Keithley 2015 Service Manual

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Model 2015

THD Multimeter

Service Manual

SHIFT

LOCAL

POWER

SCAN

STEP CH2 CH3 CH4 CH5 CH6 CH7 CH8 CH9 CH10 TALK LSTN SRQ SHIFT TIMER

MATH

DCV

EX TRIG

SAVE SETUP

SOURCE

CH1REM

HOLD TRIG FAST MED SLOW AUTO ERR

THD

ACV

HOLD

TRIG

MEAS

THD

dBm

DCI

LIMITS ON/OFFDELAY

STORE

RECALL

CONFIG HALT

STEP SCAN

ACI

REL FILT

CONT

Ω2 Ω4

TEST

GPIB

DIGITS RATE

Contains Servicing Information

CAL

RELFILTER

RS232

MATH REAR

BUFFER

STAT

2015 THD MULTIMETER

PERIOD TCOUPL

FREQ

TEMP

EXIT ENTER

RANGE

AUTO

RANGE

Ω 4 WIRE

350V PEAK

FRONT/REAR

SENSE

INPUTS

INPUT

1000V

PEAK

500V PEAK

3A 250V

AMPS

W ARRANTY

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.

T o e xercise this w arranty, write or call your local Keithle y representati v e, or contact K eithle y 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.

LIMIT A TION OF W ARRANTY

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

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 Le vel letter increases alphabetically as the manual under goes 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 Re vision is created, all Addenda associated with the previous Re vision of the manual are incorporated into the new Revision of the manual. Each ne w 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 v oltages, 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 e xists 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 an y 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.

T o clean an instrument, use a damp cloth or mild, water based cleaner . Clean the e xterior 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

T able of Contents

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

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

Routine Maintenance

Introduction ....................................................................................... 3-2

Setting the line voltage and replacing the line fuse ....................... 3-2

Replacing the AMPS fuse .............................................................. 3-3

T roubleshooting

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

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

Replaceable Parts

Introduction ........................................................................................ 6-2

Parts lists ............................................................................................ 6-2

Ordering information ......................................................................... 6-2

Factory service ................................................................................... 6-2

Component layouts ............................................................................ 6-2

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

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

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

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 Ω -10M Ω range) ........ 1-14

Connections for resistance veriﬁcation (100M Ω 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

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

Routine Maintenance

Power module .................................................................................... 3-3

T roubleshooting

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

Disassembly

Trigger link line connections ........................................................... 5-10

List of T ables

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

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

Ω

Ω 2/ Ω

Routine Maintenance

Power line fuse ............................................................................... 3-3

T roubleshooting

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

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

Disassembly

Input terminal wire colors .............................................................. 5-9

Power module wire colors .............................................................. 5-9

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

Ω

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

Performance

V eriﬁcation

1-2 Performance Veriﬁcation

Introduction

the limits stated in the instrument’s one-year accurac y speciﬁcations. Y ou can perform these ver iﬁcation procedures:

WARNING The information in this section is intended only for qualiﬁed service per-

Use the procedures in this section to verify that Model 2015 Multimeter accuracy is within

• When you ﬁrst receive the instrument to make sure that it w as not damaged during shipment, and that the unit meets factory speciﬁcations.

• If the instrument’s accuracy is questionable.

• Following calibration.

sonnel. 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

V eriﬁcation 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.

W arm-up period

Allow the Model 2015 Multimeter to warm up for at least one hour before conducting the v er-

iﬁcation 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.

Ω

1-4 Performance Veriﬁcation

Recommended test equipment

T able 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:

AC voltage

DC voltage

100mV:±14ppm

1.0V:±7ppm 10V:±5ppm 100V:±7ppm 1000V:±9ppm

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

(1kHz, 50kHz) DC current

100mV:±200ppm

1.0V:±82ppm 10V:±82ppm 100V:±90ppm 700V:±85ppm

10mA:±60ppm 100mA:±70ppm 1A:±110ppm

2.2A:±94ppm

AC current (1kHZ) Resistance

1A:±690ppm

2.2A:±682ppm

100

:±17ppm

:±12ppm

10k

:±11ppm

100k Ω :±13ppm 1M Ω :±18ppm 10M Ω :±37ppm 100M Ω :±120ppm

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.

V eriﬁcation 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:

Performance Veriﬁcation 1-5

Reading limits = 10V ± [(10V

Reading limits = 10V ± (.0003 + .00005)

Reading limits = 10V ± .00035V

Reading limits = 9.99965V to 10.00035V

30ppm) + (10V × 5ppm)]

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

2. Using either range key , select FACT , then restore the factory def ault conditions by press-

3. Factory defaults will be set as follows:

SHIFT and then SETUP . The instrument will display the following prompt:

RESTORE: FACT.

ing

ENTER .

Speed: medium Filter: 10 readings

Performance Veriﬁcation 1-7

Performing the veriﬁcation test procedures

T est 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.

T est 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 mak e 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

V erifying DC voltage

Check DC voltage accuracy by applying accurate v oltages from the DC v oltage 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 sho wn 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 ef fects. Connect the shield to the calibrator’ s output LO terminal.

Figure 1-1

Connections for DC volts verification

Model 2015

LOCAL

POWER

TALK LSTN SRQ SHIFT TIMER

MATH

SHIFT

DCV

EX TRIG

SAVE SETUP

SOURCE

THD

SCAN

CH1REM

STEP CH2 CH3 CH4 CH5 CH6 CH7 CH8 CH9 CH10

HOLD TRIG FAST MED SLOW AUTO ERR

REL FILT

dBm

DCI

LIMITS ON/OFFDELAY

STORE

CONFIG HALT

STEP SCAN

RECALL

CONT

ACI

DIGITS RATE

THD

ACV

HOLD

TRIG

MEAS

Ω2 Ω4

TEST

GPIB

CAL

RELFILTER

RS232

MATH REAR

BUFFER

STAT

2015 THD MULTIMETER

PERIOD TCOUPL

FREQ

TEMP

EXIT ENTER

RANGE

AUTO

350V PEAK

SENSE

Ω 4 WIRE

INPUTS

FRONT/REAR

Input HI

INPUT

3A 250V

AMPS

1000V

PEAK

500V PEAK

Output HI

Input

DC Voltage Calibrator

Output LO

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

* Source positive and negative values for each range.

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

1-10 Performance Veriﬁcation

V erifying AC voltage

Check AC voltage accuracy by applying accurate AC voltages at speciﬁc frequencies from the A C v oltage calibrator to the Model 2015 inputs and verifying that the displayed readings f all within speciﬁed ranges.

CAUTION Do not exceed 1100 V peak between INPUT HI and INPUT LO, or 8 × 10

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 A C voltage calibrator as sho wn in Figure 1-2.

Figure 1-2

Connections for AC volts verification

Note: Amplifier required only

for 700V, 50kHz output.

Model 2015

LOCAL

POWER

TALK LSTN SRQ SHIFT TIMER

MATH

SHIFT

DCV

EX TRIG

SAVE SETUP

SOURCE

THD

SCAN

CH1REM

STEP CH2 CH3 CH4 CH5 CH6 CH7 CH8 CH9 CH10

REL FILT

HOLD TRIG FAST MED SLOW AUTO ERR

dBm

DCI

LIMITS ON/OFFDELAY

STORE

CONFIG HALT

STEP SCAN

RECALL

CONT

ACI

Ω2 Ω4

TEST

GPIB

DIGITS RATE

THD

ACV

HOLD

TRIG

MEAS

RELFILTER

RS232

CAL

BUFFER

STAT

2015 THD MULTIMETER

PERIOD TCOUPL

FREQ

EXIT ENTER

MATH REAR

TEMP

RANGE

AUTO

RANGE

SENSE

INPUT

Ω 4 WIRE

350V

1000V

PEAK

500V PEAK

INPUTS

FRONT/REAR

3A 250V

AMPS

Shielded cable

Input HI

Output HI

Input LO

Output LO

AC Voltage Amplifier

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

100mV 1V 10V 100V 750V

* 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.

Applied AC voltage

100.0000mV

1.000000V

10.00000V

100.0000V

700.000V*

1kHz reading limits (1 year, 18°C-28°C)

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

50kHz reading limits (1 year, 18°C-28°C)

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

1-12 Performance Veriﬁcation

V erifying 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 v erifying that the displayed readings f all 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

LOCAL

POWER

STEP CH2 CH3 CH4 CH5 CH6 CH7 CH8 CH9 CH10

TALK

LSTN

SRQ SHIFT TIMER

HOLD TRIG FAST MED SLOW AUTO ERR

MATH

DCV

EX TRIG

SAVE SETUP

SOURCE

THD

ACV

HOLD

TRIG

MEAS

THD

SHIFT

DC Current Calibrator

Model 2015

SCAN

CH1REM

REL FILT

dBm

ACI

DCI

LIMITS ON/OFFDELAY

STORE

RECALL

CONFIG HALT

STEP SCAN

CONT

Ω2 Ω4

TEST

GPIB

DIGITS RATE

CAL

RELFILTER

RS232

MATH REAR

BUFFER

STAT

2015 THD MULTIMETER

PERIOD TCOUPL

FREQ

TEMP

EXIT ENTER

RANGE

SENSE

INPUT

Ω 4 WIRE

350V

PEAK

INPUTS

AUTO

FRONT/REAR

3A 250V

AMPS

1000V PEAK

500V PEAK

Input LO

Output HI

Amps

Output 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 negati ve 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.

V erifying AC current

Check AC current accuracy by applying accurate AC voltage current at speciﬁc frequencies from the A C current calibrator to the Model 2015 input and v erifying 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

SENSE

SHIFT

LOCAL

POWER

MATH

DCV

EX TRIG

SOURCE

TALK LSTN SRQ SHIFT TIMER

SAVE SETUP

THD

SCAN

CH1REM

STEP CH2 CH3 CH4 CH5 CH6 CH7 CH8 CH9 CH10

HOLD TRIG FAST MED SLOW AUTO ERR

dBm

THD

ACV

DCI

HOLD

LIMITS ON/OFFDELAY

TRIG

STORE

RECALL

CONFIG HALT

MEAS

STEP SCAN

BUFFER

REL FILT

CONT

ACI

Ω2 Ω4

TEST

CAL

RELFILTER

RS232

GPIB

DIGITS RATE

MATH REAR

STAT

2015 THD MULTIMETER

PERIOD TCOUPL

FREQ

TEMP

EXIT ENTER

RANGE

Ω 4 WIRE

350V PEAK

INPUTS

AUTO

FRONT/REAR

Amps

Performance Veriﬁcation 1-13

INPUT

3A 250V

AMPS

1000V PEAK

500V

PEAK

Output HI

Input LO

Output 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 Applied AC voltage Reading limits @ 1kHz (1 year, 18°C-28°C)

1A 3A

1.000000A

2.20000A

0.99860 to 1.00140A

2.1949 to 2.2051A

1-14 Performance Veriﬁcation

V erifying 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.

Ω

Figure 1-5

Connections for resistance verification (100

Sense HI

Model 2015

SENSE

LOCAL

POWER

STEP CH2 CH3 CH4 CH5 CH6 CH7 CH8 CH9 CH10

TALK

LSTN

SRQ SHIFT TIMER

HOLD TRIG FAST MED SLOW AUTO ERR

MATH

DCV

EX TRIG

SAVE SETUP

SOURCE

THD

ACV

HOLD

TRIG

MEAS

THD

SHIFT

SCAN

CH1REM

REL FILT

dBm

CONT

ACI

Ω2 Ω4

DCI

LIMITS ON/OFFDELAY

STORE

RECALL

CONFIG HALT

STEP SCAN

DIGITS RATE

MATH REAR

BUFFER

STAT

2015 THD MULTIMETER

PERIOD TCOUPL

FREQ

TEMP

TEST

CAL

RELFILTER

RS232

GPIB

EXIT ENTER

RANGE

Ω 4 WIRE

350V PEAK

INPUTS

AUTO

FRONT/REAR

Sense LO

2. Set the calibrator for 4-wire resistance with external sense on.

3. Select the Model 2015 4-wire resistance function by pressing the the SLOW integration rate with the RATE key.

4. Set the Model 2015 for the 100

5. Recalculate reading limits based on actual calibrator resistance values.

Ω

-10M

Ω

ranges)

Sense HI

INPUT

3A 250V

AMPS

Input HI

1000V PEAK

500V PEAK

Input LO

Output HI

Output LO

Resistance Calibrator

Sense LO

Note: Use shielded low-thermal cables to

minimize noise. Enable or disable calibrator external sense as indicated in procedure.

4 key, then choose

range, and make sure the FILTER is on.

6. Source the nominal full-scale resistance values for the 100 Ω -10M Ω 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

10. Source a nominal 100M Ω resistance value, and verify that the reading is within calculated limits for the 100M Ω range.

Figure 1-6

Connections for resistance verification (100M

Ω

range)

range.

Performance Veriﬁcation 1-15

Ω

1k Ω

Model 2015

Ω2 Ω4

TEST

GPIB

CAL

RELFILTER

RS232

MATH REAR

BUFFER

STAT

2015 THD MULTIMETER

PERIOD TCOUPL

FREQ

EXIT ENTER

TEMP

POWER

TALK LSTN SRQ SHIFT TIMER

MATH

SHIFT

DCV

LOCAL

EX TRIG

SAVE SETUP

SOURCE

THD

SCAN

CH1REM

STEP CH2 CH3 CH4 CH5 CH6 CH7 CH8 CH9 CH10

HOLD TRIG FAST MED SLOW AUTO ERR

REL FILT

dBm

DCI

LIMITS ON/OFFDELAY

STORE

CONFIG HALT

STEP SCAN

RECALL

CONT

ACI

DIGITS RATE

THD

ACV

HOLD

TRIG

MEAS

Sense LO

Table 1-6

Limits for resistance verification

Nominal

Range

100 Ω

resistance

100Ω 1kΩ

10k Ω 100kΩ 1MΩ 10MΩ 100MΩ

10kΩ 100kΩ 1MΩ 10MΩ 100MΩ

Sense HI

RANGE AUTO RANGE

SENSE

INPUT

Ω 4 WIRE

350V

PEAK

INPUTS

FRONT/REAR

3A 250V

AMPS

Input HI

1000V

PEAK

500V PEAK

Input LO

Output HI

Output LO

Resistance Calibrator

Note: Use shielded cables to minimize noise.

Disable calibrator external sense mode.

Nominal reading limits (1 year, 18°C-28°C) Recalculated limits*

99.9860 to 100.0140Ω

0.999890 to 1.000110kΩ

9.99890 to 10.00110kΩ

99.9890 to 100.0110kΩ

0.999890 to 1.000110MΩ

9.99590 to 10.00410MΩ

99.8470 to 100.1530MΩ

__________ to __________ Ω __________ to __________ kΩ __________ to __________ kΩ __________ to __________ kΩ __________ to __________ MΩ __________ to __________ MΩ __________ to __________ MΩ

* Calculate limits based on actual calibration resistance values and Model 2015 one-year accuracy

speciﬁcations. See Veriﬁcation limits.

1-16 Performance Veriﬁcation

V erifying 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. Howe ver, 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 sho wn 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 tempera-

ture: 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 temperature 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

* Voltages shown are based on ITS-90 standard using 0°C reference

junction temperature. See text for procedure to set reference junction temperature.

Applied DC voltage*

-7.659mV 0mV

42.280mV

-5.730mV 0mV

54.138mV

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

-190.6 to -189.4°C

-0.5 to +0.5°C

1349.2 to 1350.8°C

V erifying 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

Performance Veriﬁcation 1-17

SHIFT

LOCAL

POWER

TALK LSTN SRQ SHIFT TIMER

MATH

DCV

EX TRIG

SAVE SETUP

SOURCE

THD

Model 2015

SCAN

CH1REM

STEP CH2 CH3 CH4 CH5 CH6 CH7 CH8 CH9 CH10

REL FILT

CONT

Ω2 Ω4

TEST

GPIB

DIGITS RATE

BUFFER

PERIOD TCOUPL

FREQ

CAL

RELFILTER

RS232

HOLD TRIG FAST MED SLOW AUTO ERR

dBm

THD

ACI

ACV

DCI

HOLD

LIMITS ON/OFFDELAY

TRIG

STORE

RECALL

CONFIG HALT

MEAS

STEP SCAN

MATH REAR

STAT

2015 THD MULTIMETER

TEMP

EXIT ENTER

RANGE

BNC-to-Dual

Banana Plug

Frequency Synthesizer

Adapter

SENSE

INPUT

Ω 4 WIRE

350V

1000V

PEAK

500V PEAK

INPUTS

AUTO

FRONT/REAR

3A 250V

AMPS

Main

Function

Output

50Ω BNC Coaxial Cable

1-18 Performance Veriﬁcation

V erifying 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

BNC-to-Dual

Banana Plug

Adapter

INPUT

1000V

PEAK

500V PEAK

3A 250V

AMPS

SHIFT

LOCAL

POWER

TALK LSTN SRQ SHIFT TIMER

MATH

DCV

EX TRIG

SAVE SETUP

SOURCE

THD

Model 2015

SCAN

CH1REM

STEP CH2 CH3 CH4 CH5 CH6 CH7 CH8 CH9 CH10

REL FILT

HOLD TRIG FAST MED SLOW AUTO ERR

dBm

THD

ACV

DCI

HOLD

LIMITS ON/OFFDELAY

TRIG

STORE

RECALL

CONFIG HALT

MEAS

STEP SCAN

BUFFER

CONT

PERIOD TCOUPL

Ω2 Ω4

TEST

GPIB

DIGITS RATE

FREQ

CAL

RELFILTER

RS232

ACI

MATH REAR

STAT

2015THD MULTIMETER

TEMP

EXIT ENTER

RANGE

SENSE

Ω 4 WIRE

350V PEAK

INPUTS

AUTO

FRONT/REAR

Low Distortion Function Generator

Output

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: AUT O 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%.

V erifying 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

Performance Veriﬁcation 1-19

POWER

TALK LSTN SRQ

SHIFT

TIMER

MATH

SHIFT

DCV

LOCAL

EX TRIG

SAVE SETUP

SOURCE

THD

Model 2015

SCAN

CH1REM

STEP CH2 CH3 CH4 CH5 CH6 CH7 CH8 CH9 CH10

REL FILT

HOLD TRIG FAST MED SLOW AUTO ERR

dBm

THD

ACV

DCI

HOLD

LIMITS ON/OFFDELAY

TRIG

STORE

RECALL

CONFIG HALT

MEAS

STEP SCAN

BUFFER

CONT

Ω2 Ω4

TEST

GPIB

DIGITS RATE

RS232

RELFILTER

PERIOD TCOUPL

CAL

ACI

MATH REAR

STAT

2015 THD MULTIMETER

FREQ

TEMP

EXIT ENTER

RANGE

SENSE

INPUT

Ω 4 WIRE

350V

1000V

PEAK

500V PEAK

INPUTS

AUTO

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.

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 per-

sonnel. 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 A C currents, and resistance values. Comprehensi ve 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

W arm-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 e xtra 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 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 a v ailable 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 do wn 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.

Calibration 2-5

Remote calibration code

If you are performing calibration over the IEEE-488 bus or the RS-232 port, send this com-

mand to unlock calibration:

:CAL:PROT:CODE '<8-character string>'.

The default code command is:

:CAL:PROT:CODE 'KI002015'.

Ω

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

Calibration cycle

Perform comprehensive calibration at least once a year, or every 90 days to ensure the unit meets the corresponding speciﬁcations.

Manufacturing calibration at the end of this section for more information.

Recommended equipment

T able 2-1 lists the recommended equipment you need for comprehensive, DC only, A C 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:

AC voltage

DC voltage

10V:±5ppm 100V: ±ppm

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, 50kHz)* DC current

10mV:±710ppm 100mV:±200ppm 1V:±82ppm 10V:±82ppm 100V:±90ppm 700V:±85ppm

10mA:±60ppm 100mA:±70ppm 1A:±110ppm

AC current (1kHz) Resistance

100mA:±190ppm 1A:±690ppm 2A:±670ppm

1k 10k 100k 1M

:±12ppm

:±11ppm

:±13ppm

:±18ppm

* 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.

Aborting calibration

You can abort the front panel calibration process at any time by pressing EXIT. The instru-

ment 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.

Calibration 2-7

Front panel calibration

Follow the steps in the following paragraphs for comprehensive, DC only, AC only, distor-

tion, 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 allo w 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 do wn 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 b utton 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

INPUT

1000V

PEAK

500V PEAK

3A 250V

AMPS

Model 8610 Low-thermal

short

LOCAL

POWER

TALK LSTN SRQ SHIFT TIMER

MATH

SHIFT

DCV

EX TRIG

SAVE SETUP

SOURCE

THD

Model 2015

SCAN

CH1REM

STEP CH2 CH3 CH4 CH5 CH6 CH7 CH8 CH9 CH10

HOLD TRIG FAST MED SLOW AUTO ERR

dBm

THD

ACI

ACV

DCI

HOLD

LIMITS ON/OFFDELAY

TRIG

STORE

RECALL

CONFIG HALT

MEAS

STEP SCAN

BUFFER

REL FILT

CONT

PERIOD TCOUPL

FREQ

Ω2 Ω4

TEST

CAL

RELFILTER

RS232

GPIB

DIGITS RATE

MATH REAR

STAT

2015 THD MULTIMETER

TEMP

EXIT ENTER

RANGE

S+

SENSE

Ω 4 WIRE

350V

PEAK

INPUTS

AUTO

FRONT/REAR

S-

NOTE Be sure to connect the low-thermal short properly to the HI, LO, and SENSE termi-

nals. Keep drafts away from low-thermal connections to avoid thermal drift, which could affect calibration accuracy.

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 volts calibration

After the front panel short and open procedure, the unit will prompt you for the ﬁrst DC volt-

age: +10V. Do the following:

Calibration 2-9

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

Sense HI

Model 2015

SENSE

INPUT

Ω 4 WIRE

350V

PEAK

INPUTS

FRONT/REAR

3A 250V

AMPS

LOCAL

POWER

TALK

LSTN

SRQ SHIFT TIMER

MATH

SHIFT

DCV

EX TRIG

SAVE SETUP

SOURCE

THD

SCAN

CH1REM

STEP CH2 CH3 CH4 CH5 CH6 CH7 CH8 CH9 CH10

HOLD TRIG FAST MED SLOW AUTO ERR

dBm

THD

ACI

ACV

DCI

HOLD

LIMITS ON/OFFDELAY

TRIG

STORE

RECALL

CONFIG HALT

MEAS

STEP SCAN

BUFFER

REL FILT

CONT

PERIOD TCOUPL

Ω2 Ω4

TEST

CAL

RELFILTER

RS232

GPIB

DIGITS RATE

MATH REAR

STAT

2015 THD MULTIMETER

FREQ

TEMP

EXIT ENTER

RANGE

AUTO

Sense LO

NOTE Although 4-wire connections are shown, the sense leads are connected and discon-

nected 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 of f, and connect the sense leads when external sensing is to be turned on.

Sense HI

DC Voltage Calibrator

Input HI

1000V PEAK

500V PEAK

Input LO

Output HI

Output 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 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 T able 2-3, use the left and

right arrow ke ys, and the up and down rang e keys to set the Model 2015 display value to match the calibrator output voltage.

Table 2-3

DC volts calibration summary

Calibration step

+10V

-10V 100V

Calibrator voltage Allowable range

+10.00000V

-10.00000V +100.0000V

+9V to +11V

-9V to -11V +90V to +110V

Resistance calibration

Completing the 100V DC calibration step ends the DC voltage calibration procedure. The

Model 2015 will then prompt you to connect 1k

1. Set the calibrator output for resistance, and turn on external sense.

Ω

1k Ω

1M Ω 1k Ω

1M Ω

9k Ω

Calibration 2-11

. Follow these steps for resistance calibration:

NOTE Use external sense (4-wire

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 step

Calibrator resistance* Allowable range

Ω

) when calibrating all resistance r anges. Be sur e that the

0.9k Ω to 1.1k Ω 10k Ω 100k Ω

10k Ω 100k Ω

to 11k Ω

90k Ω to 110k Ω

0.9M Ω to 1.1M Ω

* Nominal resistance. Adjust Model 2015 calibration

parameter to agree with actual value.

2-12 Calibration

DC current calibration

After the 1M Ω resistance point has been calibrated, the unit will prompt you for 10mA. Fol-

low 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

SENSE

Ω 4 WIRE

350V

PEAK

INPUTS

AUTO

FRONT/REAR

LOCAL

POWER

STEP CH2 CH3 CH4 CH5 CH6 CH7 CH8 CH9 CH10

TALK

LSTN

SRQ SHIFT TIMER

HOLD TRIG FAST MED SLOW AUTO ERR

MATH

THD

SHIFT

DCV

ACV

HOLD

TRIG

EX TRIG

SAVE SETUP

SOURCE

MEAS

THD

SCAN

CH1REM

REL FILT

dBm

CONT

ACI

Ω2 Ω4

DCI

LIMITS ON/OFFDELAY

STORE

RECALL

CONFIG HALT

STEP SCAN

DIGITS RATE

MATH REAR

BUFFER

STAT

2015 THD MULTIMETER

PERIOD TCOUPL

FREQ

TEMP

EXIT ENTER

RANGE

TEST

CAL

RELFILTER

RS232

GPIB

Current Calibrator

Input

1000V PEAK

500V PEAK

Output HI

INPUT

3A 250V

AMPS

Amps

Output 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

Calibrator

Calibration step

10mA 100mA 1A

current Allowable range

10.00000mA

100.0000mA

1.000000A

9mA to 11mA 90mA to 110mA

0.9A to 1.1A

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

LOCAL

POWER

TALK

LSTN

SRQ SHIFT TIMER

MATH

SHIFT

DCV

EX TRIG

SAVE SETUP

SOURCE

THD

SCAN

CH1REM

STEP CH2 CH3 CH4 CH5 CH6 CH7 CH8 CH9 CH10

HOLD TRIG FAST MED SLOW AUTO ERR

REL FILT

dBm

DCI

LIMITS ON/OFFDELAY

STORE

CONFIG HALT

STEP SCAN

RECALL

CONT

ACI

DIGITS RATE

THD

ACV

HOLD

TRIG

MEAS

Ω2 Ω4

TEST

GPIB

CAL

RELFILTER

RS232

MATH REAR

BUFFER

STAT

2015 THD MULTIMETER

PERIOD TCOUPL

FREQ

TEMP

EXIT ENTER

RANGE

AUTO

RANGE

Calibration 2-13

Input HI

SENSE

INPUT

Ω 4 WIRE

350V

PEAK

INPUTS

FRONT/REAR

3A 250V

AMPS

1000V PEAK

500V PEAK

Output HI

Input

AC Voltage Calibrator

Output LO

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 Calibrator voltage, frequency

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

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 Calibrator current, frequency

100mA at 1kHz 1A at 1kHz 2A at 1kHz

Distortion calibration

1. Following A C 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.

100.0000mA, 1kHz

1.000000A, 1kHz

2.000000A, 1kHz

Figure 2-5

Connections for distortion calibration

Calibration 2-15

Model 2015

SENSE

LOCAL

POWER

STEP CH2 CH3 CH4 CH5 CH6 CH7 CH8 CH9 CH10 TALK LSTN SRQ SHIFT TIMER

HOLD TRIG FAST MED SLOW AUTO ERR

MATH

THD

SHIFT

DCV

ACV

HOLD

EX TRIG

TRIG

SAVE SETUP

SOURCE

MEAS

THD

Ω2 Ω4

TEST

GPIB

CAL

RELFILTER

RS232

MATH REAR

BUFFER

STAT

2015 THD MULTIMETER

PERIOD TCOUPL

FREQ

EXIT ENTER

TEMP

SCAN

CH1REM

REL FILT

dBm

CONT

ACI

DCI

LIMITS ON/OFFDELAY

STORE

RECALL

CONFIG HALT

STEP SCAN

DIGITS RATE

RANGE

Ω 4 WIRE

350V

PEAK

INPUTS

AUTO

FRONT/REAR

Table 2-8

Distortion and function generator calibration summary

Calibration step Calibration signal or connections

Distortion, 1V at 137Hz Distortion, 1V at 844Hz Function generator

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.

INPUT

3A 250V

AMPS

BNC-to-Dual

Banana Plug

Adapter

1000V PEAK

500V PEAK

Low Distortion Function Generator

Output

Coaxial Cable

1V RMS, 137Hz sine wave 1V RMS, 844Hz sine wave SOURCE OUTPUT to INPUT

Figure 2-6

Connections for function generator calibration

Model 2015

Ω2 Ω4

TEST

GPIB

CAL

RELFILTER

RS232

MATH REAR

BUFFER

STAT

2015 THD MULTIMETER

PERIOD TCOUPL

FREQ

TEMP

EXIT ENTER

POWER

TALK LSTN SRQ

SHIFT

TIMER

MATH

SHIFT

DCV

LOCAL

EX TRIG

SAVE SETUP

SOURCE

THD

SCAN

CH1REM

STEP CH2 CH3 CH4 CH5 CH6 CH7 CH8 CH9 CH10

HOLD TRIG FAST MED SLOW AUTO ERR

REL FILT

dBm

DCI

LIMITS ON/OFFDELAY

STORE

CONFIG HALT

STEP SCAN

RECALL

CONT

ACI

DIGITS RATE

THD

ACV

HOLD

TRIG

MEAS

RANGE

Connect INPUT jacks to

SENSE

INPUT

Ω 4 WIRE

350V

1000V

PEAK

500V PEAK

INPUTS

AUTO

FRONT/REAR

3A 250V

AMPS

rear panel SOURCE OUTPUT

2-16 Calibration

Setting calibration dates and saving calibration

Remote 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 curr ent calibr ation procedur e will not be

saved unless you choose the YES option. Previous calibration constants will be retained if you select NO.

Follow the steps in this section to perform comprehensi ve procedures via remote. See Appen-

dix 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 fr ont panel calibr ation, you can c hoose to perform comprehensive, DC-only,

AC-only, distortion, or function generator calibration. Be sure to include a space character between each command and parameter.

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

Calibration 2-17

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 b utton is not pressed in so that the front inputs are active. W ait at least three minutes before proceeding to allo w for thermal equilibrium.

NOTE Be sure to connect the low-thermal short properly to the HI, LO, and SENSE termi-

nals. 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 volts calibration

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 discon-

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 step

+10V

-10V 100V

* Use recommended value where possible. Change parameter accordingly if using a

different calibrator voltage.

Calibrator voltage Calibration command* Parameter range

+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

Resistance calibration

Follow these steps for resistance calibration:

1. Set the calibrator to the resistance mode, and turn on external sensing.

Calibration 2-19

NOTE Use external sense (4-wir e

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 step

1kΩ 10kΩ 100kΩ 1MΩ

* Use exact calibrator resistance value for parameter.

Calibrator resistance Calibration command* Parameter range

1kΩ 10kΩ 100kΩ 1MΩ

Ω

) when calibrating all resistance r anges. Be sur e that the

:CAL:PROT:DC:STEP6 1E3 :CAL:PROT:DC:STEP7 10E3 :CAL:PROT:DC:STEP8 100E3 :CAL:PROT:DC:STEP9 1E6

900 to 1.1E3 9E3 to 11E3 90E3 to 110E3 900E3 to 1.1E6

2-20 Calibration

DC current calibration

After the 1MΩ 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 step

10mA 100mA 1A

* Change parameter if using different current.

Calibrator current Calibration command* Parameter range

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

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

Calibration 2-21

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 Calibrator current, frequency Calibration command

100mA at 1kHz 1A at 1kHz 2A at 1kHz

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 Distortion, 1V at 844Hz Function generator

100.0000mA, 1kHz

1.000000A, 1kHz

2.000000A, 1kHz

1V RMS, 137Hz sine wave 1V RMS, 844Hz sine wave SOURCE OUTPUT to INPUT

:CAL:PROT:AC:STEP11 :CAL:PROT:AC:STEP12 :CAL:PROT:AC:STEP13

:CAL:PROT:DIST:STEP1 :CAL:PROT:DIST:STEP2 :CAL:PROT:FGEN:STEP1

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

Calibration 2-23

Saving calibration constants

After completing the calibration procedure, send the following command to sa ve the ne w cal-

ibration 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.

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 (def ault:

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

BNC-to-Dual

Banana Plug

Adapter

INPUT

1000V

PEAK

500V

PEAK

3A 250V

AMPS

POWER

TALK

LSTN

SRQ SHIFT TIMER

MATH

SHIFT

DCV

LOCAL

EX TRIG

SAVE SETUP

SOURCE

THD

Model 2015

SCAN

CH1REM

STEP CH2 CH3 CH4 CH5 CH6 CH7 CH8 CH9 CH10

REL FILT

HOLD TRIG FAST MED SLOW AUTO ERR

dBm

THD

ACV

DCI

HOLD

LIMITS ON/OFFDELAY

TRIG

STORE

RECALL

CONFIG HALT

MEAS

STEP SCAN

BUFFER

CONT

PERIOD TCOUPL

Ω2 Ω4

TEST

GPIB

DIGITS RATE

FREQ

CAL

RELFILTER

RS232

ACI

MATH REAR

STAT

2015 THD MULTIMETER

TEMP

EXIT ENTER

RANGE

SENSE

Ω 4 WIRE

350V PEAK

INPUTS

AUTO

FRONT/REAR

Calibration 2-25

Model 3930A or 3940 Synthesizer

Main

Function

Output

50Ω BNC Coaxial Cable

Note: Synthesizer output voltage

must be accurately measured. (See text)

8. After the last A C 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 k eys 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

Routine

Maintenance

3-2 Routine Maintenance

Introduction

Setting the line voltage and replacing the line fuse

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.

WARNING Disconnect the line cord at the rear panel, and remove all test leads con-

nected 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 screwdriv er into the po wer 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, remo ve 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.

WARNING:NO INTERNAL OPERATOR SERVICABLE PARTS,SERVICE BY QUALIFIED PERSONNEL ONLY.

CAUTION:FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,REPLACE FUSE WITH SAME TYPE AND RATING.

Routine Maintenance 3-3

Figure 3-1

Power module

Model 2015

350V PEAK

SOURCE OUTPUT

1000V

TRIGGER

PEAK

500V PEAK

INPUT

SENSE

Ω 4W

42V PEAK

INV/PULSE

SOURCE OUTPUT

3 5

4 6

FUSE LINE

100 VAC

500 mAT

120 VAC

(SB)

220 VAC

250 mAT

240 VAC

(SB)

LINK

VMC EXT TRIG

LINE RATING

50, 60Hz

40VA MAX

MADE IN

U.S.A.

RS232

IEEE-488

(CHANGE IEEE ADDRESS

FROM FRONT PANEL)

120

Fuse

Spring

Table 3-1

Power line fuse

Line Voltage Rating Keithley Part No.

100/120V 1/2A, 250V, 5 × 20 mm, slow-blow FU-71 200/240V 1/4A, 250V, 5 × 20 mm, slow-blow FU-96-4

Replacing the AMPS fuse

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.

120

Line Voltage Selector

Window

Fuse Holder Assembly

3-4 Routine Maintenance

CAUTION Do not use a fuse with a higher current rating than speciﬁed, or instrument

4. Install the new fuse by reversing the above procedure.

damage may occur . If the instrument repeatedly blows fuses, locate and correct the cause of the trouble before replacing the fuse.

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 person-

nel. 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 spe-

cialized 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

• 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

• Many CMOS devices are installed in the Model 2015. These static-sensitive devices require special handling as explained in

• 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.

Section 5 of this manual.

Section 5 .

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.

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 bleshooting 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 ke y is pressed, the label name for that key is displayed 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.

Troubleshooting 4-5

Display board checks for details on trou-

DISP test

rescent display is working properly. Perform the following steps to run the display test:

The display test allows you to verify that each segment and annunciator in the vacuum ﬂuo-

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

Power Switch

Line

Voltage

Switch

Power

Transformer

Power

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 ﬁ laments 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 man y 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 Rectiﬁer Filter Regulator

+5VD +37V +15V

-15V +5V, +5VRL +5VD2 +15VF

-15VF +5VF

CR104 CR116, CR117 CR102 CR102 CR103 CR301 CR330 CR330 CR331

C128, C156 C104, C106 C148 C131 C146 C350 C562 C565 C568

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

Analog

Circuitry

(See Figure 4-3)

Scan Control

XADTX XADCLK XADTS

XADRX

Trigger

U146, U164

Trigger

Link

NVRAM

P T

AT101

U150 U155

U136

ADTX ADCLK ADTS

ADRXB

TRIG IN TRIG OUT

ROM

U156, U157

68306

µP

U135

ROM

U156, U157

OUT

TDTX TDCLK TDTS XTDRX

Display Board

Controller

U401

XTAL Y101

RS-232

U159

GPIB

U158, U160,

U161

Distortion

Digital Circuit

(See Figure 4-4)

Keypad

Display

DS401

RS-232

Port

IEEE-488

Bus

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 k ey is read by strobing the columns and reading all rows for each strobed column. K ey-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 b us. 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.

T rigger circuits

Buffering for Trigger Link input and output is performed by U146. T rigger 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 T rigger Link connector (resistor R270 installed).

Analog circuitry

Refer to Figure 4-3 for the following discussion on analog circuitry.

Figure 4-3

Analog circuitry block diagram

AMPS

Troubleshooting 4-11

INPUT

R117, Q109,

Q114, Q136

SENSE

Current

Shunts

K103, R158, R205

ACV,

FREQ

SSP* Q101, Q102

DCV

Divider

* Solid State Protection

Ohms I-Source

U133, Q123, Q125, Q124, Q126, Q119,

Q120, U123

DCV/100

X1 Buffer

Q121, U126

DCA

ACA

AC Switching

DCV

OHMS

Gain

DCV & Ohms

Switching

K101, Q104,

Q105, Q108,

Q113, U115

K102, U102, U103, U105, U112, U118, U111, U110

Buffer

U113

BUFCOM

Scanner

Output

Scanner

Inputs

A/D

MUX &

Gain U163, U166 U129, U132

Scanner

Option

ADC

U165

Scanner Control

Distortion

Analog

Circuitry

(See Figure 4-5)

Digital

Circuitry

(See Figure 4-2)

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

AMPS input

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 input. Relay K103 is energized (on) to select the shunts. For all other DCA ranges, and all ACA ranges, 0.1

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).

Ω

(R158 + R205) is shunted across the

(R158) is shunted across the input (K103 off).

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 v ary 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.

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

OSC

Troubleshooting 4-13

ROM U330

T A G

DSP

U329

DIGITAL

(See Figure 4-2)

FPGA

U327

TDTX

TDCLK

TDTS

TDVAL

U312, U313, U316, U317, U318, U319

OPTO ISO

XTDTS

XTDVAL

DISTORTION

ANALOG

CIRCUITRY

(See Figure 4-5)

XTDCLK

XTDTX

FDTS

XFDTS

FDTX

FDCLK

OPTO ISO

XFDCLK

XFDTX

SINEGEN

CIRUITRY

(See Figure 4-6)

EEPROM

U326

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 D A C conv erters. 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.

Distortion analog circuitry

Refer to Figure 4-5 for the following discussion on distortion analog circuitry.

Figure 4-5

Distortion analog circuitry block diagram

Troubleshooting 4-15

Analog

Circuitry

(See Figure 4-3)

ADC Converter

U311

Distortion

Digital

Circuitry

(See Figure 4-4)

EEPROM

U315

OSC

Y301

Amplifier Filter

U309, U310

ADC Clock

Generator

U325

FPGA U314

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 frequenc y 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

OSC

Sine Generator U301

Distortion Digital Circuitry

(see Figure 4-4)

Attenuator U303, U334 U335

FPGA

Inv-Sine/pulse

Filter U307

EEPROM

-1

Comparator

U305 U306 U307 U308

K301 50/600 Ohm

Inv Sine/ Pulse Out

Source Output

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 wav e output amplitude. The output amplitude is set by the microprocessor through the FPGA, U334, and the opto-isolators U304, U320, and U321.

Ω

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 cutof f 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 w ave output. Another IC selects whether the sinewave or the comparator is fed to the output.

K301 selects between either 50

or 600 Ω output impedance.

4-18 Troubleshooting

T roubleshooting

Troubleshooting information for the v arious 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 2 3 4

5 6 7

Front panel DISP test. P1005, PIN 5 P1005, PIN 9 U401, PIN 1

U401, PIN43 U401, PIN 32 U401, PIN 33

Verify that all segments operate. +5V ±5% +37V ±5% Goes low brieﬂy on power up, then goes high. 4MHz square wave. Pulse train every 1msec. Brief pulse train when front panel key is pressed.

Use front panel display test. Digital +5V supply. Display +37V supply. Microcontroller RESET.

Controller 4MHz clock. Control from main processor.

Key down data sent to main processor.

Power supply checks

Power supply problems can be checked out using Table 4-3.

Table 4-3

Power supply checks

Step Item/component Required condition Remarks

Troubleshooting 4-19

1 2 3

4 5 6 7 8 9 10 11 12

Line fuse Line voltage Line power

U144, pin 2 U101, pin 7 U125, pin 3 U119, pin 3 U124, pin 3 U331, pin 2 U348, pin 3 U349, pin 3 U350, pin 3

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%

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 Required condition Remarks

3 4

5 6 7 8 9 10

11 12 13 14 15 16 17

Power-on test

U152 pin 14

U152 pin 28 U135 pin 48

U135, lines A1-A23 U135, lines D1-D15 U135 pin 44 U159 pin 13 U159 pin 14 U158 pins 34-42

U158 pins 26-31 U158 pin 24 U158 pin 25 U135 pin 84 U135 pin 91 U135 pin 90 U135 pin 89

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.

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 Q114 Q136 Q109 K101* Q113 Q105 Q104 Q108 Q121

100mV 1V 10V 100V 1000V

* K101 set states:

Table 4-6

ACV and FREQ signal switching

ON ON ON OFF OFF

OFF OFF OFF ON ON

Pin 8 switched to Pin 7 Pin 3 switched to Pin 4

OFF OFF OFF ON ON

Range Q101 Q102 K101* K102*

100mV 1V 10V 100V 750V

* K101 and K102 reset states:

ON ON ON ON ON

RESET RESET RESET RESET RESET

K101 and K102 set states:

RESET RESET SET SET SET

Pin 8 switched to Pin 9 Pin 3 switched to Pin 2 Pin 8 switched to Pin 7 Pin 3 switched to Pin 4

U103 pin 8

ON ON OFF OFF OFF

OFF OFF OFF OFF OFF

U103 pin 9

ON ON OFF OFF OFF

SET SET SET SET SET

U105 pin 9

OFF OFF ON ON ON

OFF OFF OFF OFF OFF

U105 pin 8

OFF OFF OFF OFF ON

OFF OFF OFF OFF OFF

U103 pin 16

OFF ON OFF ON OFF

ON ON ON OFF OFF

U103 pin 1

ON OFF ON OFF OFF

OFF OFF OFF ON ON

U105 pin 1

ON OFF ON OFF OFF

ON ON ON ON ON

U111 pin 16

OFF OFF OFF OFF OFF

4-22 Troubleshooting

Table 4-7

Ω

2 signal switching

Range Q101 Q102 Q114 Q136 Q109 K101* K102* Q113 Q105 Q104 Q108 Q121

1k Ω

100 Ω

10k Ω 100k Ω

10MΩ 100MΩ

* K101 set states:

Table 4-8

Ω

ON ON ON ON

Ω

ON ON ON

K102 reset states:

4 signal switching

ON ON ON ON ON ON ON

OFF OFF OFF OFF OFF OFF OFF

Pin 8 switched to Pin 7 Pin 3 switched to Pin 4 Pin 8 switched to Pin 9 Pin 3 switched to Pin 2

OFF OFF OFF OFF OFF ON ON

SET SET SET SET SET SET SET

RESET RESET RESET RESET RESET RESET RESET

OFF OFF OFF OFF OFF OFF OFF

ON ON ON ON ON ON ON

OFF OFF OFF OFF OFF OFF OFF

ON ON ON ON ON ON ON

Range Q101 Q102 Q114 Q136 Q109 K101* Q113 Q105 Q104 Q108 Q121

100Ω 1kΩ 10kΩ 100kΩ 1MΩ 10MΩ 100MΩ

ON ON ON ON ON ON ON

OFF OFF OFF OFF OFF OFF OFF

OFF OFF OFF OFF OFF ON ON

SET SET SET SET SET SET SET

ON ON ON ON ON OFF OFF

OFF OFF OFF OFF OFF ON ON

OFF OFF OFF OFF OFF OFF OFF

ON ON ON ON ON ON ON

*K101 set states:

Table 4-9

Ω

4 reference switching

Pin 8 switched to Pin 7 Pin 3 switched to Pin 4

Range U133/0.7 U133/7V Q123 Q125 Q124 Q126 Q120

100Ω 1kΩ 10kΩ 100kΩ 1MΩ 10MΩ 100MΩ

OFF OFF OFF ON ON OFF OFF

ON ON ON OFF OFF ON ON

ON ON OFF OFF OFF OFF OFF

OFF OFF ON ON ON ON ON

ON ON ON ON ON OFF OFF

Table 4-10

DCA signal switching

Range K103

Troubleshooting 4-23

10mA 100mA 1A 3A

Table 4-11

ACA signal switching

Range K103

1A 3A

Table 4-12

DCV signal multiplexing and gain

Range

ON OFF OFF OFF

U105 pin 16

OFF OFFONON

T ables 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).

Signal (U163)

U105 pin 1

ON ON

U129 pin 1

U111 pin 16

OFFONOFF

U129 pin 8

U129 pin 9

U105 pin 8

OFF

U103 pin 16

OFF OFF

Gain (U166)

U103 pin 1

OFF OFF

100mV 1V 10V 100V 1000V

Table 4-13

ACV and ACA signal multiplexing and gain

Range

S4 S4 S4 S4 S4

Signal (U163)

OFF OFF ON OFF ON

U129 pin 1

OFF ON OFF ON OFF

U129 pin 8

ON OFF OFF OFF OFF

U129 pin 9

All S3 ON OFF OFF ×1

×100 ×10 ×1 ×10 ×1

Gain (U166)

4-24 Troubleshooting

Table 4-14

DCA signal multiplexing and gain

Signal

Range

10mA 100mA 1A 3A

Table 4-15

Ω

2 signal multiplexing and gain

(U163)

S6 S6 S6 S6

Signal

Range

100Ω 1kΩ 10kΩ 100kΩ 1MΩ 10MΩ 100MΩ

Table 4-16

Ω

4 signal multiplexing and gain

(U163)

S4 S4 S4 S4 S4 S4 S4

U129 pin 1

OFF OFF OFF OFF

U129 pin 1

OFF OFF OFF OFF ON ON ON

U129 pin 8

OFF OFF OFF ON

U129 pin 8

OFF ON ON ON OFF OFF OFF

U129 pin 9

ON ON ON OFF

U129 pin 9

ON OFF OFF OFF OFF OFF OFF

Gain (U166)

×100 ×100 ×100 ×10

Gain (U166)

×100 ×10 ×10 ×10 ×1 ×1 ×1

Range

100Ω 1kΩ 10kΩ 100kΩ 1MΩ 10MΩ 100MΩ

Signal (U163)

S4 then S7 S4 then S7 S4 then S7 S4 then S7 S4 then S7 S4 then S7 S4 then S7

U129 pin 1

OFF OFF OFF OFF ON ON 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 Analog circuit section (see Figure 4-3)

Q101, Q102 Q114, Q136, Q109 K101, Q113, Q105, Q104, Q108 Q121 K102, U103, U105, U111 U133, Q120, Q123, Q124, Q125, Q126 K103 U129, U163

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

Disassembly

5-2 Disassembly

Introduction

This section explains how to handle, clean, and disassemble the Model 2015 Multimeter. Dis-

assembly drawings are located at the end of this section.

Disassembly 5-3

Handling and cleaning

T o 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 remov ed the ﬂux, swab only the repair area with methanol, then blo w 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 Disassembly

Static sensitive devices

you or your clothing may be sufﬁcient to destroy these de vices if the y are not handled properly. Use the following precautions to avoid damaging them:

CAUTION Many CMOS devices are installed in the Model 2015. Handle all semicon-

CMOS devices operate at very high impedance le vels. Therefore, an y static that builds up on

ductor 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.

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

Disassembly 5-5

5-6 Disassembly

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 do wn. 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. W ith the arro ws lined up, pull the ends of the handle a way from the case.

2. Remove Mounting Ears — Remov e the screw that secures each mounting ear . Pull do wn 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. Eac h 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 — Remov e the two grounding scre ws that secure the case to the chassis. They are located on the bottom of the case at the back.

5. Remove Cover — T o 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.

Disassembly 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. T o remo ve 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 tow ards 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 jacks on the rear panel.

2. Unplug cables:

• Unplug the power entry module cable, J1021.

• Unplug the transformer primary connections, J1018 and J1019.

• Unplug the transformer cable from J1020.

• Unplug the DMM board connectors, J1022, J1024, and J1026.

• Unplug the transformer cable, J1031.

3. Remove all seven screws that secure the DSP board to the chassis.

4. Slide the board toward the front of the chassis until the BNC jacks ha ve cleared the chassis and the board is clear of the guide pins, then remove the board.

During re-assembly, replace the board by lining up the guide pins over the slots, then slide the board toward the rear. Loosely install all screws, then install and tighten the BNC jack nuts. Tighten all screws.

5-8 Disassembly

Front panel disassembly

NOTE You must ﬁrst remove the case cover, the front/rear input switch, and the front input

Use the following procedures to remov e the display board and/or the pushbutton switch pad:

terminal wires as described earlier in this section.

1. Unplug the display board ribbon cable from connector J1014.

2. Remove the front panel assembly. This assembly has four retaining clips that snap onto the chassis over four pem nut studs.

Two retaining clips are located on each side of the front panel. Pull the retaining clips outward and, at the same time, pull the front panel assembly forward until it separates from the chassis.

3. Using a thin-bladed screw driv er , pry the plastic PC board stop (located at the bottom of the display board) until the bar separates from the casing. Pull the display board from the front panel.

4. Remove the switch pad by pulling it from the front panel.

Removing power components

The following procedures to remove the po wer transformer and/or po wer module require that

the case cover and motherboard be removed, as previously explained.

Power transformer removal

Perform the following steps to remove the power transformer:

1. Remove the DMM board.

2. Unplug the transformer wires that attach to the DSP board:

• For TR-332, unplug J1018 and J1020.

• For TR-328, unplug J1019 and J1031.

3. Remove the two nuts that secure the transformer to the bottom of the chassis.

4. Pull the black ground wire off the threaded stud, and remov e the power transformer from the chassis.

Power module removal

Perform the following steps to remove the power module:

1. Remove the DMM board.

2. Unplug connector J1021 from the DSP board.

3. Disconnect the power module's ground wire. This green and yellow wire connects to a threaded stud on the chassis with a kep nut.

4. Squeeze the latches on either side of the power module while pushing the module from the access hole.

Instrument reassembly

Reassemble the instrument by reversing the pre vious disassembly procedures. Make sure that all parts are properly seated and secured, and that all connections are properly made. To ensure proper operation, replace and securely fasten the shield.

WARNING To ensure continued protection against electrical shock, verify that power

line ground (green and yellow wire attached to the power module) and the power transformer ground (black wire) are connected to the chassis. When installing the power transformer, be sure to re-connect the black ground wire to the mounting stud on bottom of the chassis. Be sure to install the bottom case screws to assure a good case-to-chassis ground connection.

Disassembly 5-9

Input terminal wire connections

During reassembly, use the information in Table 5-1 to connect input terminal wires.

Table 5-1

Input terminal wire colors

Input terminal Front wire color Rear wire color

INPUT HI INPUT LO SENSE HI SENSE LO AMPS

Red Black Yellow Gray White

Power module wire connections

Use the information in T able 5-2 and DETAIL B of drawing 2015-050 to connect power module wires.

Table 5-2

Power module wire colors

Location Wire color

White/Red White/Black White/Yellow White/Gray —

Top wire Right top Right bottom Left top Left bottom

Gray Violet White Red Blue

5-10 Disassembly

Changing trigger link lines

The Model 2015 uses two lines of the T rigger Link rear panel connector as External Trigger (EXT TRIG) input and Voltmeter Complete (VMC) output. At the factory, line 1 is conﬁgured as VMC and line 2 as EXT TRIG.

NOTE Line 1, 3, or 5 of the T rigger Link can be conﬁ gur ed as VMC, while line 2, 4, or 6 can

be conﬁgured as EXT TRIG.

You can change trigger link line conﬁgurations by moving the position of resistors inside the unit. Perform the following steps to change trigger link lines:

WARNING Make sure the instrument is disconnected from the power line and other

equipment before performing the following procedure.

1. Remove the cover from the instrument as explained in Case cover removal.

2. The resistors used to select the trigger link lines are located next to the Trigger Link connector as shown in Figure 5-1. The “resistors” are actually solder beads that bridge PC-board pads. If the factory default lines are selected, the solder beads will be located at R270 (line 2, EXT TRIG) and R267 (line 1, VMC).

3. To change a trigger link line:

• Use a soldering iron and solder sucker to remove the appropriate solder bead.

• Using a solder with OA-based ﬂux, apply a solder bead to the appropriate resistor

• Replace the cover on the instrument.

Figure 5-1

Trigger link line connections

Trigger Link Lines Line 1 = VMC (R267)

Line 2 = EXT TRIG (R270) Line 3 = VMC (R266) Line 4 = EXT TRIG (R268) Line 5 = VMC (R265) Line 6 = EXT TRIG (R269)

location.

DMM Board

(View from top)

R270 R269 R268

Rear Panel

Solder Bead

Trigger

Link

Connector

(Factory Default Configured)

Main CPU ﬁrmware replacement

Changing the ﬁrmware may be necessary as upgrades become available. The ﬁrmware revision levels for the main and front panel CPUs are displayed during the po wer-on sequence. (The main ﬁrmware revision level is displayed on the left; the front panel ﬁrmware revision level is displayed on the right.) For example: REV: A01 A02 indicates a main ﬁrmware revision level of A01 and a front panel ﬁrmware revision level of A02.

The ﬁrmware for the main CPU is located in the EPROMs U156 (EVEN) and U157 (ODD), leadless ICs that resides in chip carriers on the PC board. To replace the CPU ﬁrmware, do the following:

WARNING Disconnect the instrument from the power lines, and remove the test leads

before changing the ﬁrmware.

Disassembly 5-11

1. Remove the case cover as described earlier in this section.

2. Locate U156 EVEN and U157 ODD (EPROMs) on the DMM (106) board. They are the only devices installed in chip carriers (sockets).

CAUTION EPROMs U156 and U157 are static-sensitive devices. Be sure to follow the

handling precautions explained in Static sensitive devices.

3. Using an appropriate chip extractor, remove U156 from its chip carrier.

4. Position the new U156 EPROM on the appropriate chip carrier. Make sure the notched corner of the chip is aligned with the notch in the chip carrier.

NOTE Be sure to install the correct EPROMs at the ODD and EVEN locations. The instru-

ment will not function if the EPROMs are installed in the wrong sockets.

5. With the EPROM properly positioned, push down on the chip until it completely seats into the chip carrier.

6. Repeat steps 3 through 5 for EPROM U157.

7. After installation, make sure the instrument powers up normally before replacing the cover.

5-12 Disassembly

Keithley 2015 Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual