KEITHLEY 2015 THD Multimeter
Product Specifications
- Model: 2015 THD Multimeter
- Input Voltage: 350V peak, 1000V peak
- Measurement Functions: THD ACV, MATH DCV, dBm, dB, DCI, ACI
- Operating Temperature: 0-40 degrees Celsius
- Power Supply: 3A, 250V
- Warranty: Limited Warranty
Safety Precautions
Before using the 2015 THD Multimeter, please review the safety precautions provided in the manual. Only qualified personnel should operate this product to avoid injury.
User Types
- Responsible Body: Individual or group responsible for equipment use and maintenance.
- Operators: Users trained in electrical safety procedures and instrument use.
- Maintenance Personnel: Perform routine procedures to keep the product operational.
- Service Personnel: Trained to work on live circuits and perform installations and repairs.
Operating Instructions
- Ensure the multimeter is connected to a stable power source.
- Select the desired measurement function using the provided buttons.
- Connect the test leads securely to the appropriate input terminals.
- Follow the display prompts to take measurements accurately.
- After use, turn off the multimeter and disconnect it from the power source.
Frequently Asked Questions (FAQ)
Q: What should I do if the multimeter displays an error message?
A: If an error message appears, refer to the user manual for troubleshooting steps. Check the connections and ensure proper settings are selected for accurate measurements.
Q: Can the multimeter be used to measure high voltages?
A: Yes, the 2015 THD Multimeter is capable of measuring voltages up to 1000V peak. Exercise caution and follow safety guidelines when working with high voltages.
Q: How do I switch between different measurement functions?
A: Use the buttons on the multimeter interface to select the desired measurement function. Refer to the user manual for specific instructions on function selection.
Model 2015 THD Multimeter
Service Manual
SHIFT
LOCAL
POWER
REM TALK LSTN SRQ SHIFT TIMER
STEP SCAN HOLD TRIG
CH1 FAST
CH2 CH3 CH4 CH5 CH6 CH7 MED SLOW REL FILT AUTO ERR
CH8 CH9 CH10 MATH REAR
4W BUFFER STAT
SENSE 4 WIRE
INPUT
HI
350V PEAK
!
1000V PEAK
MATH DCV
THD ACV
DELAY HOLD EX TRIG TRIG
SAVE SETUP SOURCE MEAS
THD
dBm
dB
DCI ACI
LIMITS ON/OFF STORE RECALL
CONFIG HALT STEP SCAN
CONT 2 4
TEST CAL FILTER REL
GPIB RS232 DIGITS RATE
2015 THD MULTIMETER
PERIOD TCOUPL FREQ TEMP
RANGE
EXIT ENTER
AUTO RANGE
LO
INPUTS
500V PEAK
F
R
FRONT/REAR
3A 250V
AMPS
Contains Servicing Information
WARRANTY
Keithley Instruments, Inc. warrants this product to be free from defects in material and workmanship for a period of 3 years from date of shipment. Keithley Instruments, Inc. warrants the following items for 90 days from the date of shipment: probes, cables, rechargeable batteries, diskettes, and documentation. During the warranty period, we will, at our option, either repair or replace any product that proves to be defective. To exercise this warranty, write or call your local Keithley representative, or contact Keithley headquarters in Cleveland, Ohio. You will be given prompt assistance and return instructions. Send the product, transportation prepaid, to the indicated service facility. Repairs will be made and the product returned, transportation prepaid. Repaired or replaced products are warranted for the balance of the original warranty period, or at least 90 days.
LIMITATION OF WARRANTY
This warranty does not apply to defects resulting from product modification without Keithley’s express written consent, or misuse of any product or part. This warranty also does not apply to fuses, software, nonrechargeable batteries, damage from battery leakage, or problems arising from normal wear or failure to follow instructions. THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. THE REMEDIES PROVIDED HEREIN ARE BUYER’S SOLE AND EXCLUSIVE REMEDIES. NEITHER KEITHLEY INSTRUMENTS, INC. NOR ANY OF ITS EMPLOYEES SHALL BE LIABLE FOR ANY DIRECT, INDIRECT, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF ITS INSTRUMENTS AND SOFTWARE EVEN IF KEITHLEY INSTRUMENTS, INC., HAS BEEN ADVISED IN ADVANCE OF THE POSSIBILITY OF SUCH DAMAGES. SUCH EXCLUDED DAMAGES SHALL INCLUDE, BUT ARE NOT LIMITED TO: COSTS OF REMOVAL AND INSTALLATION, LOSSES SUSTAINED AS THE RESULT OF INJURY TO ANY PERSON, OR DAMAGE TO PROPERTY.
1/99
Model 2015 THD Multimeter Service Manual
©1998, Keithley Instruments, Inc. All rights reserved.
Cleveland, Ohio, U.S.A. Third Printing, June 1999 Document Number: 2015-902-01 Rev. C
Manual Print History
The print history shown below lists the printing dates of all Revisions and Addenda created for this manual. The Revision Level letter increases alphabetically as the manual undergoes subsequent updates. Addenda, which are released between Revisions, contain important change information that the user should incorporate immediately into the manual. Addenda are numbered sequentially. When a new Revision is created, all Addenda associated with the previous Revision of the manual are incorporated into the new Revision of the manual. Each new Revision includes a revised copy of this print history page.
Revision A (Document Number 2015-902-01) ……………………………………………………….. May 1998 Revision B (Document Number 2015-902-01) …………………………………………………………July 1998 Revision C (Document Number 2015-902-01) ……………………………………………………….. June 1999
All Keithley product names are trademarks or registered trademarks of Keithley Instruments, Inc. Other brand names are trademarks or registered trademarks of their respective holders.
Safety Precautions
The following safety precautions should be observed before using this product and any associated instrumentation. Although some instruments and accessories would normally be used with non-hazardous voltages, there are situations where hazardous conditions may be present.
This product is intended for use by qualified personnel who recognize shock hazards and are familiar with the safety precautions required to avoid possible injury. Read the operating information carefully before using the product.
The types of product users are:
Responsible body is the individual or group responsible for the use and maintenance of equipment, for ensuring that the equipment is operated within its specifications and operating limits, and for ensuring that operators are adequately trained.
Operators use the product for its intended function. They must be trained in electrical safety procedures and proper use of the instrument. They must be protected from electric shock and contact with hazardous live circuits.
Maintenance personnel perform routine procedures on the product to keep it operating, for example, setting the line voltage or replacing consumable materials. Maintenance procedures are described in the manual. The procedures explicitly state if the operator may perform them. Otherwise, they should be performed only by service personnel.
Service personnel are trained to work on live circuits, and perform safe installations and repairs of products. Only properly trained service personnel may perform installation and service procedures.
Exercise extreme caution when a shock hazard is present. Lethal voltage may be present on cable connector jacks or test fixtures. The American National Standards Institute (ANSI) states that a shock hazard exists when voltage levels greater than 30V RMS, 42.4V peak, or 60VDC are present. A good safety practice is to expect that hazardous voltage is present in any unknown circuit before measuring.
Users of this product must be protected from electric shock at all times. The responsible body must ensure that users are prevented access and/or insulated from every connection point. In some cases, connections must be exposed to potential human contact. Product users in these circumstances must be trained to protect themselves from the risk of electric shock. If the circuit is capable of operating at or above 1000 volts, no conductive part of the circuit may be exposed.
As described in the International Electrotechnical Commission (IEC) Standard IEC 664, digital multimeter measuring circuits (e.g., Keithley Models 175A, 199, 2000, 2001, 2002, and 2010) are Installation Category II. All other instruments’ signal terminals are Installation Category I and must not be connected to mains.
Do not connect switching cards directly to unlimited power circuits. They are intended to be used with impedance limited sources. NEVER connect switching cards directly to AC mains. When connecting sources to switching cards, install protective devices to limit fault current and voltage to the card.
Before operating an instrument, make sure the line cord is connected to a properly grounded power receptacle. Inspect the connecting cables, test leads, and jumpers for possible wear, cracks, or breaks before each use.
For maximum safety, do not touch the product, test cables, or any other instruments while power is applied to the circuit under test. ALWAYS remove power from the entire test system and discharge any capacitors before: connecting or disconnecting cables or jumpers, installing or removing switching cards, or making internal changes, such as installing or removing jumpers.
Do not touch any object that could provide a current path to the common side of the circuit under test or power line (earth) ground. Always make measurements with dry hands while standing on a dry, insulated surface capable of withstanding the voltage being measured.
The instrument and accessories must be used in accordance with its specifications and operating instructions or the safety of the equipment may be impaired.
Do not exceed the maximum signal levels of the instruments and accessories, as defined in the specifications and operating information, and as shown on the instrument or test fixture panels, or switching card.
When fuses are used in a product, replace with same type and rating for continued protection against fire hazard.
Chassis connections must only be used as shield connections for measuring circuits, NOT as safety earth ground connections.
If you are using a test fixture, keep the lid closed while power is applied to the device under test. Safe operation requires the use of a lid interlock.
If a screw is present, connect it to safety earth ground using the wire recommended in the user documentation.
The ! symbol on an instrument indicates that the user should refer to the operating instructions located in
the manual.
The symbol on an instrument shows that it can source or measure 1000 volts or more, including the combined effect of normal and common mode voltages. Use standard safety precautions to avoid personal contact with these voltages.
The WARNING heading in a manual explains dangers that might result in personal injury or death. Always read the associated information very carefully before performing the indicated procedure.
The CAUTION heading in a manual explains hazards that could damage the instrument. Such damage may invalidate the warranty.
Instrumentation and accessories shall not be connected to humans.
Before performing any maintenance, disconnect the line cord and all test cables. To maintain protection from electric shock and fire, replacement components in mains circuits, including the power transformer, test leads, and input jacks, must be purchased from Keithley Instruments. Standard fuses, with applicable national safety approvals, may be used if the rating and type are the same. Other components that are not safety related may be purchased from other suppliers as long as they are equivalent to the original component. (Note that selected parts should be purchased only through Keithley Instruments to maintain accuracy and functionality of the product.) If you are unsure about the applicability of a replacement component, call a Keithley Instruments office for information. To clean an instrument, use a damp cloth or mild, water based cleaner. Clean the exterior of the instrument only. Do not apply cleaner directly to the instrument or allow liquids to enter or spill on the instrument. Products that consist of a circuit board with no case or chassis (e.g., data acquisition board for installation into a computer) should never require cleaning if handled according to instructions. If the board becomes contaminated and operation is affected, the board should be returned to the factory for proper cleaning/servicing.
Rev. 2/99
Table of Contents
1 Performance Verification
Introduction ……………………………………………………………………………. 1-2 Verification test requirements …………………………………………………… 1-3
Environmental conditions …………………………………………………….. 1-3 Warm-up period ………………………………………………………………….. 1-3 Line power …………………………………………………………………………. 1-3 Recommended test equipment ………………………………………………….. 1-4 Verification limits ……………………………………………………………………. 1-5 Example reading limit calculation …………………………………………. 1-5 Calculating resistance reading limits ……………………………………… 1-5 Restoring factory defaults ………………………………………………………… 1-6 Performing the verification test procedures ………………………………… 1-7 Test summary ……………………………………………………………………… 1-7 Test considerations ………………………………………………………………. 1-7 Verifying DC voltage ………………………………………………………………. 1-8 Verifying AC voltage …………………………………………………………….. 1-10 Verifying DC current …………………………………………………………….. 1-12 Verifying AC current ……………………………………………………………… 1-13 Verifying resistance ………………………………………………………………. 1-14 Verifying temperature ……………………………………………………………. 1-16 Verifying frequency ………………………………………………………………. 1-17 Verifying total harmonic distortion ………………………………………….. 1-18 Verifying function generator amplitude ……………………………………. 1-19
2 Calibration
Introduction ……………………………………………………………………………. 2-2 Environmental conditions ………………………………………………………… 2-3
Warm-up period ………………………………………………………………….. 2-3 Line power …………………………………………………………………………. 2-3 Calibration considerations ……………………………………………………….. 2-4 Calibration code ……………………………………………………………………… 2-5 Front panel calibration code ………………………………………………….. 2-5 Remote calibration code ……………………………………………………….. 2-5 Comprehensive calibration ………………………………………………………. 2-6 Calibration cycle …………………………………………………………………. 2-6 Recommended equipment …………………………………………………….. 2-6 Aborting calibration …………………………………………………………….. 2-7 Front panel calibration …………………………………………………………. 2-7 Preparing the Model 2015 for calibration ……………………………….. 2-7 Front panel short and open calibration ……………………………………. 2-8 DC volts calibration …………………………………………………………….. 2-9
Resistance calibration ………………………………………………………… 2-11 DC current calibration ……………………………………………………….. 2-12 AC voltage calibration ……………………………………………………….. 2-13 AC current calibration ……………………………………………………….. 2-14 Distortion calibration …………………………………………………………. 2-14 Function generator calibration …………………………………………….. 2-15 Setting calibration dates and saving calibration …………………….. 2-16 Remote calibration …………………………………………………………….. 2-16 Preparing the Model 2015 for calibration ……………………………… 2-17 Short and open calibration ………………………………………………….. 2-17 DC volts calibration …………………………………………………………… 2-18 Resistance calibration ………………………………………………………… 2-19 DC current calibration ……………………………………………………….. 2-20 AC voltage calibration ……………………………………………………….. 2-21 AC current calibration ……………………………………………………….. 2-22 Distortion calibration …………………………………………………………. 2-22 Function generator calibration …………………………………………….. 2-23 Programming calibration dates ……………………………………………. 2-23 Saving calibration constants ……………………………………………….. 2-23 Locking out calibration ………………………………………………………. 2-23 Manufacturing calibration ……………………………………………………… 2-24 Recommended test equipment …………………………………………….. 2-24 Unlocking manufacturing calibration …………………………………… 2-24 Measuring synthesizer signal amplitude ……………………………….. 2-24 Front panel manufacturing calibration ………………………………….. 2-25 Remote manufacturing calibration ………………………………………. 2-26
3 Routine Maintenance
Introduction …………………………………………………………………………… 3-2 Setting the line voltage and replacing the line fuse ………………….. 3-2 Replacing the AMPS fuse …………………………………………………….. 3-3
4 Troubleshooting
Introduction …………………………………………………………………………… 4-2 Repair considerations ……………………………………………………………… 4-3 Power-on self-test …………………………………………………………………… 4-4 Front panel tests …………………………………………………………………….. 4-5
KEY test …………………………………………………………………………….. 4-5 DISP test ……………………………………………………………………………. 4-5 Principles of operation ……………………………………………………………. 4-6 Power supply ……………………………………………………………………… 4-6 Display board ……………………………………………………………………… 4-8 Digital circuitry …………………………………………………………………… 4-9
Analog circuitry ………………………………………………………………… 4-11 Distortion digital circuitry …………………………………………………… 4-13 Distortion analog circuitry ………………………………………………….. 4-15 Sine generator circuitry ………………………………………………………. 4-16 Troubleshooting ……………………………………………………………………. 4-18 Display board checks …………………………………………………………. 4-18 Power supply checks ………………………………………………………….. 4-19 Digital circuitry checks ………………………………………………………. 4-20 Analog signal switching states …………………………………………….. 4-21
5 Disassembly
Introduction ……………………………………………………………………………. 5-2 Handling and cleaning …………………………………………………………….. 5-3
Handling PC boards …………………………………………………………….. 5-3 Solder repairs ……………………………………………………………………… 5-3 Static sensitive devices …………………………………………………………. 5-4 Assembly drawings …………………………………………………………………. 5-5 Disassembly procedures ………………………………………………………….. 5-6 Case cover removal ……………………………………………………………… 5-6 DMM board removal ……………………………………………………………. 5-6 DSP board removal ……………………………………………………………… 5-7 Front panel disassembly ……………………………………………………….. 5-8 Removing power components ……………………………………………….. 5-8 Instrument reassembly …………………………………………………………….. 5-9 Input terminal wire connections …………………………………………….. 5-9 Power module wire connections ……………………………………………. 5-9 Changing trigger link lines …………………………………………………….. 5-10 Main CPU firmware replacement ……………………………………………. 5-11
6 Replaceable Parts
Introduction ……………………………………………………………………………. 6-2 Parts lists ……………………………………………………………………………….. 6-2 Ordering information ………………………………………………………………. 6-2 Factory service ……………………………………………………………………….. 6-2 Component layouts …………………………………………………………………. 6-2
A Specifications
Accuracy calculations …………………………………………………………….. A-9 Calculating DC characteristics accuracy ………………………………… A-9 Calculating AC characteristics accuracy ………………………………… A-9 Calculating dBm characteristics accuracy ……………………………. A-10 Calculating dB characteristics accuracy ……………………………….. A-10 Distortion characteristics ……………………………………………………. A-11
Calculating generator amplitude accuracy ……………………………. A-12 Additional derating factors ………………………………………………… A-12 Optimizing measurement accuracy ………………………………………… A-13 DC voltage, DC current, and resistance ……………………………….. A-13 AC voltage and AC current ………………………………………………… A-13 Temperature …………………………………………………………………….. A-13 Optimizing measurement speed …………………………………………….. A-14 DC voltage, DC current, and resistance ……………………………….. A-14 AC voltage and AC current ………………………………………………… A-14 Temperature …………………………………………………………………….. A-14
B Calibration Reference
Introduction ………………………………………………………………………….. B-2 Command summary ………………………………………………………………. B-3 Miscellaneous calibration commands ………………………………………. B-5
:CODE ……………………………………………………………………………… B-5 :COUNt? …………………………………………………………………………… B-5 :INIT ………………………………………………………………………………… B-6 :LOCK ……………………………………………………………………………… B-6 :LOCK? ……………………………………………………………………………. B-7 :SAVE ………………………………………………………………………………. B-7 :DATE ………………………………………………………………………………. B-8 :NDUE ……………………………………………………………………………… B-8 DC calibration commands ………………………………………………………. B-9 :STEP1 ……………………………………………………………………………… B-9 :STEP2 ……………………………………………………………………………. B-10 :STEP3 ……………………………………………………………………………. B-10 :STEP4 ……………………………………………………………………………. B-10 :STEP5 ……………………………………………………………………………. B-11 :STEP6 ……………………………………………………………………………. B-11 :STEP7 ……………………………………………………………………………. B-11 :STEP8 ……………………………………………………………………………. B-12 :STEP9 ……………………………………………………………………………. B-12 :STEP10 ………………………………………………………………………….. B-12 :STEP11 ………………………………………………………………………….. B-13 :STEP12 ………………………………………………………………………….. B-13 AC calibration commands …………………………………………………….. B-14 :AC:STEP<n> ………………………………………………………………….. B-15 Distortion and function generator calibration commands …………. B-16 :DIST:STEP1 …………………………………………………………………… B-16 :DIST:STEP2 …………………………………………………………………… B-16 :FGEN:STEP1 …………………………………………………………………. B-16
Manufacturing calibration commands …………………………………….. B-17 :AC:STEP<14|15> ……………………………………………………………. B-17 :DC:STEP0 ………………………………………………………………………. B-17
Remote error reporting …………………………………………………………. B-18 Error summary …………………………………………………………………. B-18 Error queue ………………………………………………………………………. B-20 Status byte EAV (Error Available) bit ………………………………….. B-20 Generating an SRQ on error ……………………………………………….. B-20
Detecting calibration step completion …………………………………….. B-21 Using the *OPC? query ……………………………………………………… B-21 Using the *OPC command …………………………………………………. B-21 Generating an SRQ on calibration complete …………………………. B-22
C Calibration Program
Introduction …………………………………………………………………………… C-2 Computer hardware requirements …………………………………………….. C-2 Software requirements ……………………………………………………………. C-2 Calibration equipment ……………………………………………………………. C-2 General program instructions ………………………………………………….. C-3
List of Illustrations
1 Performance Verification
Connections for DC volts verification ………………………………………. 1-8 Connections for AC volts verification ……………………………………… 1-10 Connections for DC current verification ………………………………….. 1-12 Connections for AC current verification ………………………………….. 1-13 Connections for resistance verification (100-10M range) …….. 1-14 Connections for resistance verification (100M range) …………….. 1-15 Connections for frequency verification ……………………………………. 1-17 Connections for total harmonic distortion verification ………………. 1-18 Connections for function generator amplitude verification ………… 1-19
2 Calibration
Low-thermal short connections ………………………………………………… 2-8 Connections for DC volts and ohms calibration …………………………. 2-9 Connections for DC and AC amps calibration ………………………….. 2-12 Connections for AC volts calibration ………………………………………. 2-13 Connections for distortion calibration ……………………………………… 2-15 Connections for function generator calibration …………………………. 2-15 Synthesizer connections for manufacturing calibration ……………… 2-25
3 Routine Maintenance
Power module ………………………………………………………………………… 3-3
4 Troubleshooting
Power supply block diagram ……………………………………………………. 4-6 Digital circuitry block diagram ………………………………………………… 4-8 Analog circuitry block diagram ………………………………………………. 4-11 Distortion digital circuitry block diagram ………………………………… 4-13 Distortion analog circuitry block diagram ……………………………….. 4-15 Sine generator circuitry block diagram ……………………………………. 4-16
5 Disassembly
Trigger link line connections ………………………………………………….. 5-10
List of Tables
1 Performance Verification
Recommended verification equipment ……………………………………. 1-4 DCV reading limits ……………………………………………………………… 1-9 ACV reading limits …………………………………………………………….. 1-11 DCI limits …………………………………………………………………………. 1-12 ACI limits …………………………………………………………………………. 1-13 Limits for resistance verification ………………………………………….. 1-15 Thermocouple temperature verification reading limits ……………. 1-16
2 Calibration
Recommended equipment for comprehensive calibration …………. 2-6 Comprehensive calibration procedures …………………………………… 2-8 DC volts calibration summary ……………………………………………… 2-10 Ohms calibration summary …………………………………………………. 2-11 DC current calibration summary ………………………………………….. 2-12 AC voltage calibration summary ………………………………………….. 2-13 AC current calibration summary ………………………………………….. 2-14 Distortion and function generator calibration summary ………….. 2-15 DC voltage calibration programming steps ……………………………. 2-18 Resistance calibration programming steps …………………………….. 2-19 DC current calibration programming steps ……………………………. 2-20 AC voltage calibration programming steps ……………………………. 2-21 AC current calibration programming steps ……………………………. 2-22 Distortion and function generator calibration steps ………………… 2-22 Recommended equipment for manufacturing calibration ………… 2-24
3 Routine Maintenance
Power line fuse ……………………………………………………………………. 3-3
4 Troubleshooting
Power supply components …………………………………………………….. 4-7 Display board checks …………………………………………………………. 4-18 Power supply checks ………………………………………………………….. 4-19 Digital circuitry checks ………………………………………………………. 4-20 DCV signal switching ………………………………………………………… 4-21 ACV and FREQ signal switching …………………………………………. 4-21 2 signal switching ……………………………………………………………. 4-22 4 signal switching ……………………………………………………………. 4-22 2/4 reference switching …………………………………………………. 4-22 DCA signal switching ………………………………………………………… 4-23
ACA signal switching ………………………………………………………… 4-23 DCV signal multiplexing and gain ………………………………………. 4-23 ACV and ACA signal multiplexing and gain …………………………. 4-23 DCA signal multiplexing and gain ………………………………………. 4-24 2 signal multiplexing and gain ………………………………………….. 4-24 4 signal multiplexing and gain ………………………………………….. 4-24 Switching device locations …………………………………………………… 4-25
5 Disassembly
Input terminal wire colors …………………………………………………….. 5-9 Power module wire colors …………………………………………………….. 5-9
6 Replaceable Parts
DMM (mother) board parts list ……………………………………………… 6-3 Display board parts list ………………………………………………………… 6-9 Distortion (DSP) board parts list ………………………………………….. 6-10 Mechanical parts list ………………………………………………………….. 6-14
B Calibration Reference
Remote calibration command summary ………………………………… B-3 DC calibration commands ……………………………………………………. B-9 AC calibration commands ………………………………………………….. B-14 Distortion and function generator calibration commands ……….. B-16 Calibration error summary …………………………………………………. B-18
1
Performance Verification
1-2
Performance Verification
Introduction
Use the procedures in this section to verify that Model 2015 Multimeter accuracy is within the limits stated in the instrument’s one-year accuracy specifications. You can perform these verification procedures:
· When you first receive the instrument to make sure that it was not damaged during shipment, and that the unit meets factory specifications.
· If the instrument’s accuracy is questionable. · Following calibration.
WARNING The information in this section is intended only for qualified service personnel. Do not attempt these procedures unless you are qualified to do so.
NOTE
If the instrument is still under warranty and its performance is outside specified limits, contact your Keithley representative or the factory to determine the correct course of action.
Performance Verification 1-3
Verification test requirements
Be sure that you perform the verification tests: · Under the proper environmental conditions. · After the specified warm-up period. · Using the correct line voltage. · Using the proper calibration equipment. · Using the specified reading limits.
Environmental conditions
Conduct your performance verification procedures in a test environment that has: · An ambient temperature of 18° to 28°C (65° to 82°F). · A relative humidity of less than 80% unless otherwise noted.
Warm-up period
Allow the Model 2015 Multimeter to warm up for at least one hour before conducting the verification procedures.
If the instrument has been subjected to temperature extremes (those outside the ranges stated above), allow additional time for the instrument’s internal temperature to stabilize. Typically, allow one extra hour to stabilize a unit that is 10°C (18°F) outside the specified temperature range.
Also, allow the test equipment to warm up for the minimum time specified by the manufacturer.
Line power
The Model 2015 Multimeter requires a line voltage of 100V/120V/220V/240V, ±10% and a line frequency of 45Hz to 66Hz and 360Hz to 440Hz.
1-4
Performance Verification
Recommended test equipment
Table 1-1 summarizes recommended verification equipment. You can use alternate equipment as long as that equipment has specifications at least as good as those listed in Table 1-1. Keep in mind, however, that the calibrator will add to the uncertainty of each measurement.
Table 1-1 Recommended verification equipment
Fluke 5700A Calibrator:
DC voltage
AC voltage (1kHz, 50kHz)
DC current
AC current (1kHZ)
Resistance
100mV:±14ppm 1.0V:±7ppm 10V:±5ppm 100V:±7ppm 1000V:±9ppm
100mV:±200ppm 1.0V:±82ppm 10V:±82ppm 100V:±90ppm 700V:±85ppm
10mA:±60ppm 100mA:±70ppm 1A:±110ppm 2.2A:±94ppm
1A:±690ppm 2.2A:±682ppm
100:±17ppm 1k:±12ppm 10k:±11ppm 100k:±13ppm 1M:±18ppm 10M:±37ppm 100M:±120ppm
Fluke 5725A Amplifier:
AC Voltage, 50kHz: 700V, ±375ppm
Keithley 3930A or 3940 Frequency Synthesizer:
1V RMS, 1kHz, ±5ppm
Stanford Research Systems DS-360 Ultra Low Distortion Function Generator:
1kHz, .0.95V RMS sine wave, -100dB THD
Miscellaneous Equipment:
Double banana plug to double banana plug shielded cable BNC to double banana plug shielded cable
NOTE: The Fluke 5725A amplifier is necessary only if you wish to verify the 750V AC range at 50kHz. Verification at 220V, 50kHz using only the 5700A calibrator is adequate for most applications.
Performance Verification 1-5
Verification limits
The verification limits stated in this section have been calculated using only the Model 2015 one-year accuracy specifications, and they do not include test equipment uncertainty. If a particular measurement falls slightly outside the allowable range, recalculate new limits based on both Model 2015 specifications and pertinent calibration equipment specifications.
Example reading limit calculation
The following is an example of how reading limits have been calculated: Assume you are testing the 10V DC range using a 10V input value. Using the Model 2015 one-year accuracy specification for 10V DC of ± (30ppm of reading + 5ppm of range), the calculated limits are: Reading limits = 10V ± [(10V × 30ppm) + (10V × 5ppm)] Reading limits = 10V ± (.0003 + .00005) Reading limits = 10V ± .00035V Reading limits = 9.99965V to 10.00035V
Calculating resistance reading limits
Resistance reading limits must be recalculated based on the actual calibration resistance values supplied by the equipment manufacturer. Calculations are performed in the same manner as shown in the preceding example, except, of course, that you should use the actual calibration resistance values instead of the nominal values when performing your calculations.
1-6
Performance Verification
Restoring factory defaults
Before performing the verification procedures, restore the instrument to its factory defaults as follows:
1. Press SHIFT and then SETUP. The instrument will display the following prompt: RESTORE: FACT.
2. Using either range key, select FACT, then restore the factory default conditions by pressing ENTER.
3. Factory defaults will be set as follows: Speed: medium Filter: 10 readings
Performance Verification 1-7
Performing the verification test procedures
Test summary
Verification test procedures include:
· DC volts · AC volts · DC current · AC current · Resistance · Temperature · Frequency · Total harmonic distortion · Function generator amplitude
If the Model 2015 is not within specifications and not under warranty, see the calibration procedures in Section 2.
Test considerations
When performing the verification procedures:
· Be sure to restore factory defaults as outlined above. · After restoring factory defaults and selecting the measuring function, select the SLOW
integration rate with the RATE key. · Make sure that the equipment is properly warmed up and connected to the front panel
input jacks. Also make sure that the front panel input jacks are selected with the INPUTS switch. · Do not use autoranging for any verification tests because autorange hysteresis may cause the Model 2015 to be on an incorrect range. For each test signal, you must manually set the correct range for the Model 2015 using the range keys. · Make sure the calibrator is in operate before you verify each measurement. · Always let the source signal settle before taking a reading. · Do not connect test equipment to the Model 2015 through a scanner or other switching equipment.
WARNING
The maximum common-mode voltage (voltage between INPUT LO and chassis ground) is 500V peak. Exceeding this value may cause a breakdown in insulation, creating a shock hazard. Some of the procedures in this section may expose you to dangerous voltages. Use standard safety precautions when such dangerous voltages are encountered to avoid personal injury caused by electric shock.
1-8
Performance Verification
Verifying DC voltage
Check DC voltage accuracy by applying accurate voltages from the DC voltage calibrator to the Model 2015 INPUT jacks and verifying that the displayed readings fall within specified limits.
CAUTION Do not exceed 1100V peak between INPUT HI and INPUT LO because instrument damage may occur.
Follow these steps to verify DC voltage accuracy:
1. Connect the Model 2015 HI and LO INPUT jacks to the DC voltage calibrator as shown in Figure 1-1.
NOTE
Use shielded, low-thermal connections when testing the 100mV and 1V ranges to avoid errors caused by noise or thermal effects. Connect the shield to the calibrator’s output LO terminal.
Figure 1-1 Connections for DC volts verification
Model 2015
SHIFT
LOCAL
POWER
REM TALK LSTN SRQ SHIFT TIMER
STEP SCAN HOLD TRIG
CH1 FAST
CH2 CH3 CH4 CH5 CH6 CH7 MED SLOW REL FILT AUTO ERR
CH8 CH9 CH10 MATH REAR
4W BUFFER STAT
SENSE 4 WIRE
INPUT
HI
350V PEAK
!
1000V PEAK
MATH DCV
THD ACV
DELAY HOLD EX TRIG TRIG
SAVE SETUP SOURCE MEAS
TH D
dBm
dB
DCI ACI
LIMITS ON/OFF STORE RECALL
CONFIG HALT STEP SCAN
CONT 2 4
TEST CAL FILTER REL
GPIB RS232 DIGITS RATE
2015 THD MULTIMETER
PERIOD TCOUPL FREQ TEMP
RANGE
EXIT ENTER
AUTO RANGE
LO INPUTS
500V PEAK
F
R
FRONT/REAR
3A 250V AMPS
Input HI Output HI
Input LO
O utput LO
DC Voltage Calibrator
Note: Use shielded, low-thermal cables for 100mV and 1V ranges.
Performance Verification 1-9
2. Select the DC volts function by pressing the DCV key, and set the Model 2015 to the 100mV range. Select the SLOW integration rate with the RATE key.
3. Set the calibrator output to 0.00000mV DC, and allow the reading to settle. 4. Enable the Model 2015 REL mode. Leave REL enabled for the remainder of the DC
volts verification tests. 5. Source positive and negative and full-scale voltages for each of the ranges listed in
Table 1-2. For each voltage setting, be sure that the reading is within stated limits.
Table 1-2 DCV reading limits
Range
Applied DC voltage* Reading limits (1 year, 18°-28°C)
100mV 1V 10V 100V 1000V
100.0000mV 1.000000V 10.00000V 100.0000V 1000.000V
99.9915 to 100.0085mV 0.999963 to 1.000037V 9.99965 to 10.00035V 99.9949 to 100.0051V 999.949 to 1000.051V
* Source positive and negative values for each range.
1-10 Performance Verification
Verifying AC voltage
Check AC voltage accuracy by applying accurate AC voltages at specific frequencies from the AC voltage calibrator to the Model 2015 inputs and verifying that the displayed readings fall within specified ranges.
CAUTION Do not exceed 1100 V peak between INPUT HI and INPUT LO, or 8 × 107 V· Hz input, because instrument damage may occur.
Follow these steps to verify AC voltage accuracy:
1. Connect the Model 2015 HI and LO INPUT jacks to the AC voltage calibrator as shown in Figure 1-2.
Figure 1-2 Connections for AC volts verification
Note: Amplifier required only for 700V, 50kHz output.
AC Voltage Amplifier
Model 2015
Input HI
SHIFT
LOCAL
POWER
REM STEP SCAN TALK LSTN SRQ SHIFT TIMER HOLD TRIG
CH1 FAST
CH2 CH3 CH4 MED SLOW REL
CH5 CH6 FILT AUTO
CH7 ERR
CH8 CH9 CH10 MATH REAR
4W BUFFER STAT
SENSE 4 WIRE
INPUT
HI
350V PEAK
!
1000V PEAK
MATH DCV
THD ACV
DELAY HOLD EX TRIG TRIG
SAVE SETUP SOURCE MEAS
TH D
dBm
dB
DCI ACI
LIMITS ON/OFF STORE RECALL
CONFIG HALT STEP SCAN
CONT 2 4
TEST CAL FILTER REL
GPIB RS232 DIGITS RATE
2015 THD MULTIMETER
PERIOD TCOUPL
FREQ TEMP
RANGE
AUTO RANGE
EXIT ENTER
LO INPUTS
500V PEAK
F
R
FRONT/REAR
3A 250V AMPS
Output HI
Input LO
O utput Shielded cable LO
AC Voltage Calibrator
Performance Verification 1-11
2. Select the AC volts function by pressing the ACV key, then choose the SLOW integration rate with the RATE key.
3. Set the Model 2015 for the 100mV range; make sure that REL is disabled. 4. Source 1kHz and 50kHz AC voltages for each of the ranges summarized in Table
1-3, and make sure that the respective Model 2015 readings fall within stated limits.
Table 1-3 ACV reading limits
ACV range
Applied AC voltage
1kHz reading limits (1 year, 18°C-28°C)
50kHz reading limits (1 year, 18°C-28°C)
100mV 1V 10V 100V 750V
100.0000mV 1.000000V 10.00000V 100.0000V 700.000V*
99.910 to 100.090mV 0.99910 to 1.00090V 9.9910 to 10.0090V 99.910 to 100.090V 699.36 to 700.64V
99.830 to 100.170mV 0.99830 to 1.00170V 9.98300 to 10.0170V 99.830 to 100.170V 698.79 to 701.21V
* If the 5725A amplifier is not available, change the 700V @ 50kHz step to 220V @ 50kHz. Reading limits for 220V @ 50kHz = 219.36 to 220.64V.
1-12 Performance Verification
Verifying DC current
Check DC current accuracy by applying accurate DC currents from the DC current calibrator to the AMPS input of the Model 2015 and verifying that the displayed readings fall within specified limits.
Follow these steps to verify DC current accuracy:
1. Connect the Model 2015 AMPS and INPUT LO jacks to the calibrator as shown in Figure 1-3.
Figure 1-3 Connections for DC current verification
Model 2015
SHIFT
LOCAL
POWER
REM STEP SCAN TALK LSTN SRQ SHIFT TIMER HOLD TRIG
CH1 FAST
CH2 CH3 CH4 MED SLOW REL
CH5 CH6 FILT AUTO
CH7 ERR
CH8 CH9 CH10 MATH REAR
4W BUFFER STAT
SENSE 4 WIRE
INPUT
HI
350V PEAK
!
1000V PEAK
MATH DCV
THD ACV
DELAY HOLD EX TRIG TRIG
SAVE SETUP SOURCE MEAS
TH D
dBm
dB
DCI ACI
LIMITS ON/OFF STORE RECALL
CONFIG HALT STEP SCAN
CONT 2 4
TEST CAL FILTER REL
GPIB RS232 DIGITS RATE
2015 THD MULTIMETER
PERIOD TCOUPL FREQ TEMP
RANGE
EXIT ENTER
AUTO RANGE
LO INPUTS
500V PEAK
F
R
FRONT/REAR
3A 250V AMPS
Input LO
Output HI
DC Current Calibrator
Amps
O utput LO
Note: Be sure calibrator is set for normal current output.
2. Select the DC current measurement function by pressing the DCI key, then choose the SLOW integration rate with the RATE key.
3. Set the Model 2015 for the 10mA range. 4. Source positive and negative full-scale currents for each of the ranges listed in Table
1-4, and verify that the readings for each range are within stated limits.
Table 1-4 DCI limits
DCI range
Applied DC current* Reading limits (1 year, 18°C-28°C)
10mA 100mA 1A 3A
10.0000mA 100.0000mA 1.000000A 2.20000A
9.99460 to 10.00540mA 99.9100 to 100.0900mA 0.999160 to 1.000840A 2.197315 to 2.202685A
*Source positive and negative currents with values shown.
Performance Verification 1-13
Verifying AC current
Check AC current accuracy by applying accurate AC voltage current at specific frequencies from the AC current calibrator to the Model 2015 input and verifying that the displayed readings fall within specified limits. Follow these steps to verify AC current:
1. Connect the Model 2015 AMPS and INPUT LO jacks to the calibrator as shown in Figure 1-4.
Figure 1-4 Connections for AC current verification
Model 2015
SHIFT
LOCAL
POWER
REM STEP SCAN TALK LSTN SRQ SHIFT TIMER HOLD TRIG
CH1 FAST
CH2 CH3 MED SLOW
CH4 REL
CH5 CH6 FILT AUTO
CH7 ERR
CH8 CH9 CH10 MATH REAR
4W BUFFER STAT
SENSE 4 WIRE
INPUT
HI
350V PEAK
!
1000V PEAK
MATH DCV
THD ACV
DELAY HOLD EX TRIG TRIG
SAVE SETUP SOURCE MEAS
TH D
dBm
dB
DCI ACI
LIMITS ON/OFF STORE RECALL
CONFIG HALT STEP SCAN
CONT 2 4
TEST CAL FILTER REL
GPIB RS232 DIGITS RATE
2015 THD MULTIMETER
PERIOD TCOUPL FREQ TEMP
RANGE
EXIT ENTER
AUTO RANGE
LO INPUTS
500V PEAK
F
R
FRONT/REAR
3A 250V AMPS
Amps
Output HI
Input LO
O utput LO
AC Current Calibrator
2. Select the AC current function by pressing the ACI key, then choose the SLOW integration rate with the RATE key.
3. Set the Model 2015 for the 1A range.
4. Source 1A and 2.2A, 1kHz full-scale AC currents as summarized in Table 1-5, and verify that the readings are within stated limits.
Table 1-5 ACI limits
ACV range
1A 3A
Applied AC voltage
1.000000A 2.20000A
Reading limits @ 1kHz (1 year, 18°C-28°C)
0.99860 to 1.00140A 2.1949 to 2.2051A
1-14 Performance Verification
Verifying resistance
Check resistance by connecting accurate resistance values to the Model 2015 and verifying that its resistance readings are within the specified limits.
CAUTION
Do not apply more than 1100V peak between INPUT HI and LO or more than 350V peak between SENSE HI and LO, or instrument damage could occur.
Follow these steps to verify resistance accuracy:
1. Using shielded 4-wire connections, connect the Model 2015 INPUT and SENSE jacks to the calibrator as shown in Figure 1-5.
Figure 1-5 Connections for resistance verification (100-10M ranges)
Model 2015
Sense HI
SHIFT
LOCAL
POWER
REM STEP SCAN TALK LSTN SRQ SHIFT TIMER HOLD TRIG
CH1 FAST
CH2 CH3 CH4 MED SLOW REL
CH5 CH6 FILT AUTO
CH7 ERR
CH8 CH9 CH10 MATH REAR
4W BUFFER STAT
SENSE 4 WIRE
INPUT
HI
350V PEAK
!
1000V PEAK
MATH DCV
THD ACV
DELAY HOLD EX TRIG TRIG
SAVE SETUP SOURCE MEAS
TH D
dBm
dB
DCI ACI
LIMITS ON/OFF STORE RECALL
CONFIG HALT STEP SCAN
CONT 2 4
TEST CAL FILTER REL
GPIB RS232 DIGITS RATE
2015 THD MULTIMETER
PERIOD TCOUPL
FREQ TEMP
RANGE
AUTO RANGE
EXIT ENTER
LO INPUTS
500V PEAK
F
R
FRONT/REAR
3A 250V AMPS
Sense HI
Input HI
O utput HI
Input Output LO LO
Resistance Calibrator
Sense LO
Sense LO
Note: Use shielded low-thermal cables to minimize noise. Enable or disable calibrator external sense as indicated in procedure.
2. Set the calibrator for 4-wire resistance with external sense on. 3. Select the Model 2015 4-wire resistance function by pressing the 4 key, then choose
the SLOW integration rate with the RATE key. 4. Set the Model 2015 for the 100 range, and make sure the FILTER is on. 5. Recalculate reading limits based on actual calibrator resistance values.
Performance Verification 1-15
6. Source the nominal full-scale resistance values for the 100-10M ranges summarized in Table 1-6, and verify that the readings are within calculated limits.
7. Connect the Model 2015 INPUT and SENSE jacks to the calibrator as shown in Figure 1-6.
8. Disable external sense on the calibrator.
9. Set the Model 2015 for the 100M range. 10. Source a nominal 100M resistance value, and verify that the reading is within cal-
culated limits for the 100M range.
Figure 1-6 Connections for resistance verification (100M range)
Model 2015
Sense HI
SHIFT
LOCAL
POWER
REM TALK LSTN SRQ SHIFT TIMER
STEP SCAN HOLD TRIG
CH1 FAST
CH2 CH3 CH4 CH5 CH6 CH7 MED SLOW REL FILT AUTO ERR
CH8 CH9 CH10 MATH REAR
4W BUFFER STAT
SENSE 4 WIRE
INPUT
HI
350V PEAK
!
1000V PEAK
MATH DCV
THD ACV
DELAY HOLD EX TRIG TRIG
SAVE SETUP SOURCE MEAS
TH D
dBm
dB
DCI ACI
LIMITS ON/OFF STORE RECALL
CONFIG HALT STEP SCAN
CONT 2 4
TEST CAL FILTER REL
GPIB RS232 DIGITS RATE
2015 THD MULTIMETER
PERIOD TCOUPL FREQ TEMP
RANGE
EXIT ENTER
AUTO RANGE
LO INPUTS
500V PEAK
F
R
FRONT/REAR
3A 250V AMPS
Input HI
O utput HI
Input Output LO LO
Resistance Calibrator
Sense LO
Note: Use shielded cables to minimize noise. Disable calibrator external sense mode.
Table 1-6 Limits for resistance verification
Range
Nominal resistance
Nominal reading limits (1 year, 18°C-28°C)
Recalculated limits*
100 1k 10k 100k 1M 10M 100M
100 1k 10k 100k 1M 10M 100M
99.9860 to 100.0140 0.999890 to 1.000110k 9.99890 to 10.00110k 99.9890 to 100.0110k 0.999890 to 1.000110M 9.99590 to 10.00410M 99.8470 to 100.1530M
__________ to __________ __________ to __________ k __________ to __________ k __________ to __________ k __________ to __________ M __________ to __________ M __________ to __________ M
* Calculate limits based on actual calibration resistance values and Model 2015 one-year accuracy specifications. See Verification limits.
1-16 Performance Verification
Verifying temperature
Thermocouple temperature readings are derived from DC volts measurements. For that reason, it is not necessary to independently verify the accuracy of temperature measurements. As long as the DC volts function meets or exceed its specifications, temperature function accuracy is automatically verified. However, temperature verification procedures are provided below for those who wish to separately verify temperature accuracy.
1. Connect the DC voltage calibrator output terminals to the Model 2015 INPUT jacks using low-thermal shielded connections. (Use 2-wire connections similar to those shown in Figure 1-1.)
2. Configure the Model 2015 for °C units, type J temperature sensor, and 0°C simulated reference junction as follows: A. Press SHIFT then SENSOR, and note the unit displays the temperature units: UNITS: C. (If necessary, use the cursor and range keys to select °C units.) B. Press ENTER. The unit then displays the thermocouple type: TYPE: J. C. Select a type J temperature sensor, then press ENTER. The unit then displays the reference junction type: JUNC: SIM. D. Make certain that the simulated reference junction type is selected, then press ENTER. The unit then displays the current simulated reference junction temperature: SIM: 023. E. Using the cursor and range keys, set the reference junction temperature to 0°C, then press ENTER to complete the temperature configuration process.
3. Select the temperature function by pressing the TEMP key. 4. Source each of the voltages summarized in Table 1-7, and verify that the tempera-
ture readings are within limits. Be sure to select the appropriate thermocouple type for each group of readings. (See step 2 above.)
Table 1-7 Thermocouple temperature verification reading limits
Thermocouple type
J
Applied DC voltage*
-7.659mV 0mV 42.280mV
Reading limits (1 year, 18°C-28°C)
-190.6 to -189.4°C -0.5 to +0.5°C 749.5 to 750.5°C
K
-5.730mV
-190.6 to -189.4°C
0mV
-0.5 to +0.5°C
54.138mV
1349.2 to 1350.8°C
* Voltages shown are based on ITS-90 standard using 0°C reference junction temperature. See text for procedure to set reference junction temperature.
Performance Verification 1-17
Verifying frequency
Follow the steps below to verify the Model 2015 frequency function:
1. Connect the frequency synthesizer to the Model 2015 INPUT jacks. (See Figure 1-7.) 2. Set the synthesizer to output a 1kHz, 1V RMS sine wave. 3. Select the Model 2015 frequency function by pressing the FREQ key. 4. Verify that the Model 2015 frequency reading is between 0.9999kHz and 1.0001kHz. Figure 1-7 Connections for frequency verification
Model 2015
BN C-to-D ual Banana Plug
Adapter
SHIFT
LOCAL
POWER
REM STEP SCAN TALK LSTN SRQ SHIFT TIMER HOLD TRIG
CH1 FAST
CH2 CH3 CH4 MED SLOW REL
CH5 CH6 FILT AUTO
CH7 ERR
CH8 CH9 CH10 MATH REAR
4W BUFFER STAT
SENSE 4 WIRE
INPUT
HI
350V PEAK
!
1000V PEAK
MATH DCV
THD ACV
DELAY HOLD EX TRIG TRIG
SAVE SETUP SOURCE MEAS
TH D
dBm
dB
DCI ACI
LIMITS ON/OFF STORE RECALL
CONFIG HALT STEP SCAN
CONT 2 4
TEST CAL FILTER REL
GPIB RS232 DIGITS RATE
2015 THD MULTIMETER
PERIOD TCOUPL FREQ TEMP
RANGE
EXIT ENTER
AUTO RANGE
LO INPUTS
500V PEAK
F
R
FRONT/REAR
3A 250V AMPS
Frequency Synthesizer
M ai n Function O utput
50 BNC Coaxial Cable
1-18 Performance Verification
Verifying total harmonic distortion
Follow the steps below to verify the Model 2015 total harmonic distortion function.
1. Connect the low-distortion function generator to the Model 2015 INPUT jacks. (See Figure 1-8.)
Figure 1-8 Connections for total harmonic distortion verification
Model 2015
BN C-to-D ual Banana Plug
Adapter
SHIFT
LOCAL
POWER
REM STEP SCAN TALK LSTN SRQ SHIFT TIMER HOLD TRIG
CH1 FAST
CH2 CH3 CH4 CH5 CH6 CH7 MED SLOW REL FILT AUTO ERR
CH8 CH9 CH10 MATH REAR
4W BUFFER STAT
SENSE 4 WIRE
INPUT
HI
350V PEAK
!
1000V PEAK
MATH DCV
THD ACV
DELAY HOLD EX TRIG TRIG
SAVE SETUP SOURCE MEAS
TH D
dBm
dB
DCI ACI
LIMITS ON/OFF STORE RECALL
CONFIG HALT STEP SCAN
CONT 2 4
TEST CAL FILTER REL
GPIB RS232 DIGITS RATE
2015THD MULTIMETER
PERIOD TCOUPL FREQ TEMP
RANGE
EXIT ENTER
AUTO RANGE
LO INPUTS
500V PEAK
F
R
FRONT/REAR
3A 250V AMPS
Low Distortion Function Generator O utput
Coaxial Cable
2. Set the function generator to output a 1kHz, 0.95V RMS sine wave with an unbalanced, high-impedance output.
3. Using the MEAS key, set the following operating modes: TYPE: THD FREQ: AUTO UPR HARM: 10 UNITS: PERC SFIL: NONE
4. Select the Model 2015 THD function by pressing SHIFT then THD. 5. Use the down RANGE key to select the 1V range. 6. Verify that the Model 2015 THD reading is <0.004%.
Performance Verification 1-19
Verifying function generator amplitude
Follow the steps below to verify Model 2015 function generator amplitude:
1. Connect the rear panel SOURCE OUTPUT jack to the front panel INPUT jacks. (See Figure 1-9.)
Figure 1-9 Connections for function generator amplitude verification
Model 2015
SHIFT
LOCAL
POWER
REM TALK LSTN SRQ SHIFT TIMER
STEP SCAN HOLD TRIG
CH1 FAST
CH2 CH3 CH4 CH5 CH6 CH7 MED SLOW REL FILT AUTO ERR
CH8 CH9 CH10 MATH REAR
4W BUFFER STAT
SENSE 4 WIRE
INPUT
HI
350V PEAK
!
1000V PEAK
MATH DCV
THD ACV
DELAY HOLD EX TRIG TRIG
SAVE SETUP SOURCE MEAS
TH D
dBm
dB
DCI ACI
LIMITS ON/OFF STORE RECALL
CONFIG HALT STEP SCAN
CONT 2 4
TEST CAL FILTER REL
GPIB RS232 DIGITS RATE
2015 THD MULTIMETER
PERIOD TCOUPL
FREQ TEMP
RANGE
AUTO RANGE
EXIT ENTER
LO INPUTS
500V PEAK
F
R
FRONT/REAR
3A 250V AMPS
Connect INPUT jacks to rear panel SOURCE OUTPUT
2. Use the SOURCE key to set the function generator operating modes as follows: SINE OUT: ON FREQ: 1kHz IMPEDANCE: HIZ AMPL: 4.0000V
3. Press the ACV key to select the AC voltage function, and choose the 10V range. 4. Verify that the AC voltage reading is between 3.986V and 4.014V.
2
Calibration
2-2
Calibration
Introduction
Use the procedures in this section to calibrate the Model 2015. Calibration procedures include:
· Comprehensive calibration: Usually the only calibration required in the field. · Manufacturing calibration: Usually only performed at the factory (unless the unit has
been repaired).
WARNING This information in this section is intended only for qualified service personnel. Do not attempt these procedures unless you are qualified to do so.
All the procedures require accurate calibration equipment to supply precise DC and AC voltages, DC and AC currents, and resistance values. Comprehensive AC, DC, distortion, or function generator calibration can be performed any time by an operator either from the front panel, or by using the SCPI commands sent either over the IEEE-488 bus or the RS-232 port. DC-only, distortion, and function generator calibration may be performed individually, if desired.
Calibration
2-3
Environmental conditions
Conduct the calibration procedures in a location that has: · An ambient temperature of 18° to 28°C (65° to 82°F) · A relative humidity of less than 80% unless otherwise noted
Warm-up period
Allow the Model 2015 Multimeter to warm up for at least one hour before performing calibration.
If the instrument has been subjected to temperature extremes (those outside the ranges stated in the above section) allow extra time for the instrument’s internal temperature to stabilize. Typically, allow one extra hour to stabilize a unit that is 10°C (18°F) outside the specified temperature range.
Also, allow the test equipment to warm up for the minimum time specified by the manufacturer.
Line power
The Model 2015 Multimeter requires a line voltage of 100V/120V/220V/240V, ±10% and a line frequency of 45Hz to 66Hz, or 360Hz to 440Hz.
2-4
Calibration
Calibration considerations
When performing the calibration procedures:
· Make sure that the equipment is properly warmed up and connected to the appropriate input jacks. Also make sure that the correct input jacks are selected with the INPUTS switch.
· Make sure the calibrator is in operate before you complete each calibration step.
· Always let the source signal settle before calibrating each point.
· Do not connect test equipment to the Model 2015 through a scanner or other switching equipment.
· If an error occurs during calibration, the Model 2015 will generate an appropriate error message. See Appendix B for more information.
WARNING
The maximum common-mode voltage (voltage between INPUT LO and chassis ground) is 500 V peak. Exceeding this value may cause a breakdown in insulation, creating a shock hazard. Some of the procedures in this section may expose you to dangerous voltages. Use standard safety precautions when such dangerous voltages are encountered to avoid personal injury caused by electric shock.
CAUTION
Do not exceed 1100V peak between INPUT HI and INPUT LO or 350V peak between SENSE HI and SENSE LO. Exceeding these values may result in instrument damage.
Calibration
2-5
Calibration code
Before performing comprehensive calibration, you must first unlock calibration by entering the appropriate calibration code.
Front panel calibration code
For front panel calibration, follow these steps:
1. Access the calibration menu by pressing SHIFT CAL, and note that the instrument displays the following: CAL: DATES
2. Use the up or down range key to scroll through the available calibration parameters until the unit displays RUN, then press ENTER.
3. The Model 2015 then prompts you to enter a code: CODE? 000000 (The factory default code is 002015.) Use the left and right arrow keys to move among the digits; use the up range key to increment numbers, and press the down range key to specify alphabetic letters. Confirm the code by pressing ENTER.
4. The Model 2015 allows you to define a new calibration code. Use the up and down range keys to toggle between yes and no. Choose N if you do not want to change the code. Choose Y if you want to change the code. The unit then prompts you to enter a new code. Enter the code, and press ENTER.
Remote calibration code
If you are performing calibration over the IEEE-488 bus or the RS-232 port, send this command to unlock calibration:
:CAL:PROT:CODE ‘<8-character string>’.
The default code command is:
:CAL:PROT:CODE ‘KI002015’.
2-6
Calibration
Comprehensive calibration
The comprehensive calibration procedure calibrates the DCV, DCI, ACV, ACI, ohms, and generator functions You can also choose to calibrate only the DCV/DCI and resistance, ACV/ ACI, distortion, or generator functions.
These procedures are usually the only ones required in the field. Manufacturing calibration is normally done only at the factory, but it should also be done in the field if the unit has been repaired. See Manufacturing calibration at the end of this section for more information.
Calibration cycle
Perform comprehensive calibration at least once a year, or every 90 days to ensure the unit meets the corresponding specifications.
Recommended equipment
Table 2-1 lists the recommended equipment you need for comprehensive, DC only, AC only, distortion, and generator calibration procedures. You can use alternate equipment, such as a DC transfer standard and characterized resistors, as long that equipment has specifications at least as good as those listed in the table.
Table 2-1 Recommended equipment for comprehensive calibration
Fluke 5700A Calibrator:
DC voltage
AC voltage (1kHz, 50kHz)*
DC current
AC current (1kHz)
Resistance
10V:±5ppm 100V: ±ppm
10mV:±710ppm 100mV:±200ppm 1V:±82ppm 10V:±82ppm 100V:±90ppm 700V:±85ppm
10mA:±60ppm 100mA:±70ppm 1A:±110ppm
100mA:±190ppm 1A:±690ppm 2A:±670ppm
1k:±12ppm 10k:±11ppm 100k:±13ppm 1M:±18ppm
Stanford Research Systems DS-360 Ultra Low Distortion Function Generator:
1V RMS sine wave @ 137Hz, -100dB THD 1V RMS sine wave @ 844Hz, -100dB THD
Miscellaneous equipment:
Keithley 8610 low-thermal shorting plug Double banana plug to double banana plug shielded cable BNC to double banana plug shielded cable
* 1kHz specifications. 10mV and 700V points require 1kHz only. All calibrator specifications are 90-day, 23°C ±5°C specifications and indicate total absolute uncertainty at specified output.
Calibration
2-7
Aborting calibration
You can abort the front panel calibration process at any time by pressing EXIT. The instrument will then ask you to confirm your decision to abort with the following message:
ABORT CAL?
Press EXIT to abort calibration at this point, or press any other key to return to the calibration process.
NOTE The Model 2015 will not respond to any remote programming commands while the ABORT CAL? message is displayed.
Front panel calibration
Follow the steps in the following paragraphs for comprehensive, DC only, AC only, distortion, and function generator calibration procedures.
The procedures for front panel calibration include:
· Preparing the Model 2015 for calibration · Front panel short and open calibration · DC voltage calibration · Resistance calibration · DC current calibration · AC voltage calibration · AC current calibration · Distortion calibration · Function generator calibration · Setting calibration dates
Preparing the Model 2015 for calibration
1. Turn on the Model 2015, and allow it to warm up for at least one hour before performing calibration procedure.
2. Select the DCV function, and choose SLOW as the RATE (integration time = 10 PLC). 3. Start the calibration process as follows:
A. Access the calibration menu by pressing SHIFT then CAL. B. Use the up and down range keys to scroll through the available calibration menu
items until the unit displays RUN, then press ENTER. C. At the prompt, enter the calibration code. (The default code is 002015.) Use the left
and right arrow keys to move among the digits; use the up range key to increment numbers, and press the down range key to specify alphabetic letters. Confirm the code by pressing ENTER. D. Choose N at the prompt to proceed without changing the code, then press ENTER.
2-8
Calibration
4. Choose which of the calibration tests summarized in Table 2-2 you want to run at the CAL: RUN prompt. Use the up and down range keys to scroll through the options; select your choice by pressing ENTER.
Table 2-2 Comprehensive calibration procedures
Procedure
Menu choice Procedures
Full calibration DCV, DCI, and ohms ACV and ACI Distortion Function generator*
ALL DC AC DIST FGEN
All comprehensive calibration steps. (DC, AC, DIST, FGEN) DC voltage, DC current, and resistance calibration. AC voltage and AC current. Calibrate distortion. Calibrate function generator.
*Perform AC calibration first if distortion or function generator calibration is done separately.
Front panel short and open calibration
At the Model 2015 prompt for a front panel short, do the following:
1. Connect the Model 8610 low-thermal short to the instrument front panel INPUT and SENSE terminals as shown in Figure 2-1. Make sure the INPUTS button is not pressed in so that the front inputs are selected. Wait at least three minutes before proceeding to allow for thermal equilibrium.
Figure 2-1 Low-thermal short connections
Model 2015
S+
HI
SHIFT
LOCAL
POWER
REM TALK LSTN SRQ SHIFT TIMER
STEP SCAN HOLD TRIG
CH1 FAST
CH2 CH3 CH4 CH5 CH6 CH7 MED SLOW REL FILT AUTO ERR
CH8 CH9 CH10 MATH REAR
4W BUFFER STAT
SENSE 4 WIRE
INPUT
HI
350V PEAK
!
1000V PEAK
MATH DCV
THD ACV
DELAY HOLD EX TRIG TRIG
SAVE SETUP SOURCE MEAS
TH D
dBm
dB
DCI ACI
LIMITS ON/OFF STORE RECALL
CONFIG HALT STEP SCAN
CONT 2 4
TEST CAL FILTER REL
GPIB RS232 DIGITS RATE
2015 THD MULTIMETER
PERIOD TCOUPL
FREQ TEMP
RANGE
EXIT ENTER
AUTO RANGE
LO INPUTS
500V PEAK
F
R
FRONT/REAR
3A 250V AMPS
Model 8610 Low -thermal
short
S-
LO
NOTE
Be sure to connect the low-thermal short properly to the HI, LO, and SENSE terminals. Keep drafts away from low-thermal connections to avoid thermal drift, which could affect calibration accuracy.
Calibration
2-9
2. Press ENTER to start short-circuit calibration. While the unit is calibrating, it will display: CALIBRATING
3. When the unit is done calibrating, it will display the following prompt: OPEN CIRCUIT
4. Remove the calibration short, and press ENTER. During this phase, the CALIBRATING message will be displayed.
DC voltscalibration
After the front panel short and open procedure, the unit will prompt you for the first DC voltage: +10V. Do the following:
1. Connect the calibrator to the Model 2015 as shown in Figure 2-2. Wait three minutes to allow for thermal equilibrium before proceeding.
Figure 2-2 Connections for DC volts and ohms calibration
Model 2015
Sense HI
SHIFT
LOCAL
POWER
REM STEP SCAN TALK LSTN SRQ SHIFT TIMER HOLD TRIG
CH1 FAST
CH2 CH3 CH4 CH5 CH6 CH7 MED SLOW REL FILT AUTO ERR
CH8 CH9 CH10 MATH REAR
4W BUFFER STAT
SENSE 4 WIRE
INPUT
HI
350V PEAK
!
1000V PEAK
MATH DCV
THD ACV
DELAY HOLD EX TRIG TRIG
SAVE SETUP SOURCE MEAS
TH D
dBm
dB
DCI ACI
LIMITS ON/OFF STORE RECALL
CONFIG HALT STEP SCAN
CONT 2 4
TEST CAL FILTER REL
GPIB RS232 DIGITS RATE
2015 THD MULTIMETER
PERIOD TCOUPL
FREQ TEMP
RANGE
AUTO RANGE
EXIT ENTER
LO INPUTS
500V PEAK
F
R
FRONT/REAR
3A 250V AMPS
Sense LO
Sense HI
DC Voltage Calibrator
Input HI
O utput HI
Input Output LO LO
Sense LO
Note: Use shielded low-thermal cables to minimize noise. Enable or disable calibrator external sense as indicated in procedure.
NOTE
Although 4-wire connections are shown, the sense leads are connected and disconnected at various points in this procedure by turning calibrator external sense on or off as appropriate. If your calibrator does not have provisions for turning external sense on and off, disconnect the sense leads when external sensing is to be turned off, and connect the sense leads when external sensing is to be turned on.
2. Set the calibrator to output DC volts, and turn external sense off.
2-10 Calibration
3. Perform the steps listed in Table 2-3 to complete DC volts calibration. For each calibration step:
· Set the calibrator to the indicated value, and make sure it is in operate. · Press the ENTER key to calibrate that step. · Wait until the Model 2015 finishes each step. (The unit will display the CALI-
BRATING message while calibrating.)
NOTE
If your calibrator cannot output the values recommended in Table 2-3, use the left and right arrow keys, and the up and down range keys to set the Model 2015 display value to match the calibrator output voltage.
Table 2-3 DC volts calibration summary
Calibration Calibrator
step
voltage
+10V -10V 100V
+10.00000V -10.00000V +100.0000V
Allowable range
+9V to +11V -9V to -11V +90V to +110V
Calibration
2-11
Resistance calibration
Completing the 100V DC calibration step ends the DC voltage calibration procedure. The Model 2015 will then prompt you to connect 1k. Follow these steps for resistance calibration:
1. Set the calibrator output for resistance, and turn on external sense.
NOTE Use external sense (4-wire ) when calibrating all resistance ranges. Be sure that the calibrator external sense mode is turned on.
2. Perform the calibration steps summarized in Table 2-4. For each step:
· Set the calibrator to the indicated value, and place the unit in operate. (If the calibrator cannot output the exact resistance value, use the Model 2015 left and right arrow keys and the range keys to adjust the Model 2015 display to agree with the calibrator resistance.)
· Press the ENTER key to calibrate each point. · Wait for the Model 2015 to complete each step before continuing.
Table 2-4 Ohms calibration summary
Calibration Calibrator
step
resistance*
Allowable range
1k 10k 100k 1M
1k 10k 100k 1M
0.9k to 1.1k 9k to 11k 90k to 110k 0.9M to 1.1M
* Nominal resistance. Adjust Model 2015 calibration parameter to agree with actual value.
2-12 Calibration
DC current calibration
After the 1M resistance point has been calibrated, the unit will prompt you for 10mA. Follow these steps for DC current calibration:
1. Connect the calibrator to the AMPS and INPUT LO terminals of the Model 2015 as shown in Figure 2-3.
Figure 2-3 Connections for DC and AC amps calibration
Model 2015
SHIFT
LOCAL
POWER
REM STEP SCAN TALK LSTN SRQ SHIFT TIMER HOLD TRIG
CH1 FAST
CH2 CH3 CH4 MED SLOW REL
CH5 CH6 FILT AUTO
CH7 ERR
CH8 CH9 CH10 MATH REAR
4W BUFFER STAT
SENSE 4 WIRE
INPUT
HI
350V PEAK
!
1000V PEAK
MATH DCV
THD ACV
DELAY HOLD EX TRIG TRIG
SAVE SETUP SOURCE MEAS
TH D
dBm
dB
DCI ACI
LIMITS ON/OFF STORE RECALL
CONFIG HALT STEP SCAN
CONT 2 4
TEST CAL FILTER REL
GPIB RS232 DIGITS RATE
2015 THD MULTIMETER
PERIOD TCOUPL FREQ TEMP
RANGE
EXIT ENTER
AUTO RANGE
LO INPUTS
500V PEAK
F
R
FRONT/REAR
3A 250V AMPS
Input LO
Output HI
Current Calibrator
Amps
O utput LO
Note: Be sure calibrator is set for normal current output.
2. Calibrate each current step summarized in Table 2-5. For each step: · Set the calibrator to the indicated DC current, and make sure the unit is in operate. · Make sure the Model 2015 display indicates the correct calibration current. · Press ENTER to complete each step. · Allow the Model 2015 to finish each step.
NOTE If you are performing DC-only calibration, proceed to Setting calibration dates.
Table 2-5 DC current calibration summary
Calibration step
10mA 100mA 1A
Calibrator current
10.00000mA 100.0000mA 1.000000A
Allowable range
9mA to 11mA 90mA to 110mA 0.9A to 1.1A
Calibration
2-13
AC voltage calibration
Follow these steps for AC voltage calibration:
1. Connect the calibrator to the Model 2015 INPUT HI and LO terminals as shown in Figure 2-4.
Figure 2-4 Connections for AC volts calibration
Model 2015
SHIFT
LOCAL
POWER
REM STEP SCAN TALK LSTN SRQ SHIFT TIMER HOLD TRIG
CH1 FAST
CH2 CH3 CH4 CH5 CH6 CH7 MED SLOW REL FILT AUTO ERR
CH8 CH9 CH10 MATH REAR
4W BUFFER STAT
SENSE 4 WIRE
INPUT
HI
350V PEAK
!
1000V PEAK
MATH DCV
THD ACV
DELAY HOLD EX TRIG TRIG
SAVE SETUP SOURCE MEAS
TH D
dBm
dB
DCI ACI
LIMITS ON/OFF STORE RECALL
CONFIG HALT STEP SCAN
CONT 2 4
TEST CAL FILTER REL
GPIB RS232 DIGITS RATE
2015 THD MULTIMETER
PERIOD TCOUPL
FREQ TEMP
RANGE
AUTO RANGE
EXIT ENTER
LO INPUTS
500V PEAK
F
R
FRONT/REAR
3A 250V AMPS
Input HI Output HI
Input LO
O utput LO
AC Voltage Calibrator
2. Perform the calibration steps summarized in Table 2-6. For each step: · Set the calibrator to the indicated value, and make sure the calibrator is in operate. · Press ENTER to complete each step. · Wait until the Model 2015 completes each step.
Table 2-6 AC voltage calibration summary
Calibration step
10mV AC at 1kHz 100mV AC at 1kHz 100mV AC at 50kHz 1V AC at 1kHz 1V AC at 50kHz 10V AC at 1kHz 10V AC at 50kHz 100V AC at 1kHz 100V AC at 50kHz 700V AC at 1kHz
Calibrator voltage, frequency
10.00000mV, 1kHz 100.0000mV, 1kHz 100.0000mV, 50kHz 1.000000V, 1kHz 1.000000V, 50kHz 10.00000V, 1kHz 10.00000V, 50kHz 100.0000V, 1kHz 100.0000V, 50kHz 700.000V, 1kHz
2-14 Calibration
AC current calibration
After the 700VAC at 1kHz point has been calibrated, the unit will prompt you for 100mA at 1kHz. Follow these steps for AC current calibration:
1. Connect the calibrator to the AMPS and INPUT LO terminals of the Model 2015 as shown in Figure 2-3.
2. Perform the calibration steps summarized in Table 2-7. For each step: · Set the calibrator to the indicated current and frequency, and make sure the unit is in operate. · Press ENTER to complete each calibration step. · Allow the unit to complete each step before continuing.
Table 2-7 AC current calibration summary
Calibration step
100mA at 1kHz 1A at 1kHz 2A at 1kHz
Calibrator current, frequency
100.0000mA, 1kHz 1.000000A, 1kHz 2.000000A, 1kHz
Distortion calibration
1. Following AC current calibration, the Model 2015 will prompt you for the first distortion calibration point (see Table 2-8): 1V AT 137 HZ
2. Connect the low-distortion function generator to the front panel INPUT jacks (see Figure 2-5).
3. Set the function generator to output a 1V RMS sine wave at a frequency of 137Hz. 4. Press the Model 2015 ENTER key to complete the 137Hz calibration step. The unit will
prompt you for the second distortion calibration point: 1V AT 844 HZ 5. Set the function generator to output a 1V RMS sine wave at a frequency of 844Hz. 6. Press ENTER to complete the 844Hz calibration step.
Calibration
2-15
Figure 2-5 Connections for distortion calibration
Model 2015
BN C-to-D ual Banana Plug
Adapter
SHIFT
LOCAL
POWER
REM STEP SCAN TALK LSTN SRQ SHIFT TIMER HOLD TRIG
CH1 FAST
CH2 CH3 CH4 MED SLOW REL
CH5 CH6 FILT AUTO
CH7 ERR
CH8 CH9 CH10 MATH REAR
4W BUFFER STAT
SENSE 4 WIRE
INPUT
HI
350V PEAK
!
1000V PEAK
MATH DCV
THD ACV
DELAY HOLD EX TRIG TRIG
SAVE SETUP SOURCE MEAS
TH D
dBm
dB
DCI ACI
LIMITS ON/OFF STORE RECALL
CONFIG HALT STEP SCAN
CONT 2 4
TEST CAL FILTER REL
GPIB RS232 DIGITS RATE
2015 THD MULTIMETER
PERIOD TCOUPL FREQ TEMP
RANGE
AUTO RANGE
EXIT ENTER
LO INPUTS
500V PEAK
F
R
FRONT/REAR
3A 250V AMPS
Low Distortion Function Generator O utput
Coaxial Cable
Table 2-8 Distortion and function generator calibration summary
Calibration step
Distortion, 1V at 137Hz Distortion, 1V at 844Hz Function generator
Calibration signal or connections
1V RMS, 137Hz sine wave 1V RMS, 844Hz sine wave SOURCE OUTPUT to INPUT
Function generator calibration
1. Following distortion calibration, the Model 2015 will prompt you to connect the SOURCE OUTPUT jack to the INPUT jacks: INPUT FGEN
2. Connect the rear panel SOURCE OUTPUT jack to the front panel INPUT jacks (See Figure 2-6.)
3. Press the ENTER key to complete function generator calibration.
Figure 2-6 Connections for function generator calibration
Model 2015
SHIFT
LOCAL
POWER
REM TALK LSTN SRQ SHIFT TIMER
STEP SCAN HOLD TRIG
CH1 FAST
CH2 CH3 CH4 CH5 CH6 CH7 MED SLOW REL FILT AUTO ERR
CH8 CH9 CH10 MATH REAR
4W BUFFER STAT
SENSE 4 WIRE
INPUT
HI
350V PEAK
!
1000V PEAK
MATH DCV
THD ACV
DELAY HOLD EX TRIG TRIG
SAVE SETUP SOURCE MEAS
TH D
dBm
dB
DCI ACI
LIMITS ON/OFF STORE RECALL
CONFIG HALT STEP SCAN
CONT 2 4
TEST CAL FILTER REL
GPIB RS232 DIGITS RATE
2015 THD MULTIMETER
PERIOD TCOUPL
FREQ TEMP
RANGE
AUTO RANGE
EXIT ENTER
LO INPUTS
500V PEAK
F
R
FRONT/REAR
3A 250V AMPS
Connect INPUT jacks to rear panel SOURCE OUTPUT
2-16 Calibration
Setting calibration dates and saving calibration
At the end of the calibration procedure, the instrument will display the CALIBRATION COMPLETE message. Press ENTER to continue, and the Model 2015 will prompt you to enter the calibration date and the calibration due date. Set these dates as follows:
1. At the CAL DATE: mm/dd/yy prompt, use the left and right arrow keys, and the range keys to set the calibration date, then press ENTER.
2. The unit will then prompt you to enter the next calibration due date with this prompt: CAL NDUE: mm/dd/yy. Use the left and right arrow keys, and the range keys to set the calibration due date, then press ENTER.
3. The unit will prompt you to save new calibration constants with this message: SAVE CAL? YES. To save the new constants, press ENTER. If you do not want to save the new constants, press the down range key to toggle to NO, then press ENTER.
NOTE
Calibration constants calculated during the current calibration procedure will not be saved unless you choose the YES option. Previous calibration constants will be retained if you select NO.
Remote calibration
Follow the steps in this section to perform comprehensive procedures via remote. See Appendix B for a detailed list and description of remote calibration commands.
When sending calibration commands, be sure that the Model 2015 completes each step before sending the next command. You can do so either by observing the front panel CALIBRATING message, or by detecting the completion of each step over the bus. (See Detecting calibration step completion in Appendix B.)
The procedures for calibrating the Model 2015 via remote include:
· Preparing the Model 2015 for calibration · Front panel short and open calibration · DC volts calibration · Resistance calibration · DC current calibration · AC volts calibration · AC current calibration · Distortion calibration · Function generator calibration · Programming calibration dates · Saving calibration constants · Locking out calibration
NOTE
As with front panel calibration, you can choose to perform comprehensive, DC-only, AC-only, distortion, or function generator calibration. Be sure to include a space character between each command and parameter.
Calibration
2-17
Preparing the Model 2015 for calibration
1. Connect the Model 2015 to the IEEE-488 bus of the computer using a shielded IEEE-488 cable, such as the Keithley Model 7007, or connect the unit to a computer through the RS-232 port using a straight-through 9-pin to 9-pin cable (use a 9-25-pin adapter if necessary).
2. Turn on the Model 2015, and allow it to warm up for an hour before performing calibration.
3. Select the DCV function, and choose SLOW as the rate (integration time = 10PLC). 4. Make sure the primary address of the Model 2015 is the same as the address specified in
the program that you will be using to send commands. (Use the GPIB key.) 5. Unlock the calibration function by sending this command:
:CAL:PROT:CODE ‘KI002015’ (The above command shows the default code, KI002015. Substitute the correct code if changed.) 6. Send the following command to initiate calibration: :CAL:PROT:INIT
Short and open calibration
1. Connect the Model 8610 low-thermal short to the instrument INPUT and SENSE terminals as shown in Figure 2-1. Make sure the INPUTS button is not pressed in so that the front inputs are active. Wait at least three minutes before proceeding to allow for thermal equilibrium.
NOTE
Be sure to connect the low-thermal short properly to the HI, LO, and SENSE terminals. Keep drafts away from low-thermal connections to avoid thermal drift, which could affect calibration accuracy.
2. Send the following command: :CAL:PROT:DC:STEP1
3. After the Model 2015 completes this step, remove the low-thermal short, and send this command: :CAL:PROT:DC:STEP2
2-18 Calibration
DC voltscalibration
After front panel short and open steps, do the following:
1. Connect the calibrator to the Model 2015 as shown in Figure 2-2. Allow three minutes for thermal equilibrium.
NOTE
Although 4-wire connections are shown, the sense leads are connected and disconnected at various points in this procedure by turning calibrator external sense on or off as appropriate. If your calibrator does not have provisions for turning external sense on and off, disconnect the sense leads when external sensing is to be turned off, and connect the sense leads when external sensing is to be turned on.
2. Perform the calibration steps summarized in Table 2-9. For each step:
· Set the calibrator to the indicated voltage, and make sure the unit is in operate. (Use the recommended voltage if possible.)
· Send the indicated programming command. (Change the voltage parameter if you are using a different calibration voltage.)
· Wait until the Model 2015 completes each step before continuing.
Table 2-9 DC voltage calibration programming steps
Calibration Calibrator
step
voltage
Calibration command*
Parameter range
+10V -10V 100V
+10.00000V -10.00000V 100.0000V
:CAL:PROT:DC:STEP3 10 :CAL:PROT:DC:STEP4 10 :CAL:PROT:DC:STEP5 100
9 to 11 -9 to -11 90 to 110
* Use recommended value where possible. Change parameter accordingly if using a different calibrator voltage.
Calibration
2-19
Resistance calibration
Follow these steps for resistance calibration: 1. Set the calibrator to the resistance mode, and turn on external sensing. NOTE Use external sense (4-wire ) when calibrating all resistance ranges. Be sure that the
calibrator external sense mode is turned on.
2. Perform the calibration steps summarized in Table 2-10. For each step: · Set the calibrator to the indicated resistance, and make sure the unit is in operate. (Use the recommended resistance or the closest available value.) · Send the indicated programming command. (Change the command parameter if you are using a different calibration resistance than that shown.) · Wait until the Model 2015 completes each step before continuing.
Table 2-10 Resistance calibration programming steps
Calibration Calibrator
step
resistance Calibration command*
1k 10k 100k 1M
1k 10k 100k 1M
:CAL:PROT:DC:STEP6 1E3 :CAL:PROT:DC:STEP7 10E3 :CAL:PROT:DC:STEP8 100E3 :CAL:PROT:DC:STEP9 1E6
* Use exact calibrator resistance value for parameter.
Parameter range
900 to 1.1E3 9E3 to 11E3 90E3 to 110E3 900E3 to 1.1E6
2-20 Calibration
DC current calibration
After the 1M resistance point has been calibrated, follow these steps for DC current calibration:
1. Connect the calibrator to the AMPS and INPUT LO terminals of the Model 2015 as shown in Figure 2-3.
2. Perform the calibration steps listed in Table 2-11. For each step: · Set the calibrator to the indicated current, and make sure the unit is in operate. (Use the recommended current if possible.) · Send the indicated programming command. (Change the current parameter if you are using a different calibration current.) · Wait until the Model 2015 completes each step before continuing.
NOTE If you are performing DC-only calibration, proceed to Programming calibration dates.
Table 2-11 DC current calibration programming steps
Calibration Calibrator
step
current
Calibration command*
Parameter range
10mA 100mA 1A
10.00000mA 100.00000mA 1.000000A
:CAL:PROT:DC:STEP10 10E-3 :CAL:PROT:DC:STEP11 100E-3 :CAL:PROT:DC:STEP12 1
9E-3 to 11E-3 90E-3 to 110E-3 0.9 to 1.1
* Change parameter if using different current.
Calibration
2-21
AC voltage calibration
Follow these steps for AC voltage calibration:
1. Connect the calibrator to the Model 2015 INPUT HI and LO terminals as shown in Figure 2-4.
2. Perform the calibration steps summarized in Table 2-12. For each step: · Set the calibrator to the indicated voltage and frequency, and make sure the unit is in operate. (You must use the stated voltage and frequency.) · Send the indicated programming command. · Wait until the Model 2015 completes each step before continuing.
Table 2-12 AC voltage calibration programming steps
Calibration step
Calibrator voltage, frequency
Calibration command
10mV AC at 1kHz 100mV AC at 1kHz 100mV AC at 50kHz 1VAC at 1kHz 1VAC at 50kHz 10VAC at 1kHz 10VAC at 50kHz 100VAC at 1kHz 100VAC at 50kHz 700VAC at 1kHz
10.00000mV, 1kHz 100.0000mV, 1kHZ 100.0000mV, 50kHz 1.000000V, 1kHz 1.000000V, 50kHz 10.00000V, 1kHz 10.00000V, 50kHz 100.0000V, 1kHz 100.0000V, 50kHz 700.000V, 1kHz
:CAL:PROT:AC:STEP1 :CAL:PROT:AC:STEP2 :CAL:PROT:AC:STEP3 :CAL:PROT:AC:STEP4 :CAL:PROT:AC:STEP5 :CAL:PROT:AC:STEP6 :CAL:PROT:AC:STEP7 :CAL:PROT:AC:STEP8 :CAL:PROT:AC:STEP9 :CAL:PROT:AC:STEP10
2-22 Calibration
AC current calibration
Follow these steps for AC current calibration:
1. Connect the calibrator to the AMPS and INPUT LO terminals of the Model 2015 as shown in Figure 2-3.
2. Perform the calibration steps summarized in Table 2-13. For each step: · Set the calibrator to the indicated current and frequency, and make sure the unit is in operate. (You must use the stated current and frequency.) · Send the indicated programming command. · Wait until the Model 2015 completes each step before continuing.
Table 2-13 AC current calibration programming steps
Calibration step
100mA at 1kHz 1A at 1kHz 2A at 1kHz
Calibrator current, frequency Calibration command
100.0000mA, 1kHz 1.000000A, 1kHz 2.000000A, 1kHz
:CAL:PROT:AC:STEP11 :CAL:PROT:AC:STEP12 :CAL:PROT:AC:STEP13
Distortion calibration
1. Connect the low-distortion function generator to the front panel INPUT jacks (see Figure 2-5).
2. Set the function generator to output a 1V RMS sine wave at a frequency of 137Hz. 3. Send the following command to perform the 137Hz calibration step (see also Table
2-14): :CAL:PROT:DIST:STEP1 4. Set the function generator to output a 1V RMS sine wave at a frequency of 844Hz. 5. Send the following command to perform the 844Hz calibration step: :CAL:PROT:DIST:STEP2
Table 2-14 Distortion and function generator calibration steps
Calibration step
Calibration signal or connections Calibration command
Distortion, 1V at 137Hz 1V RMS, 137Hz sine wave
Distortion, 1V at 844Hz 1V RMS, 844Hz sine wave
Function generator
SOURCE OUTPUT to INPUT
:CAL:PROT:DIST:STEP1 :CAL:PROT:DIST:STEP2 :CAL:PROT:FGEN:STEP1
Calibration
2-23
Function generator calibration
1. Connect the rear panel SOURCE OUTPUT jack to the front panel INPUT jacks (see Figure 2-6.)
2. Send the following command to complete function generator calibration: :CAL:PROT:FGEN:STEP1
Programming calibration dates
Program the present calibration date and calibration due date by sending the following commands:
:CAL:PROT:DATE <year>, <month>, <day> :CAL:PROT:NDUE <year>, <month>, <day> For example, the following commands assume calibration dates of 12/15/97 and 3/14/98 respectively: :CAL:PROT:DATE 1997, 12, 15 :CAL:PROT:NDUE 1998, 3, 14
Saving calibration constants
After completing the calibration procedure, send the following command to save the new calibration constants:
:CAL:PROT:SAVE NOTE Calibration constants will not be saved unless the :SAVE command is sent.
Locking out calibration
After saving calibration, send the following command to lock out calibration: :CAL:PROT:LOCK
2-24 Calibration
Manufacturing calibration
The manufacturing procedure is normally performed only at the factory, but the necessary steps are included here in case the unit is repaired, and the unit requires these calibration procedures. NOTE If the unit has been repaired, the entire comprehensive calibration procedure should
also be performed in addition to the manufacturing calibration procedure.
Recommended test equipment
Table 2-15 summarizes the test equipment required for the manufacturing calibration steps. In addition, you will need the calibrator and signal generator (see Table 2-1) to complete the comprehensive calibration steps.
Table 2-15 Recommended equipment for manufacturing calibration
Keithley 3930A or 3940 Frequency Synthesizer: 1V RMS, 3Hz, ±5ppm 1V RMS, 1kHz, ±5ppm
Keithley Model 2001 or 2002 Digital Multimeter: 1V, 3Hz AC, ±0.13%
Keithley Model 8610 Low-thermal short
Unlocking manufacturing calibration
To unlock manufacturing calibration, press and hold in the SOURCE key while turning on the power.
Measuring synthesizer signal amplitude
The 3Hz synthesizer signal amplitude must be accurately measured using the digital multimeter listed in Table 2-15. Proceed as follows:
1. Connect the synthesizer output to the digital multimeter INPUT jacks. (See Figure 2-7 for typical connections.)
2. Turn on the synthesizer and multimeter, and allow a one-hour warm-up period before measuring.
3. Set the synthesizer to output a 1V RMS sine wave at 3Hz; measure and record the signal amplitude.
Calibration
2-25
Front panel manufacturing calibration
1. Connect the low-thermal short to the rear panel input jacks, and select the rear inputs with the INPUTS switch. Allow three minutes for thermal equilibrium.
2. Press in and hold the SOURCE key while turning on the power. 3. Press SHIFT then CAL, select RUN, then enter the appropriate calibration code (default:
002015). 4. Select ALL at the CAL:RUN prompt. 5. Press ENTER. 6. Perform the entire front panel comprehensive calibration procedure discussed earlier in
this section. (See Comprehensive calibration.) 7. Connect the synthesizer to the Model 2015 front panel INPUT jacks as shown in Figure
2-7. Select the front input jacks with the INPUTS switch.
Figure 2-7 Synthesizer connections for manufacturing calibration
Model 2015
BN C-to-D ual Banana Plug
Adapter
SHIFT
LOCAL
POWER
REM TALK LSTN SRQ SHIFT TIMER
STEP SCAN HOLD TRIG
CH1 FAST
CH2 CH3 CH4 CH5 CH6 CH7 MED SLOW REL FILT AUTO ERR
CH8 CH9 CH10 MATH REAR
4W BUFFER STAT
SENSE 4 WIRE
INPUT
HI
350V PEAK
!
1000V PEAK
MATH DCV
THD ACV
DELAY HOLD EX TRIG TRIG
SAVE SETUP SOURCE MEAS
TH D
dBm
dB
DCI ACI
LIMITS ON/OFF STORE RECALL
CONFIG HALT STEP SCAN
CONT 2 4
TEST CAL FILTER REL
GPIB RS232 DIGITS RATE
2015 THD MULTIMETER
PERIOD TCOUPL
FREQ TEMP
RANGE
AUTO RANGE
EXIT ENTER
LO INPUTS
500V PEAK
F
R
FRONT/REAR
3A 250V AMPS
Model 3930A or 3940 Synthesizer
M ai n Function O utput
50 BNC Coaxial Cable
Note: Synthesizer output voltage must be accurately measured. (See text)
8. After the last AC current calibration step, the instrument will prompt you to enter 3Hz at 1V RMS and 1kHz with the following prompts: · Low-frequency cal: Set the synthesizer to output a 1V RMS, 3Hz sine wave. Use the left and right arrow keys, and the range keys to adjust the display to agree with the synthesizer amplitude you measured previously, then press ENTER. · Frequency cal: Set the synthesizer to output a 1V RMS, 1kHz sine wave. Enter 1.000000kHz at the prompt, then press ENTER.
9. Set the calibration dates, then save calibration to complete the process.
2-26 Calibration
Remote manufacturing calibration
1. Connect the low-thermal short to the rear panel input jacks, and select the rear inputs with the INPUTS switch. Allow three minutes for thermal equilibrium.
2. Press in and hold the SOURCE key while turning on the power. 3. Enable calibration by sending the :CODE command. For example, the default command
is: :CAL:PROT:CODE ‘KI002015′
4. Initiate calibration by sending the following command: :CAL:PROT:INIT
5. Calibrate step 0 with the following command: :CAL:PROT:AC:STEP0
6. Perform the entire remote comprehensive calibration procedure discussed earlier in this section. (See Comprehensive calibration.)
7. Connect the synthesizer to the Model 2015 INPUT jacks as shown in Figure 2-7. Select the front input jacks with the INPUTS switch.
8. Set the synthesizer to output a 1V RMS, 3Hz sine wave, then send the following command: :CAL:PROT:AC:STEP14 <Cal_voltage> Here <Cal_voltage> is the actual 3Hz synthesizer signal amplitude you measured previously.
9. Set the synthesizer to output a 1V RMS, 1kHz sine wave, then send the following command: :CAL:PROT:AC:STEP15 1E3
10. Send the following commands to set calibration dates, save calibration, and lock out calibration: :CAL:PROT:DATE <year>, <month>, <day> :CAL:PROT:NDUE <year>, <month>, <day> :CAL:PROT:SAVE :CAL:PROT:LOCK
3
Routine Maintenance
3-2
Routine Maintenance
Introduction
The information in this section deals with routine type maintenance that can be performed by the operator and includes procedures for replacing both the line fuse and the amps fuse.
Setting the line voltage and replacing the line fuse
WARNING Disconnect the line cord at the rear panel, and remove all test leads connected to the instrument (front and rear) before replacing the line fuse.
The power line fuse is located in the power module next to the AC power receptacle (see Figure 3-1). If the line voltage must be changed, or if the line fuse requires replacement, perform the following steps:
1. Place the tip of a flat-blade screwdriver into the power module by the fuse holder assembly (see Figure 3-1). Gently push in and to the left. Release pressure on the assembly, and its internal spring will push it out of the power module.
2. Remove the fuse, and replace it with the type listed in Table 3-1.
CAUTION
For continued protection against fire or instrument damage, replace the fuse only with the type and rating listed. If the instrument repeatedly blows fuses, locate and correct the cause of the trouble before replacing the fuse.
3. If configuring the instrument for a different line voltage, remove the line voltage selector from the assembly, and rotate it to the proper position. When the selector is installed into the fuse holder assembly, the correct line voltage appears inverted in the window.
4. Install the fuse holder assembly into the power module by pushing it in until it locks in place.
Figure 3-1 Power module
Model 2015
WARNING:NO INTERNAL OPERATOR SERVICABLE PARTS,SERVICE BY QUALIFIED PERSONNEL ONLY.
HI
MADE IN
U.S.A.
1000V
350V PEAK
!
PEAK
TRIGGER LINK
500V
PEAK
!
LO
SENSE
INPUT
4W !
SOURCE OUTPUT
42V PEAK
INV/PULSE SOURCE
OUTPUT
135 24 6
VMC EXT TRIG
!
FUSE
LINE LINE RATING
500 mAT 100 VAC
50, 60Hz
(SB) 120 VAC 40VA MAX
250 mAT 220 VAC (SB) 240 VAC
RS232
IEEE-488 (CHANGE IEEE ADDRESS
FROM FRONT PANEL)
120
CAUTION:FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,REPLACE FUSE WITH SAME TYPE AND RATING.
Routine Maintenance
3-3
Fuse Spring
Table 3-1 Power line fuse
Line Voltage
100/120V 200/240V
Line Voltage Selector
120
Window Fuse Holder Assembly
Rating
Keithley Part No.
1/2A, 250V, 5 × 20 mm, slow-blow FU-71 1/4A, 250V, 5 × 20 mm, slow-blow FU-96-4
Replacing the AMPSfuse
The AMPS fuse protects the current input from an over-current condition. Follow the steps below to replace the AMPS fuse.
WARNING Make sure the instrument is disconnected from the power line and other equipment before replacing the AMPS fuse.
1. Turn off the power, and disconnect the power line and test leads. 2. From the front panel, gently push in the AMPS jack with your thumb, and rotate the fuse
carrier one-quarter turn counterclockwise. Release pressure on the jack, and its internal spring will push the fuse carrier out of the socket. 3. Remove the fuse, and replace it with the same type: 3A, 250V, fast blow, Keithley part number FU-99-1.
3-4
Routine Maintenance
CAUTION
Do not use a fuse with a higher current rating than specified, or instrument damage may occur. If the instrument repeatedly blows fuses, locate and correct the cause of the trouble before replacing the fuse.
4. Install the new fuse by reversing the above procedure.
4
Troubleshooting
4-2
Troubleshooting
Introduction
This section of the manual will assist you in troubleshooting and repairing the Model 2015. Included are self-tests, test procedures, troubleshooting tables, and circuit descriptions. It is left to the discretion of the repair technician to select the appropriate tests and documentation needed to troubleshoot the instrument.
WARNING
The information in this section is intended only for qualified service personnel. Do not perform these procedures unless you are qualified to do so. Some of these procedures may expose you to hazardous voltages that could cause personal injury or death. Use caution when working with hazardous voltages.
Troubleshooting
4-3
Repair considerations
Before making any repairs to the Model 2015, be sure to read the following considerations.
CAUTION
The PC-boards are built using surface mount techniques and require specialized equipment and skills for repair. If you are not equipped and/or qualified, it is strongly recommended that you send the unit back to the factory for repairs or limit repairs to the PC-board replacement level. Without proper equipment and training, you could damage a PC-board beyond repair.
· Repairs will require various degrees of disassembly. However, it is recommended that the Front Panel Tests be performed prior to any disassembly. The disassembly instructions for the Model 2015 are contained in Section 5 of this manual.
· Do not make repairs to surface mount PC-boards unless equipped and qualified to do so (see previous CAUTION).
· When working inside the unit and replacing parts, be sure to adhere to the handling precautions and cleaning procedures explained in Section 5.
· Many CMOS devices are installed in the Model 2015. These static-sensitive devices require special handling as explained in Section 5.
· Whenever a circuit board is removed or a component is replaced, the Model 2015 must be recalibrated. See Section 2 for details on calibrating the unit.
4-4
Troubleshooting
Power-on self-test
During the power-on sequence, the Model 2015 will perform a checksum test on its EPROM (U156 and U157) and test its RAM (U151 and U152). If one of these tests fails, the instrument will lock up.
Troubleshooting
4-5
Front panel tests
There are two front panel tests: one to test the functionality of the front panel keys and one to test the display. In the event of a test failure, refer to Display board checks for details on troubleshooting the display board.
KEY test
The KEY test allows you to check the functionality of each front panel key. Perform the following steps to run the KEY test:
1. Press SHIFT and then TEST to access the self-test options. 2. Use the up or down RANGE key to display “TEST: KEY”. 3. Press ENTER to start the test. When a key is pressed, the label name for that key is dis-
played to indicate that it is functioning properly. When the key is released, the message “NO KEY PRESS” is displayed. 4. Pressing EXIT tests the EXIT key. However, the second consecutive press of EXIT aborts the test and returns the instrument to normal operation.
DISP test
The display test allows you to verify that each segment and annunciator in the vacuum fluorescent display is working properly. Perform the following steps to run the display test:
1. Press SHIFT and then TEST to access the self-test options. 2. Use the up or down RANGE key to display “TEST: DISP”. 3. Press ENTER to start the test. There are four parts to the display test. Each time ENTER
is pressed, the next part of the test sequence is selected. The four parts of the test sequence are as follows: A. All annunciators are displayed. B. The segments of each digit are sequentially displayed. C. The 12 digits (and annunciators) are sequentially displayed. D. The annunciators located at either end of the display are sequentially displayed. 4. When finished, abort the display test by pressing EXIT. The instrument returns to normal operation.
4-6
Troubleshooting
Principles of operation
The following information is provided to support the troubleshooting tests and procedures covered in this section of the manual. Refer to the following block diagrams:
Figure 4-1 — Power supply block diagram Figure 4-2 — Digital circuitry block diagram Figure 4-3 — Analog circuitry block diagram Figure 4-4 — Distortion digital circuitry block diagram Figure 4-5 — Distortion analog circuitry block diagram Figure 4-6 — Sine generator circuitry block diagram
Power supply
The following information provides some basic circuit theory that can be used as an aid to troubleshoot the power supply. A block diagram of the power supply is shown in Figure 4-1.
Figure 4-1 Power supply block diagram
Fuse
Pow er Sw i tch
Line Voltage Sw i tch
Pow er Transformer
Pow er Transformer
CR104 C128, C156
U144
CR116, CR117 C104, C108 U101
CR102 C131, C148 U119, U125
CR103 C146 U124
CR301 C350 U331
CR330 CR331 C562 C565 C568 U348 U349 U350
+5VD
D Common +37V
D Common +15V A Common -15V +5V, +5VRL
A Common +5VD2
D Common
+15VF F Common -15VF +5VF
Troubleshooting
4-7
AC power is applied to the AC power module receptacle (J1009). Power is routed through the line fuse and line voltage selection switch of the power module to the power transformer. The power transformer has a total of four secondary windings for the various supplies.
AC voltage for the display filaments is taken from a power transformer secondary at F1 and F2, and then routed to the display board.
Each DC supply uses a rectifier and a capacitive filter, and many supplies use an IC regulator. Table 4-1 summarizes rectifier, filter, and regulator circuits for the various DC supplies.
Table 4-1 Power supply components
Supply
+5VD +37V +15V -15V +5V, +5VRL +5VD2 +15VF -15VF +5VF
Rectifier
CR104 CR116, CR117 CR102 CR102 CR103 CR301 CR330 CR330 CR331
Filter
C128, C156 C104, C106 C148 C131 C146 C350 C562 C565 C568
Regulator
U144 U101 U125 U119 U124 U331 U348 U349 U350
4-8
Troubleshooting
Display board
Display board components are shown in the digital circuitry block diagram in Figure 4-2.
Figure 4-2 Digital circuitry block diagram
N VRAM U136
RO M
RO M
U156, U157 U156, U157
Keypad
Analog Circuitry
(See Figure 4-3)
XAD TX XAD CLK XAD TS
XAD RX
O P T O
I S O
AT101 U150 U155
AD TX AD CLK AD TS
ADRXB
Scan Control
68306 µP
U135
Trigger
TRIG IN
U146, U164 TRIG OUT
Trigger Link
Display Board Controller U401
D i spl ay D S401
IN OUT
IN OUT
XTAL Y101
RS-232 U159
GPIB U158, U160,
U161
RS-232 Port
IEEE-488 Bus
TD TX TD CLK TD TS XTD RX
D i storti on Digital Circuit (See Figure 4-4)
Microcontroller
U401 is the display board microcontroller that controls the display and interprets key data. The microcontroller uses three internal peripheral I/O ports for the various control and read functions.
Display data is serially transmitted to the microcontroller from the digital section via the TXB line to the microcontroller RDI terminal. In a similar manner, key data is serially sent back to the digital section through the RXB line via TDO. The 4MHz clock for the microcontroller is generated by crystal Y401.
Troubleshooting
4-9
Display
DS401 is the display module, which can display up to 12 alpha-numeric characters and includes the various annunciators.
The display uses a common multiplexing scheme with each character refreshed in sequence. U402 and U403 are the drivers for the display characters and annunciators. Note that data for the drivers are serially transmitted from the microcontroller (MOSI and PC1).
Filament voltage for the display is derived from the power supply transformer (F1 and F2). The display drivers require +37VDC and +5VDC, which are supplied by U144 (+5VD) and U101 (+37V).
Key matrix
The front panel keys (S401-S430) are organized into a row-column matrix to minimize the number of microcontroller peripheral lines required to read the keyboard. A key is read by strobing the columns and reading all rows for each strobed column. Key-down data is interpreted by the display microcontroller and sent back to the main microprocessor using proprietary encoding schemes.
Digital circuitry
Refer to Figure 4-2 for the following discussion on digital circuitry.
Microprocessor
U135 is a 68306 microprocessor that oversees all operating aspects of the instrument. The MPU has a 16-bit data bus and provides an 18-bit address bus. It also has parallel and serial ports for controlling various circuits. For example, the RXDA, TXDA, RXDB and TXDB lines are used for the RS-232 interface.
The MPU clock frequency of 14.7456MHz is controlled by crystal Y101. MPU RESET is performed momentarily (through C241) on power-up by the +5VD power supply.
Memory circuits
ROMs U156 and U157 store the firmware code for instrument operation. U157 stores the D0D7 bits of each data word, and U156 stores the D8-D15 bits.
RAMs U151 and U152 provide temporary operating storage. U152 stores the D0-D7 bits of each data word, and U151 stores the D8-D15 bits.
Semi-permanent storage facilities include NVRAM U136. This IC stores such information as instrument setup and calibration constants. Data transmission from this device is done in a serial fashion.
4-10 Troubleshooting
RS-232 interface
Serial data transmission and reception is performed by the TXDB and RXDB lines of the MPU. U159 provides the necessary voltage level conversion for the RS-232 interface port.
IEEE-488 interface
U158, U160, and U161 make up the IEEE-488 interface. U158, a 9914A GPIA, takes care of routine bus overhead such as handshaking, while U160 and U161 provide the necessary buffering and drive capabilities.
Trigger circuits
Buffering for Trigger Link input and output is performed by U146. Trigger input and output is controlled by the IRQ4 and PB3 lines of the MPU. U164 provides additional logic for the trigger input to minimize MPU control overhead.
At the factory, trigger output is connected to line 1 of the Trigger Link connector (resistor R267 installed). Trigger input is connected to line 2 of the Trigger Link connector (resistor R270 installed).
Troubleshooting
4-11
Analog circuitry
Refer to Figure 4-3 for the following discussion on analog circuitry.
Figure 4-3 Analog circuitry block diagram
AM PS
Current Shunts K103, R158, R205
D CA ACA
AC Switching &
Gain K102, U102, U103, U105, U112, U118, U111, U110
IN PU T HI
ACV, FREQ
SSP* Q101, Q102
D CV OHMS
DCV & Ohms Sw i tchi ng
K101, Q104, Q105, Q108, Q113, U115
D CV D i vi der R117, Q109, Q114, Q136
Ohms I-Source U133, Q123, Q125, Q124, Q126, Q119, Q120, U123
SEN SE HI
SEN SE LO
D CV/100
X1 Buffer Q121, U126
* Solid State Protection
D i storti on Analog Circuitry
(See Figure 4-5)
X1 Buffer U 113
BU FCO M
A/D MUX &
Gain U163, U166 U129, U132
ADC U165
D i gi tal Circuitry (See Figure 4-2)
Scanner O utput
Scanner Inputs
Scanner Scanner Control O pti on
INPUT HI
INPUT HI protection is provided by the SSP (solid state protection) circuit. The SSP is primarily made up of Q101 and Q102. An overload condition opens Q101 and Q102, which disconnects the analog input signal from the rest of the analog circuit.
Note that for the 100VDC and 1000VDC ranges, Q101 and Q102 of the SSP are open. The DC voltage signal is routed through the DCV Divider (Q114 and Q136 on) to the DCV switching circuit.
4-12 Troubleshooting
AMPSinput
The ACA or DCA input signal is applied to the Current Shunt circuit, which is made up of K103, R158, and R205. For the 10mA DC range, 10.1 (R158 + R205) is shunted across the input. Relay K103 is energized (on) to select the shunts. For all other DCA ranges, and all ACA ranges, 0.1 (R158) is shunted across the input (K103 off).
The ACA signal is then sent to the AC Switching & Gain circuit, while the DCA signal is routed directly to the A/D MUX & Gain circuit.
Signal switching
Signal switching for DCV and OHMS is done by the DCV & Ohms Switching circuit. FETs Q113, Q105, Q104, and Q108 connect the DCV or ohms signal to the X1 buffer (U113).
Note that the reference current for OHMS is generated by the Ohms I-Source circuit. For 4-wire ohms measurements, SENSE LO is connected to the circuit by turning on Q121.
Signal switching and gain for ACV, FREQ and ACA is done by the AC Switching & Gain circuit, which is primarily made up of K102, U102, U103, U105, U112, U118, U111, and U110. Note that U111 is used for frequency adjustment. The states of these analog switches vary from unit to unit.
Multiplexer and A/D converter
All input signals, except FREQ, are routed to the A/D MUX & Gain circuit. The multiplexer (U163) switches the various signals for measurement. In addition to the input signal, the multiplexer also switches among reference and zero signals at various phases of the measurement cycle.
When the input signal is selected by the MUX, it is amplified by U132 and U166. Gain is controlled by switches in U129 and associated resistors.
The multiplexed signals of the measurement cycle are routed to the A/D Converter (U165) where it converts the analog signals to digital form. The digital signals are then routed through an opto-isolator to the MPU to calculate a reading.
Troubleshooting
4-13
Distortion digital circuitry
Refer to Figure 4-4 for the following discussion on the distortion digital circuitry.
Figure 4-4 Distortion digital circuitry block diagram
RO M U330
O SC
J T A G J3
D SP U329
D IGITAL (See Figure 4-2)
FPGA U327
EEPRO M U326
FD TX FD CLK FD TS
TD TX TD CLK TD TS TD VAL
U312, U313, U316, U317, U318, U319 OPTO ISO
OPTO ISO
XFD TX XFD CLK XFD TS
XTD TX XTD CLK XTD TS XTD VAL
D ISTO RTIO N AN ALO G CIRCU ITRY
(See Figure 4-5)
SIN EGEN CIRU ITRY
(See Figure 4-6)
4-14 Troubleshooting
DSP
U329 is a ADSP21061 digital signal processor that acquires ADC data, performs all distortion and noise calculations, and communicates the results to the microprocessor. The DSP has a 48-bit data bus and provides a 32-bit address bus. It has serial ports for communicating with serial peripherals such as the ADC and DAC converters. The DSP also has 1Mb of internal RAM for temporary data storage.
The DSP clock frequency of 33.0 MHz is controlled by oscillator Y303. DSP reset is performed by U333 through U327 and U326.
ROM U330 stores the firmware code for the DSP.
JTAG interface
J3 is the JTAG interface, and it is used for monitoring and debugging DSP code.
FPGA
U327 is an FPGA that provides all interface functions among the DSP, sine generator optoisolators, distortion analog circuitry, and the microprocessor. Upon power-up, the FPGA is configured by U326, an EEPROM.
Opto-isolators
U312, U313, U317, and U322 are drivers for the opto-isolators U316, U317, U318, U319, U320, U321, and U304. These isolators eliminate leakage currents and ground currents among the analog, digital, and sine wave generator circuits.
Troubleshooting
4-15
Distortion analog circuitry
Refer to Figure 4-5 for the following discussion on distortion analog circuitry.
Figure 4-5 Distortion analog circuitry block diagram
Analog Circuitry
(See Figure 4-3)
Amplifier Filter U309, U310
ADC Converter U 311
D i storti on D i gi tal Circuitry
(See Figure 4-4)
O SC Y301
ADC Clock Generator
U325
FPGA U314
EEPRO M U315
Amplifier filter
The buffered and scaled AC waveform from the analog circuitry (Figure 4-3) is fed to U309 and U310. U309 and U310 form an amplifier, antialiasing filter, and DC shifting circuit to condition the AC waveform for the distortion measurement ADC converter.
ADC converter
The distortion measurement circuitry uses a separate ADC converter from the rest of the DMM measurements (see U165 in Figure 4-3). This ADC is a high-speed, high-resolution, lowdistortion sigma delta type. The ADC digital output is sent to the DSP through opto-isolators shown in Figure 4-5.
ADC clock
Y301 is a fixed frequency clock that forms the input to U325, an adjustable frequency clock generator. The output of this generator clocks the ADC, setting the acquisition rate. The clock generator frequency is set by the microprocessor and is communicated through U314, the FPGA. The FPGA, U314, is configured by U315, an EEPROM, upon power-up.
4-16 Troubleshooting
Sine generator circuitry
Refer to Figure 4-6 for the following discussion on the sine generator circuitry.
Figure 4-6 Sine generator circuitry block diagram
Inv-Sine/pulse
-1 Comparator
Inv Sine/ Pulse Out
K301 50/600 Ohm
O SC
Sine Generator U301
Attenuator U303, U334 U335
Filter U307
+1
U305 U306 U307 U308
Source O utput
FPGA
EEPRO M
Distortion Digital Circuitry (see Figure 4-4)
Sine generator
Y302 is a fixed frequency clock that forms the input to U301, the adjustable frequency sine wave generator. The sine wave generator’ s frequency is set by the microprocessor through the FPGA, U334, and the opto-isolators U304, U320, and U321.
Attenuator
U303, U334, U335, and U302 form the adjustable attenuator that adjusts the sine wave output amplitude. The output amplitude is set by the microprocessor through the FPGA, U334, and the opto-isolators U304, U320, and U321.
Troubleshooting
4-17
Filter
U307, U336, and U337 form a low pass filter with a software-selectable cutoff frequency. This filter is used to reduce spurious noise in the sine wave output. The filter cutoff frequency is set by the microprocessor through the FPGA, U334, and opto-isolators U304, U320, and U321.
Outputs
The Model 2015 has two outputs. U305, U306, U307, and U308 form the main sine wave output stage.
The secondary output may be either an inverted sine wave of the same magnitude and frequency as the main sine wave output, or a 5V pulse output of the same frequency as the main sine wave. One IC is a comparator that squares up the main sine wave output. Another IC selects whether the sinewave or the comparator is fed to the output.
K301 selects between either 50 or 600 output impedance.
4-18 Troubleshooting
Troubleshooting
Troubleshooting information for the various circuits is summarized below. See Principles of operation for circuit theory.
Display board checks
If the front panel DISP test indicates that there is a problem on the display board, use Table 4-2.
Table 4-2 Display board checks
Step Item/component
Required condition
Remarks
1
Front panel DISP test. Verify that all segments operate. Use front panel display test.
2
P1005, PIN 5
+5V ±5%
Digital +5V supply.
3
P1005, PIN 9
+37V ±5%
Display +37V supply.
4
U401, PIN 1
Goes low briefly on power up, Microcontroller RESET.
then goes high.
5
U401, PIN43
4MHz square wave.
Controller 4MHz clock.
6
U401, PIN 32
Pulse train every 1msec.
Control from main processor.
7
U401, PIN 33
Brief pulse train when front
Key down data sent to main
panel key is pressed.
processor.
Troubleshooting
4-19
Power supply checks
Power supply problems can be checked out using Table 4-3.
Table 4-3 Power supply checks
Step Item/component
1
Line fuse
2
Line voltage
3
Line power
4
U144, pin 2
5
U101, pin 7
6
U125, pin 3
7
U119, pin 3
8
U124, pin 3
9
U331, pin 2
10
U348, pin 3
11
U349, pin 3
12
U350, pin 3
Required condition
Check continuity. 120V/240V as required. Plugged into live receptacle, power on. +5V ±5% +37V ±5% +15V ±5% -15V ±5% +5V ±5% +5V, ±3% +15V, ±5% -15V, ±5% +5V, ±5%
Remarks
Remove to check. Check power module position. Check for correct power-up sequence. +5VD, referenced to Common D. +37V, referenced to Common D. +15V, referenced to Common A. -15V, referenced to Common A. +5VRL, referenced to Common A. +5VD2, referenced to Common D. +15VA, referenced to Common F. -15VA, referenced to Common F. +5VA, referenced to Common F.
4-20 Troubleshooting
Digital circuitry checks
Digital circuit problems can be checked out using Table 4-4.
Table 4-4 Digital circuitry checks
Step Item/component
1
Power-on test
2
U152 pin 14
3
U152 pin 28
4
U135 pin 48
5
U135, lines A1-A23
6
U135, lines D1-D15
7
U135 pin 44
8
U159 pin 13
9
U159 pin 14
10
U158 pins 34-42
11
U158 pins 26-31
12
U158 pin 24
13
U158 pin 25
14
U135 pin 84
15
U135 pin 91
16
U135 pin 90
17
U135 pin 89
Required condition
RAM OK, ROM OK.
Digital common.
+5V Low on power-up, then goes high. Check for stuck bits. Check for stuck bits. 14.7456MHz Pulse train during RS-232 I/O. Pulse train during RS-232 I/O. Pulse train during IEEE-488 I/O. Pulses during IEEE-488 I/O. Low with remote enabled. Low during interface clear. Pulse train. Pulse train. Pulse train. Pulse train.
Remarks
Verify that RAM and ROM are functional. All signals referenced to digital common. Digital logic supply. MPU RESET line.
MPU address bus. MPU data bus. MPU clock. RS-232 RX line. RS-232 TX line. IEEE-488 data bus.
IEEE-488 command lines. IEEE-488 REN line. IEEE-488 IFC line. ADRXB ADTX ADCLK ADTS
Troubleshooting
4-21
Analog signal switching states
Tables 4-5 through 4-11 provide switching states of the various relays, FETs, and analog switches for the basic measurement functions and ranges. These tables can be used to assist in tracing an analog signal from the input to the A/D multiplexer.
Table 4-5 DCV signal switching
Range Q101 Q102
100mV ON ON
1V
ON ON
10V
ON ON
100V OFF OFF
1000V OFF OFF
* K101 set states:
Q114 Q136 Q109
OFF OFF OFF OFF OFF OFF OFF OFF OFF ON ON OFF ON ON OFF
Pin 8 switched to Pin 7 Pin 3 switched to Pin 4
K101* Q113
SET OFF SET OFF SET OFF SET OFF SET OFF
Q105
OFF OFF OFF OFF OFF
Q104
ON ON ON OFF OFF
Q108
OFF OFF OFF ON ON
Q121
ON ON ON ON ON
Table 4-6 ACV and FREQ signal switching
U103 U103 U105 U105 U103 U103 U105 U111 Range Q101 Q102 K101* K102* pin 8 pin 9 pin 9 pin 8 pin 16 pin 1 pin 1 pin 16
100mV ON ON RESET RESET ON ON OFF OFF OFF ON ON OFF 1V ON ON RESET RESET ON ON OFF OFF ON OFF OFF OFF 10V ON ON RESET SET OFF OFF ON OFF OFF ON ON OFF 100V ON ON RESET SET OFF OFF ON OFF ON OFF OFF OFF 750V ON ON RESET SET OFF OFF ON ON OFF OFF OFF OFF
* K101 and K102 reset states: K101 and K102 set states:
Pin 8 switched to Pin 9 Pin 3 switched to Pin 2 Pin 8 switched to Pin 7 Pin 3 switched to Pin 4
4-22 Troubleshooting
Table 4-7 2 signal switching
Range Q101 Q102 Q114 Q136 Q109 K101* K102* Q113 Q105 Q104 Q108 Q121
100 ON ON OFF OFF OFF SET RESET OFF ON OFF OFF ON 1k ON ON OFF OFF OFF SET RESET OFF ON OFF OFF ON 10k ON ON OFF OFF OFF SET RESET OFF ON OFF OFF ON 100k ON ON OFF OFF OFF SET RESET OFF ON OFF OFF ON 1M ON ON OFF OFF OFF SET RESET OFF ON OFF OFF ON 10M ON ON OFF OFF ON SET RESET OFF ON OFF OFF ON 100M ON ON OFF OFF ON SET RESET OFF ON OFF OFF ON
* K101 set states: K102 reset states:
Pin 8 switched to Pin 7 Pin 3 switched to Pin 4 Pin 8 switched to Pin 9 Pin 3 switched to Pin 2
Table 4-8 4 signal switching
Range Q101
100 ON
1k
ON
10k ON
100k ON
1M ON
10M ON
100M ON
*K101 set states:
Q102
ON ON ON ON ON ON ON
Q114 Q136 Q109
OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF ON OFF OFF ON
Pin 8 switched to Pin 7 Pin 3 switched to Pin 4
K101* Q113
SET ON SET ON SET ON SET ON SET ON SET OFF SET OFF
Q105
OFF OFF OFF OFF OFF ON ON
Q104
OFF OFF OFF OFF OFF OFF OFF
Q108
OFF OFF OFF OFF OFF OFF OFF
Q121
ON ON ON ON ON ON ON
Table 4-9 2/4 reference switching
Range U133/0.7 U133/7V Q123 Q125 Q124 Q126 Q120
100 OFF
ON
ON ON OFF OFF ON
1k
OFF
ON
ON ON OFF OFF ON
10k OFF
ON
OFF OFF ON ON ON
100k ON
OFF
OFF OFF ON ON ON
1M ON
OFF
OFF OFF ON ON ON
10M OFF
ON
OFF OFF ON ON OFF
100M OFF
ON
OFF OFF ON ON OFF
Troubleshooting
4-23
Table 4-10 DCA signal switching
Range
10mA 100mA 1A 3A
K103
ON OFF OFF OFF
Table 4-11 ACA signal switching
Range
1A 3A
K103
OFF OFF
U105 U105 pin 16 pin 1
ON ON ON ON
U111 U105 pin 16 pin 8
OFF OFF ON OFF
U103 U103 pin 16 pin 1
OFF OFF OFF OFF
Tables 4-12 through 4-16 can be used to trace the analog signal through the A/D multiplexer (U163) to the final amplifier stage. These tables show the MUX lines (S3, S4, S6, S7) that are selected for measurement during the SIGNAL phase of the multiplexing cycle. Also included are switching states of analog switches (U129) that set up the gain for the final amplifier stage (U166).
Table 4-12 DCV signal multiplexing and gain
Range
100mV 1V 10V 100V 1000V
Signal (U163)
S4 S4 S4 S4 S4
U129 pin 1
OFF OFF ON OFF ON
U129 pin 8
OFF ON OFF ON OFF
U129 pin 9
ON OFF OFF OFF OFF
Gain (U166)
×100 ×10 ×1 ×10 ×1
Table 4-13 ACV and ACA signal multiplexing and gain
Signal Range (U163)
U129 U129 U129 Gain pin 1 pin 8 pin 9 (U166)
All
S3
ON OFF OFF ×1
4-24 Troubleshooting
Table 4-14 DCA signal multiplexing and gain
Range
10mA 100mA 1A 3A
Signal (U163)
S6 S6 S6 S6
U129 pin 1
OFF OFF OFF OFF
U129 pin 8
OFF OFF OFF ON
U129 pin 9
ON ON ON OFF
Gain (U166)
×100 ×100 ×100 ×10
Table 4-15 2 signal multiplexing and gain
Signal Range (U163)
U129 U129 U129 Gain pin 1 pin 8 pin 9 (U166)
100 S4
1k
S4
10k S4
100k S4
1M S4
10M S4
100M S4
OFF OFF ON ×100 OFF ON OFF ×10 OFF ON OFF ×10 OFF ON OFF ×10 ON OFF OFF ×1 ON OFF OFF ×1 ON OFF OFF ×1
Table 4-16 4 signal multiplexing and gain
Range
100 1k 10k 100k 1M 10M 100M
Signal (U163)
U129 pin 1
S4 then S7 OFF S4 then S7 OFF S4 then S7 OFF S4 then S7 OFF S4 then S7 ON S4 then S7 ON S4 then S7 ON
U129 pin 8
OFF ON ON ON OFF OFF OFF
U129 pin 9
ON OFF OFF OFF OFF OFF OFF
Gain (U166)
×100 ×10 ×10 ×10 ×1 ×1 ×1
Troubleshooting
4-25
Figure 4-3 provides a block diagram of the analog circuitry. Table 4-17 shows where the various switching devices are located in the block diagram.
Table 4-17 Switching device locations
Switching devices
Q101, Q102 Q114, Q136, Q109 K101, Q113, Q105, Q104, Q108 Q121 K102, U103, U105, U111 U133, Q120, Q123, Q124, Q125, Q126 K103 U129, U163
Analog circuit section (see Figure 4-3)
SSP (Solid State Protection) DCV Divider DCV and Ohms Switching Sense LO AC switching and Gain Ohms I-Source Current Shunts A/D Mux and Gain
5
Disassembly
5-2
D i sassembl y
Introduction
This section explains how to handle, clean, and disassemble the Model 2015 Multimeter. Disassembly drawings are located at the end of this section.
D i sassembl y
5-3
Handling and cleaning
To avoid contaminating PC board traces with body oil or other foreign matter, avoid touching the PC board traces while you are repairing the instrument. Motherboard areas covered by the shield have high-impedance devices or sensitive circuitry where contamination could cause degraded performance.
Handling PC boards
Observe the following precautions when handling PC boards:
· Wear cotton gloves. · Only handle PC boards by the edges and shields. · Do not touch any board traces or components not associated with repair. · Do not touch areas adjacent to electrical contacts. · Use dry nitrogen gas to clean dust off PC boards.
Solder repairs
Observe the following precautions when soldering a circuit board:
· Use an OA-based (organic activated) flux, and take care not to spread the flux to other areas of the circuit board.
· Remove the flux from the work area when you have finished the repair by using pure water with clean, foam-tipped swabs or a clean, soft brush.
· Once you have removed the flux, swab only the repair area with methanol, then blow dry the board with dry nitrogen gas.
· After cleaning, allow the board to dry in a 50°C, low-humidity environment for several hours.
5-4
D i sassembl y
Static sensitive devices
CMOS devices operate at very high impedance levels. Therefore, any static that builds up on you or your clothing may be sufficient to destroy these devices if they are not handled properly. Use the following precautions to avoid damaging them:
CAUTION Many CMOS devices are installed in the Model 2015. Handle all semiconductor devices as being static sensitive.
· Transport and handle ICs only in containers specially designed to prevent static buildup. Typically, you will receive these parts in anti-static containers made of plastic or foam. Keep these devices in their original containers until ready for installation.
· Remove the devices from their protective containers only at a properly grounded work station. Also, ground yourself with a suitable wrist strap.
· Handle the devices only by the body; do not touch the pins. · Ground any printed circuit board into which a semiconductor device is to be inserted to
the bench or table. · Use only anti-static type desoldering tools. · Use only grounded-tip solder irons. · Once the device is installed in the PC board, it is normally adequately protected, and you
can handle the boards normally.
D i sassembl y
5-5
Assembly drawings
Use the following assembly drawings to assist you as you disassemble and re-assemble the Model 2015. Also, refer to these drawings for information about the Keithley part numbers of most mechanical parts in the unit. The drawings are located at the end of this section of the manual.
· Front Panel Assembly — 2015-040 · Chassis/Transformer Power Module Assembly — 2015-050 · Front Panel/Chassis Assembly — 2015-051 · Chassis Assembly — 2015-052, 2015-053 · Final Inspection — 2015-080
5-6
D i sassembl y
Disassembly procedures
Case cover removal
Follow the steps below to remove the case cover to gain access to internal parts.
WARNING Before removing the case cover, disconnect the line cord and any test leads from the instrument.
1. Remove Handle — The handle serves as an adjustable tilt-bail. Adjust its position by gently pulling it away from the sides of the instrument case and swinging it up or down. To remove the handle, swing the handle below the bottom surface of the case and back until the orientation arrows on the handles line up with the orientation arrows on the mounting ears. With the arrows lined up, pull the ends of the handle away from the case.
2. Remove Mounting Ears — Remove the screw that secures each mounting ear. Pull down and out on each mounting ear.
NOTE
When re-installing the mounting ears, make sure to mount the right ear to the right side of the chassis, and the left ear to the left side of the chassis. Each ear is marked “RIGHT” or “LEFT” on its inside surface.
3. Remove Rear Bezel — To remove the rear bezel, loosen the two captive screws that secure the rear bezel to the chassis. Pull the bezel away from the case.
4. Removing Grounding Screws — Remove the two grounding screws that secure the case to the chassis. They are located on the bottom of the case at the back.
5. Remove Cover — To remove the case, grasp the front bezel of the instrument, and carefully slide the chassis forward. Slide the chassis out of the metal case.
NOTE To gain access to the components under the DMM board shield, remove the shield, which is secured to the DMM board by a single screw.
DMM board removal
Perform the following steps to remove the DMM (106) board. This procedure assumes that the case cover is already removed.
1. Remove the IEEE-488 and RS-232 fasteners. The IEEE-488 and the RS-232 connectors each have two nuts that secure the connectors to the rear panel. Remove these nuts.
2. Remove the front/rear switch rod. At the switch, place the edge of a flat-blade screw driver in the notch on the pushrod. Gently twist the screw driver while pulling the rod from the shaft.
D i sassembl y
5-7
3. Disconnect the front and rear input terminals. You must disconnect these input terminal connections for both the front and rear inputs: · INPUT HI and LO · SENSE HI and LO · AMPS Remove all the connections except the front AMPS connection by pulling the wires off the pin connectors. To remove the front panel AMPS input wire (white), first remove the AMPS fuse holder, then use needle-nose pliers to grasp the AMPS wire near fuse housing. Push the wire forward and down to snap the spring out of the fuse housing. Carefully pull the spring and contact tip out of the housing.
4. Unplug cables: · Unplug the display board ribbon cable from connector J1014. · Unplug the transformer cables from connectors J1016 and J1015. · Unplug the OPTION SLOT ribbon cable from connector J1017.
5. Remove the fastening screw that secures the DMM board to the chassis. One of these screws is located along the left side of the unit towards the rear, and it also secures U114. The other screw is located at the right front of the chassis near the front/rear switch, S101. During re-assembly, replace the board, and start the IEEE-488 and RS-232 connector nuts and the mounting screw. Tighten all the fasteners once they are all in place and the board is correctly aligned.
6. Remove the DMM board, which is held in place by edge guides on each side, by sliding it forward until the board edges clear the guides. Carefully pull the DMM board from the chassis.
DSP board removal
Perform the following steps to remove the DSP (136) board. This procedure assumes that the case cover and the DMM board have been removed.
1. Remove the nuts from the two BNC jack
Documents / Resources
 |
KEITHLEY 2015 THD Multimeter [pdf] User Manual 2015 THD Multimeter, 2015 THD, Multimeter |