 3. "%" SYMBOL: Appears next to the concentration number during normal operation.
• 4. CALIBRATION SYMBOL: Located at the bottom of the display, activates when calibration is necessary.
• 5. ON/OFF KEY: Used to turn the device on or off.
• 6. CALIBRATION KEY: Used to calibrate the device. Holding for over three seconds initiates calibration mode.
• 7. SAMPLE INLET CONNECTION: Port for connecting to determine oxygen concentration.

Operating Instructions

Getting Started

Protect Tape

? NOTE: Prior to turning on the unit, remove the protective film covering the threaded sensor face. Wait approximately 20 minutes for the sensor to reach equilibrium after removing the film.

Automatic Calibration

After turning on the unit, it will automatically calibrate to room air. The display should stabilize and read 20.9%.

ℹ️ CAUTION: The device assumes a percent oxygen concentration during calibration. Ensure 100% oxygen or ambient air concentration is applied during calibration for correct results.

Figure 2 shows the sample gas connection setup.

Checking Oxygen Concentration

(After the unit has been calibrated):

1. Connect the Tygon tubing to the bottom of the analyzer by threading the barbed adapter onto the oxygen sensor (Figure 2, B).
2. Attach the other end of the sample hose to the sample gas source and initiate flow at a rate of 1-10 liters per minute (2 liters per minute recommended).
3. Ensure the unit is powered ON using the "ON/OFF" key.
4. Allow the oxygen reading to stabilize (approximately 30 seconds or more).

Calibrating the MAXO2+ Oxygen Analyzer

? NOTE: Maxtec recommends using medical grade USP or >99% purity oxygen for calibration.

The MAXO2+ Analyzer should be calibrated upon initial power-up and recommended weekly thereafter. A one-week timer starts with each calibration, displaying a reminder icon "CAL" when calibration is due. Calibration is advised if the last procedure date is unknown or if measurement values are in question. Start calibration by pressing the Calibration key for over 3 seconds. The MAXO2+ automatically detects if calibrating with 100% oxygen or 20.9% oxygen (normal air).

? DO NOT attempt to calibrate to any other concentration.

Calibration Requirements

For ID testing or optimum accuracy, a new calibration is required when:

• The measured O2 percentage in 100% O2 is below 99.0%.
• The measured O2 percentage in 100% O2 is above 101.0%.
• The CAL reminder icon is blinking on the LCD.

If unsure about the displayed O2 percentage, refer to "Factors Influencing Accurate Readings".

A simple calibration can be made with the sensor open to ambient air. For optimum accuracy, Maxtec recommends a closed-loop circuit with gas flow across the sensor. Calibrate using the same circuit and flow rate as for measurements.

In Line Calibration (Flow Diverter – Tee Adapter)

1. Attach the diverter to the MAXO2+ by threading it onto the bottom of the sensor.
2. Insert the MAXO2+ into the center position of the tee adapter (Figure 2, A).
3. Attach an open-ended reservoir to the end of the tee adapter. Start calibration flow of oxygen at two liters per minute. (Six to 10 inches of corrugated tubing works well as a reservoir).
4. Allow the oxygen to saturate the sensor. While a stable value is usually observed within 30 seconds, allow at least two minutes for complete saturation.
5. If the MAXO2+ is not already ON, press the "ON" button.
6. Press the Cal button until "CAL" appears on the display (approx. 3 seconds). The analyzer will seek a stable sensor signal and good reading, then display the calibration gas.

? NOTE: Analyzer will display "Cal Err St" if the sample gas has not stabilized.

Direct Flow Calibration (Barb)

1. Attach the Barbed Adapter to the MAXO2+ by threading it onto the bottom of the sensor.
2. Connect the Tygon tube to the barbed adapter (Figure 2, B).
3. Attach the other end of the sampling tube to a source of oxygen with a known concentration value. Initiate flow of the calibration gas at two liters per minute.
4. Allow the oxygen to saturate the sensor. While a stable value is usually observed within 30 seconds, allow at least two minutes for complete saturation.
5. If the MAXO2+ is not already ON, press the "ON" button.
6. Press the Cal button until "CAL" appears on the display (approx. 3 seconds). The analyzer will seek a stable sensor signal and good reading, then display the calibration gas.

Factors Influencing Accurate Readings

Elevation/Pressure Changes

1. Changes in elevation cause a reading error of approximately 1% per 250 feet.
2. Calibration should be performed when elevation changes by more than 500 feet.
3. This device does not automatically compensate for barometric pressure or altitude changes. Recalibrate if moved to a different altitude.

Temperature Effects

The MAXO2+ maintains calibration and reads correctly within ±3% when at thermal equilibrium within the operating temperature range. The device must be thermally stable when calibrated and allowed to stabilize after temperature changes for accurate readings.

• For best results, perform calibration at a temperature close to the analysis environment.
• Allow adequate time for the sensor to equilibrate to a new ambient temperature.

ℹ️ CAUTION: "CAL Err St" may result from a sensor not at thermal equilibrium.

Pressure Effects

Readings are proportional to the partial pressure of oxygen (concentration x absolute pressure). Readings are proportional to concentration if pressure is constant.

• Calibrate the MAXO2+ at the same pressure as the sample gas.
• If using tubing for sample gases, use the same apparatus and flow rates for calibration as for measurement.

Humidity Effects

Humidity (non-condensing) dilutes the gas, potentially reducing oxygen concentration by up to 4%. The device responds to actual oxygen concentration, not dry concentration. Avoid environments where condensation may occur, as it can obstruct the sensing surface, leading to erroneous readings and slower response times.

• Avoid usage in environments with greater than 95% relative humidity.

HELPFUL HINT: Dry the sensor by lightly shaking moisture out, or flow dry gas at two liters per minute across the sensor membrane.

Calibration Errors and Error Codes

The MAXO2+ analyzers feature self-testing to detect faulty calibrations, sensor failures, and low voltage. Listed below are error codes and possible actions:

E02: No sensor attached

• MaxO2+A: Open unit, disconnect and reconnect sensor. Unit should auto-calibrate and read 20.9%. If not, contact Maxtec Customer Service.
• MaxO2+AE: Disconnect and reconnect external sensor. Unit should auto-calibrate and read 20.9%. If not, contact Maxtec Customer Service.

E03: No valid calibration data available

• Ensure unit has reached thermal equilibrium. Press and hold the Calibration Button for three seconds to manually force a new calibration.

E04: Battery below minimum operating voltage

• Replace batteries.

CAL ERR ST: O2 Sensor reading not stable

• Wait for the displayed oxygen reading to stabilize when calibrating with 100% oxygen.
• Wait for the unit to reach thermal equilibrium (up to one hour if stored outside the specified operating temperature range).

CAL ERR LO: Sensor voltage too low

• Press and hold the Calibration Button for three seconds to manually force a new calibration. If the error repeats more than three times, contact Maxtec Customer Service.

CAL ERR HI: Sensor voltage too high

• Press and hold the Calibration Button for three seconds to manually force a new calibration. If the error repeats more than three times, contact Maxtec Customer Service.

CAL ERR BAT: Battery voltage too low to recalibrate

• Replace batteries.

Changing the Batteries

Batteries should be changed by service personnel.

• Use only brand name batteries.
• Replace with two AA batteries, observing the orientation marked on the device.

The device indicates a battery change is needed in two ways:

• The battery icon (?) on the display will flash. The unit will continue to function normally for approximately 200 hours.
• If a very low battery level is detected, error code "E04" will appear, and the unit will not function until batteries are changed.

To change batteries:

1. Remove the three screws from the back of the device using a #1 Phillips screwdriver.
2. Gently separate the two halves of the device.
3. Replace the batteries, ensuring correct polarity as indicated on the back case.

? NOTE: Incorrect battery installation will prevent contact and operation.

4. Carefully bring the two halves of the case together, ensuring wires are not pinched. The gasket will be captured on the back case half.
5. Reinsert and tighten the three screws until snug (Figure 3).

The device will automatically perform a calibration and display the % of oxygen.

HELPFUL HINT: If the unit does not function, verify screws are tight for proper electrical connection.

HELPFUL HINT: Before closing the case halves, ensure the keyed slot on the coiled cable assembly engages the tab on the back case for correct orientation and to prevent rotation, which could hinder closing and operation.

Changing the Oxygen Sensor

MAXO2+AE Model

If the oxygen sensor needs changing, the device will display "Cal Err lo".

1. Unthread the sensor from the cable by rotating the thumbscrew connector counterclockwise.
2. Pull the sensor from the connection.
3. Replace the new sensor by inserting its electrical plug into the receptacle on the oxygen sensor.
4. Rotate the thumbscrew clockwise until snug. The device will automatically calibrate and display the % of oxygen.

Cleaning and Maintenance

Store the MAXO2+ analyzer at a temperature similar to its ambient environment of daily use.

Instrument Cleaning

When cleaning or disinfecting the exterior, take care to prevent solutions from entering the instrument.

? DO NOT immerse the unit in fluids.

• Clean the surface using a mild detergent and a moist cloth.
• The MAXO2+ analyzer is not intended for steam, ethylene oxide, or radiation sterilization.

Oxygen Sensor

⚠️ WARNING: Never install the sensor where it may be exposed to patient's exhaled breath or secretions, unless disposal of the sensor, flow diverter, and tee adapter is intended after use.

• Clean the sensor with a cloth moistened with isopropyl alcohol (65% alcohol/water solution).
• Maxtec does not recommend spray disinfectants as salts can accumulate and impair readings.
• The oxygen sensor is not intended for steam, ethylene oxide, or radiation sterilization.

Accessories

The flow diverter and tee adapter may be disinfected by washing with isopropyl alcohol. Ensure parts are thoroughly dry before use.

Specifications

Base Unit Specifications

Sensor Specifications

Spare Parts and Accessories

Included With Your Unit

Optional Accessories

Optional Adapters

Mounting Options (requires dovetail R217P23)

Carrying Options

? NOTE: Repair of this equipment must be performed by a qualified service technician experienced in repair of portable hand held medical equipment.

Equipment in need of repair shall be sent to:

Maxtec, Service Department, 2305 South 1070 West, Salt Lake City, Ut 84119 (Include RMA number issued by customer service)

Electromagnetic Compatibility

Electromagnetic Emissions

This equipment is intended for use in the specified electromagnetic environment. The user should assure it is used in such an environment.

Recommended separation distances between portable and mobile RF communications equipment and the MaxO2+:

For transmitters not listed, separation distance 'd' (meters) can be estimated using the equation applicable to the transmitter's frequency, where 'P' is the maximum output power in watts (W). ? NOTE 1: At 80 MHz and 800 MHz, use the distance for the higher frequency range. ? NOTE 2: Guidelines may not apply in all situations due to absorption and reflection from structures.

Electromagnetic Immunity

This equipment is intended for use in the specified electromagnetic environment. The user should assure it is used in such an environment.

This equipment is intended for use in the specified electromagnetic environment. The customer or user should assure it is used in such an environment.