Keithley 2400 Service Manual

Model 2400SourceMeter

®

Service Manual

A GREATER MEASURE OF CONFIDENCE

W ARRANTY

Keithley Instruments, Inc. warrants this product to be free from defects in material and workmanship for a
period of 1 year from date of shipment.

Keithley Instruments, Inc. warrants the following items for 90 days from the date of shipment: probes, cables,
rechargeable batteries, diskettes, and documentation.

During the warranty period, we will, at our option, either repair or replace any product that proves to be defec­tive.

To exercise this warranty, write or call your local Keithley representative, or contact Keithley headquarters in
Cleveland, Ohio. You will be given prompt assistance and return instructions. Send the product, transportation
prepaid, to the indicated service facility . Repairs will be made and the product returned, transportation prepaid.
Repaired or replaced products are warranted for the balance of the original warranty period, or at least 90 days.

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, non-recharge­able 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 T O ANY PERSON, OR DAMAGE T O PROPER TY.

Keithley Instruments, Inc. • 28775 Aurora Road • Cleveland, OH 44139 • 440-248-0400 • Fax: [phone] • http://www.k eithley.com

BELGIUM: Keithley Instruments B.V.
CHINA: Keithley Instruments China
FRANCE: Keithley Instruments Sarl 3, allée des Garays • 91127 Palaiseau Cedex • 01-64 53 20 20 • Fax: [phone]
GERMANY: Keithley Instruments GmbH Landsberger Strasse 65 • 82110 Germering • 089/84 93 07-40 • Fax: [phone]
GREAT BRITAIN: Keithley Instruments Ltd
INDIA: Keithley Instruments GmbH Flat 2B, WILOCRISSA • 14, Rest House Crescent • Bangalore 560 001 • 91-80-509-1320/21 • Fax: [phone]
ITALY: Keithley Instruments s.r.l. Viale S. Gimignano, 38 • 20146 Milano • 02-48 39 16 01 • Fax: [phone]
NETHERLANDS: Keithley Instruments B.V. Postbus 559 • 4200 AN Gorinchem • 0183-635333 • Fax: [phone]
SWITZERLAND: Keithley Instruments SA Kriesbachstrasse 4 • 8600 Dübendorf • 01-821 94 44 • Fax: [phone]
TAIWAN: Keithley Instruments Taiwan 1 Fl. 85 Po Ai Street • Hsinchu, Taiwan, R.O.C. • 886-3572-9077• Fax: [phone]

Bergensesteenweg 709 • B-1600 Sint-Pieters-Leeuw • 02/363 00 40 • Fax: [phone]
Y uan Chen Xin Building, Room 705 • 12 Y umin Road, De wai, Madian • Beijing 100029 • 8610-62022886 • Fax: [phone]

The Minster • 58 Portman Road • Reading, Berkshire RG30 1EA • 0118-9 57 56 66 • Fax: [phone]

9/00

Model 2400 SourceMeter

Service Manual

®

©1996, Keithley Instruments, Inc.

All rights reserved.

Cleveland, Ohio, U.S.A.

Fourth Printing, November 2000

Document Number: 2400-902-01 Rev. D

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 2400-902-01)............................................................January 1996

Revision B (Document Number 2400-902-01).......................................................... February 1996

Addendum B (Document Number 2400-902-02).................................................... September 1996

Revision C (Document Number 2400-902-01)..................................................................July 2000

Revision D (Document Number 2400-902-01)........................................................November 2000

All Keithley product names are trademarks or registered trademarks of Keithley Instruments, Inc.
Other brand names are trademarks or registered trademarks of their respective holders.

Safety Precautions

The following safety precautions should be observed before using this product and any associated in­strumentation. Although some instruments and accessories would normally be used with non-hazardous
voltages, there are situations where hazardous conditions may be present.

This product is intended for use by qualified personnel who recognize shock hazards and are familiar
with the safety precautions required to avoid possible injury. Read the operating information carefully
before using the product.

The types of product users are:

Responsible body is the individual or group responsible for the use and maintenance of equipment, for

ensuring that the equipment is operated within its specifications and operating limits, and for ensuring
that operators are adequately trained.

Operators use the product for its intended function. They must be trained in electrical safety procedures

and proper use of the instrument. They must be protected from electric shock and contact with hazardous
live circuits.

Maintenance personnel perform routine procedures on the product to keep it operating, for example,

setting the line voltage or replacing consumable materials. Maintenance procedures are described in the
manual. The procedures explicitly state if the operator may perform them. Otherwise, they should be
performed only by service personnel.

Service personnel are trained to work on live circuits, and perform safe installations and repairs of prod-

ucts. 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 con-

nector jacks or test fixtures. The American National Standards Institute (ANSI) states that a shock haz­ard exists when voltage lev els greater than 30V RMS, 42.4V peak, or 60VDC are present.

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,

As described in the International Electrotechnical Commission (IEC) Standard IEC 664, digital multi­meter measuring circuits (e.g., Keithley Models 175A, 199, 2000, 2001, 2002, and 2010) are Installation
Category II. All other instruments’ signal terminals are Installation Category I and must not be connect­ed to mains.

Do not connect switching cards directly to unlimited power circuits. They are intended to be used with
impedance limited sources. NEVER connect switching cards directly to AC mains. When connecting
sources to switching cards, install protective devices to limit fault current and voltage to the card.

Before operating an instrument, make sure the line cord is connected to a properly grounded power re­ceptacle. Inspect the connecting cables, test leads, and jumpers for possible wear, cracks, or breaks be­fore each use.

For maximum safety, do not touch the product, test cables, or any other instruments while power is ap­plied to the circuit under test. ALWAYS remove power from the entire test system and discharge any
capacitors before: connecting or disconnecting cables or jumpers, installing or removing switching
cards, or making internal changes, such as installing or removing jumpers.

no conductive part of the circuit may be exposed.

A good safety

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. Alw ays 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 scre w 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 av oid personal contact
with these voltages.

The

WARNING heading in a manual explains dangers that might result in personal injury or death. Always

read the associated information very carefully before performing the indicated procedure.
The

CAUTION heading in a manual explains hazards that could damage the instrument. Such damage may

invalidate the warranty.
Instrumentation and accessories shall not be connected to humans.
Before performing any maintenance, disconnect the line cord and all test cables.
To maintain protection from electric shock and fire, replacement components in mains circuits, including the

power transformer, test leads, and input jacks, must be purchased from Keithley Instruments. Standard fuses,
with applicable national safety approvals, may be used if the rating and type are the same. Other components
that are not safety related may be purchased from other suppliers as long as they are equivalent to the original
component. (Note that selected parts should be purchased only through Keithley Instruments to maintain ac­curacy and functionality of the product.) If you are unsure about the applicability of a replacement component,
call a Keithley Instruments office for information.

To clean an instrument, use a damp cloth or mild, water based cleaner. Clean the exterior of the instrument
only. Do not apply cleaner directly to the instrument or allow liquids to enter or spill on the instrument. Prod­ucts that consist of a circuit board with no case or chassis (e.g., data acquisition board for installation into a
computer) should never require cleaning if handled according to instructions. If the board becomes contami­nated and operation is affected, the board should be returned to the factory for proper cleaning/servicing.

Rev. 10/99

T able of Contents

1 Performance V erification

Introduction ................................................................................ 1-2

Verification test requirements ..................................................... 1-2

Environmental conditions ................................................... 1-2

Warm-up period .................................................................. 1-2

Line power .......................................................................... 1-3

Recommended test equipment ............................................ 1-3

Verification limits ................................................................ 1-3

Restoring factory defaults .......................................................... 1-4

Performing the verification test procedures ............................... 1-5

Test summary ...................................................................... 1-5

Test considerations .............................................................. 1-5

Setting the source range and output value .......................... 1-6

Setting the measurement range ........................................... 1-6

Compliance considerations ........................................................ 1-6

Compliance limits ............................................................... 1-6

Types of compliance ........................................................... 1-6

Maximum compliance values ............................................. 1-7

Determining compliance limit ............................................ 1-7

Taking the SourceMeter out of compliance ........................ 1-8

Output voltage accuracy ............................................................. 1-8

Voltage measurement accuracy ................................................ 1-10

Output current accuracy ........................................................... 1-11

Current measurement accuracy ................................................ 1-12

Resistance measurement accuracy ........................................... 1-13

2 Calibration

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

Environmental conditions .......................................................... 2-2

Temperature and relative humidity ..................................... 2-2

Warm-up period .................................................................. 2-2

Line power .......................................................................... 2-2

Calibration considerations .......................................................... 2-3

Calibration cycle ................................................................. 2-3

Recommended calibration equipment ................................. 2-4

Unlocking calibration .......................................................... 2-4

Changing the password ....................................................... 2-6

Resetting the calibration password ..................................... 2-6

Viewing calibration dates and calibration count ................. 2-7

Calibration errors ................................................................ 2-7

Front panel calibration ................................................................ 2-8

Remote calibration .................................................................... 2-16

Remote calibration commands .......................................... 2-16

Remote calibration procedure ........................................... 2-18

Single-range calibration ............................................................ 2-22

3 Routine Maintenance

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

Line fuse replacement ................................................................. 3-2

4 T roubleshooting

Introduction ................................................................................ 4-2

Repair considerations ................................................................. 4-2

Power-on self-test ....................................................................... 4-2

Front panel tests .......................................................................... 4-3

KEYS test ............................................................................ 4-3

DISPLAY PATTERNS test ................................................. 4-3

CHAR SET test ................................................................... 4-4

Principles of operation ................................................................ 4-4

Analog circuits .................................................................... 4-4

Power supply ....................................................................... 4-6

Output stage ......................................................................... 4-7

A/D converter ...................................................................... 4-8

Active guard ........................................................................ 4-8

Digital circuitry ................................................................... 4-8

Troubleshooting ........................................................................ 4-10

Display board checks ........................................................ 4-10

Power supply checks ......................................................... 4-10

Digital circuitry checks ..................................................... 4-11

Analog circuitry checks ..................................................... 4-11

Battery replacement .................................................................. 4-12

No comm link error .................................................................. 4-13

5 Disassembly

Introduction ................................................................................ 5-2

Handling and cleaning ................................................................ 5-2

Handling PC boards ............................................................ 5-2

Solder repairs ....................................................................... 5-2

Static sensitive devices ............................................................... 5-3

Assembly drawings ..................................................................... 5-3

Case cover removal ..................................................................... 5-4

Analog board removal ................................................................ 5-4

Digital board removal ................................................................. 5-6

Front panel disassembly ............................................................. 5-6

Removing power components .................................................... 5-7

Power supply removal ......................................................... 5-7

Power module removal ....................................................... 5-7

Instrument reassembly ............................................................... 5-7

6 Replaceable Parts

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

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

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

Factory service ........................................................................... 6-3

Component layouts .................................................................... 6-3

A Specifications

Accuracy calculations ............................................................. A-10

Measure accuracy ............................................................. A-10

Source accuracy ............................................................... A-10

B Command Reference

Introduction ............................................................................... B-2

Command summary .................................................................. B-2

Miscellaneous commands ......................................................... B-3

Detecting calibration errors ....................................................... B-9

Reading the error queue ..................................................... B-9

Error summary ................................................................... B-9

Status byte EAV (Error Available) bit .............................. B-10

Generating an SRQ on error ............................................ B-10

Detecting calibration step completion ..................................... B-11

Using the *OPC? query ................................................... B-11

Using the *OPC command ............................................... B-11

Generating an SRQ on calibration complete ................... B-12

C Calibration Programs

Introduction ............................................................................... C-2

Computer hardware requirements ............................................. C-2

Software requirements .............................................................. C-2

Calibration equipment ............................................................... C-2

General program instructions .................................................... C-3

Program C-1. Model 2400 calibration program ................ C-3

Requesting calibration constants ............................................... C-6

Program C-2. Requesting calibration constants ................ C-6

List of Illustrations

1 Performance V erification

Figure 1-1 Voltage verification front panel connections .......................... 1-9

Figure 1-2 Current verification connections .......................................... 1-11

Figure 1-3 Resistance verification connections ..................................... 1-15

2 Calibration

Figure 2-1 Voltage calibration connections ............................................. 2-9

Figure 2-2 Current calibration connections ........................................... 2-12

3 Routine Maintenance

Figure 3-1 Rear panel .............................................................................. 3-3

4 T roubleshooting

Figure 4-1 Analog circuit block diagram ................................................ 4-5

Figure 4-2 Power supply block diagram .................................................. 4-6

Figure 4-3 Output stage simplified schematic ......................................... 4-7

Figure 4-4 Digital board block diagram .................................................. 4-9

List of T ables

1 Performance V erification

Table 1-1 Recommended verification equipment .................................. 1-3

Table 1-2 Output voltage accuracy limits .............................................. 1-9

Table 1-3 Voltage measurement accuracy limits .................................. 1-10

Table 1-4 Output current accuracy limits ............................................. 1-12

Table 1-5 Current measurement accuracy limits .................................. 1-13

Table 1-6 Ohms measurement accuracy limits .................................... 1-14

2 Calibration

Table 2-1 Recommended calibration equipment ................................... 2-4

Table 2-2 Calibration unlocked states .................................................... 2-5

Table 2-3 Front panel voltage calibration ............................................ 2-11

Table 2-4 Front panel current calibration ............................................. 2-14

Table 2-5 Remote calibration command summary .............................. 2-16

Table 2-6 :CALibration:PROTected:SENSe parameter ranges ............ 2-17

Table 2-7 :CALibration:PROTected:SOURce parameter ranges ......... 2-17

Table 2-8 Voltage calibration initialization commands ........................ 2-18

Table 2-9 Voltage range calibration commands ................................... 2-19

Table 2-10 Current calibration initialization commands ........................ 2-20

Table 2-11 Current range calibration commands ................................... 2-21

3 Routine Maintenance

Table 3-1 Power line fuse ....................................................................... 3-2

4 T roubleshooting

Table 4-1 Display board checks ........................................................... 4-10

Table 4-2 Power supply checks ............................................................ 4-10

Table 4-3 Digital circuitry checks ........................................................ 4-11

Table 4-4 Analog circuitry checks ....................................................... 4-11

6 Replaceable Parts

Table 6-1 Analog board parts list ........................................................... 6-4

Table 6-2 Digital board parts list .......................................................... 6-10

Table 6-3 Display board parts list ........................................................ 6-13

Table 6-4 Mechanical parts list ............................................................ 6-14

B Command Reference

Table B-1 Remote calibration command summary ................................ B-2

Table B-2 :CALibration:PROTected:SENSe parameter ranges ............. B-6

Table B-3 :CALibration:PROTected:SOURce parameter ranges .......... B-8

Table B-4 Calibration errors ................................................................ B-10

1

Performance V erification

1-2 Performance Verification

Introduction

Use the procedures in this section to verify that Model 2400 accuracy is within the limits stated
in the instrument’s one-year accuracy specifications. You can perform these verification
procedures:

• When you first receive the instrument to make sure that it was not damaged during
shipment.

• To verify that the unit meets factory specifications.

• To determine if calibration is required.

• Following calibration to make sure it was performed properly.

WARNING The information in this section is intended for qualified service personnel

only. Do not attempt these procedures unless you are qualified to do so.
Some of these procedures may expose you to hazardous voltages, which
could cause personal injury or death if contacted. Use standard safety pre­cautions when working with hazardous voltages.

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.

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 test equipment.

• Using the specified output signal and reading limits.

Environmental conditions

Conduct your performance verification procedures in a test environment with:

• An ambient temperature of 18-28°C (65-82°F).

• A relative humidity of less than 70% unless otherwise noted.

W arm-up period

Allow the Model 2400 to warm up for at least one hour before conducting the verification
procedures. If the instrument has been subjected to temperature extremes (those outside the
ranges stated above), allow additional time for the instrument’s internal temperature to
stabilize. Typically, allow one extra hour to stabilize a unit that is 10°C (18°F) outside the
specified temperature range.

Also, allow the test equipment to warm up for the minimum time specified by the
manufacturer.

Performance Verification 1-3

Line power

The Model 2400 requires a line voltage of 88 to 264V and a line frequency of 50 or 60Hz.
Verification tests should be performed within this range.

Recommended test equipment

Table 1-1 summarizes recommended verification equipment. You can use alternate equipment
as long as that equipment has specifications at least as good as those listed in Table 1-1. Keep
in mind, however, that test equipment uncertainty will add to the uncertainty of each measure­ment. Generally, test equipment uncertainty should be at least four times better than corre­sponding Model 2400 specifications. Table 1-1 lists the uncertainties of the recommended test
equipment.

Table 1-1

Recommended verifi cation equipment

Description Manufacturer/Model Accuracy*

Digital Multimeter

Resistance calibrator

**90-day specifications show accuracy at specified measurement point.

**Nominal resistance values shown.

Hewlett Packard
HP3458A

Fluke 5450A

DC Voltage

DC current

Resistance**

200mV:
2V:
20V:
200V:
1µA:
10µA:
100µA:
1mA:
10mA:
100mA:
1A:
19

Ω :

190

Ω :

1.9k

Ω :

19k

Ω

190k Ω :

1.9M

Ω :

19M

Ω :

100M

Ω :

±15ppm
±6ppm
±9ppm
±7ppm
±55ppm
±25ppm
±23ppm
±20ppm
±20ppm
±35ppm
±110ppm
±23ppm
±10.5ppm
±8ppm
±7.5ppm
±8.5ppm
±11.5ppm
±30ppm
±120ppm

V erification limits

The verification limits stated in this section have been calculated using only the Model 2400
one-year accuracy specifications, and they do not include test equipment uncertainty. If a
particular measurement falls outside the allowable range, recalculate new limits based both on
Model 2400 specifications and corresponding test equipment specifications.

1-4 Performance Verification

Example limits calculation

As an example of how verification limits are calculated, assume you are testing the 20V DC
output range using a 20V output value. Using the Model 2400 one-year accuracy specification
for 20V DC output of ±(0.02% of output + 2.4mV offset), the calculated output limits are:

Output limits = 20V ± [(20V
Output limits = 20V ± (0.004 + 0.0024)
Output limits = 20V ± 0.0064V
Output limits = 19.9936V to 20.0064V

× 0.02%) + 2.4mV]

Resistance limits calculation

When verifying the ohms function, you may find it necessary to recalculate resistance limits
based on the actual calibrator resistance values. You can calculate resistance reading limits in
the same manner described above, but be sure to use the actual calibrator resistance values and
the Model 2400 normal accuracy specifications for your calculations.

As an example, assume that you are testing the 20k
19k

Ω calibrator resistor is 19.025k Ω . Using the Model 2400 one-year normal accuracy

specifications of ±(0.063% of reading + 3
Reading limits = 19.025k

Reading limits = 19.025k
Reading limits = 19.0100k Ω to 19.0400k Ω

Ω ±[(19.025k Ω × 0.063%) + 3 Ω ]
Ω ± 15 Ω

Restoring factory defaults

Before performing the verification procedures, restore the instrument to its factory front panel
(bench) defaults as follows:

1. Press MENU key. The instrument will display the following prompt:

MAIN MENU

SAVESETUP COMMUNICATION CAL

2. Select SAVESETUP, and then press ENTER. The unit then displays:

SETUP MENU

SAVE RESTORE POWERON RESET

3. Select RESET, and then press ENTER. The unit displays:

RESET ORIGINAL DFLTS

BENCH GPIB

4. Select BENCH, and then press ENTER. The unit then displays:

RESETTING INSTRUMENT

ENTER to confirm; EXIT to abort

5. Press ENTER to restore bench defaults, and note the unit displays the following:

RESET COMPLETE

BENCH defaults are now restored



Press ENTER to continue

6. Press ENTER and then EXIT to return to normal display.

Ω range, and the actual value of the nominal

Ω ), the recalculated reading limits are:





Performance Verification 1-5

Performing the verification test procedures

T est summary

• DC voltage output accuracy

• DC voltage measurement accuracy

• DC current output accuracy

• DC current measurement accuracy

• Resistance measurement accuracy

If the Model 2400 is not within specifications and not under warranty, see the calibration
procedures in Section 2 for information on calibrating the unit.

T est considerations

When performing the verification procedures:

• Be sure to restore factory front panel defaults as outlined above.

• Make sure that the test equipment is properly warmed up and connected to the
Model 2400 INPUT/OUTPUT jacks. Also ensure that the front panel jacks are selected
with the TERMINALS key.

• Make sure the Model 2400 is set to the correct source range.

• Be sure the Model 2400 output is turned on before making measurements.

• Be sure the test equipment is set up for the proper function and range.

• Allow the Model 2400 output signal to settle before making a measurement.

• Do not connect test equipment to the Model 2400 through a scanner, multiplexer, or
other switching equipment.

WARNING The maximum common-mode voltage (voltage between LO and chassis

ground) is 250V peak. Exceeding this value may cause a breakdown in
insulation, creating a shock hazard.

CAUTION The maximum voltage between INPUT/OUTPUT HI and LO or 4-WIRE

SENSE HI and LO is 250V peak. The maximum voltage between INPUT/
OUTPUT HI and 4-WIRE SENSE HI or between INPUT/OUTPUT LO
and 4-WIRE SENSE LO is 5V. Exceeding these voltages may result in
instrument damage.

1-6 Performance Verification

Setting the source range and output value

Before testing each verification point, you must properly set the source range and output value
as outlined below.

1. Press either the SOURCE V or SOURCE I key to select the appropriate source
function.

2. Press the EDIT key as required to select the source display field. Note that the cursor
will flash in the source field while its value is being edited.

3. With the cursor in the source display field flashing, set the source range to the lowest
possible range for the value to be sourced using the up or do wn RANGE k ey. For exam­ple, you should use the 20V source range to output a 19V or 20V source value. With a
20V source value and the 20V range selected, the source field display will appear as
follows:

Vsrc:+20.0000 V

4. With the source field cursor flashing, set the source output to the required value using
either:

• The SOURCE adjustment and left and right arrow keys.

• The numeric keys.

5. Note that the source output value will be updated immediately; you need not press
ENTER when setting the source value.

Setting the measurement range

When simultaneously sourcing and measuring either voltage or current, the measure range is
coupled to the source range, and you cannot independently control the measure range. Thus, it
is not necessary for you to set the range when testing voltage or current measurement accurac y.

Compliance considerations

Compliance limits

When sourcing voltage, you can set the SourceMeter to limit current from 1nA to 1.05A.
Conversely, when sourcing current, you can set the SourceMeter to limit voltage from 200µV
to 210V. The SourceMeter output will not exceed the programmed compliance limit.

T ypes of compliance

There are two types of compliance that can occur: “real” and “range.” Depending upon which
value is lower , the output will clamp at either the displayed compliance setting (“real”) or at the
maximum measurement range reading (“range”).

The “real” compliance condition can occur when the compliance setting is less than the highest
possible reading of the measurement range. When in compliance, the source output clamps at
the displayed compliance value. For example, if the compliance voltage is set to 1V and the
measurement range is 2V, the output voltage will clamp (limit) at 1V.

“Range” compliance can occur when the compliance setting is higher than the possible reading
of the selected measurement range. When in compliance, the source output clamps at the
maximum measurement range reading (not the compliance value). For example, if the
compliance voltage is set to 1V and the measurement range is 200mV, the output voltage will
clamp (limit) at 210mV.

Maximum compliance values

The maximum compliance values for the measurement ranges are summarized as follows:

Performance Verification 1-7

Measurement

range

200mV

2V

20V

200V

1µA

10µA

100µA

1mA

10mA

100mA

1A

When the SourceMeter goes into compliance, the “Cmpl” label or the units label (i.e., “mA”)
for the compliance display will flash.

Maximum

compliance value

210mV

1.05µA

10.5µA

1.05mA

10.5mA
105mA

Determining compliance limit

The relationships to determine which compliance is in effect are summarized as follows. They
assume the measurement function is the same as the compliance function.

• Compliance Setting < Measurement Range = Real Compliance

• Measurement Range < Compliance Setting = Range Compliance

2.1V
21V

210V

105µA

1.05A

You can determine the compliance that is in effect by comparing the displayed compliance
setting to the present measurement range. If the compliance setting is lower than the maximum
possible reading on the present measurement range, the compliance setting is the compliance
limit. If the compliance setting is higher than the measurement range, the maximum reading on
that measurement range is the compliance limit.

1-8 Performance Verification

T aking the SourceMeter out of compliance

Verification measurements should not be made when the SourceMeter is in compliance. For
purposes of the verification tests, the SourceMeter can be taken out of compliance by going
into the edit mode and increasing the compliance limit.

NOTE Do not take the unit out of compliance by decreasing the source value or changing

the range. Always use the recommended range and source settings when performing
the verification tests.

Output voltage accuracy

Follow the steps below to verify that Model 2400 output voltage accuracy is within specified
limits. This test involves setting the output voltage to each full-range value and measuring the
voltages with a precision digital multimeter.

1. With the power of f, connect the digital multimeter to the Model 2400 INPUT/OUTPUT
jacks, as shown in Figure 1-1.

2. Select the multimeter DC volts measuring function.

NOTE The default voltage source protection value is 40V . Befor e testing the 200V r ange, set

the voltage source protection value to >200V. To do so, press CONFIG then
SOURCE V to access the CONFIGURE V-SOURCE menu, then select PROTEC­TION and set the limit value to >200V.

3. Press the Model 2400 SOURCE V k ey to source voltage, and make sure the source out­put is turned on.

4. Verify output voltage accuracy for each of the voltages listed in Table 1-2. For each test
point:

• Select the correct source range.

• Set the Model 2400 output voltage to the indicated value.

• Verify that the multimeter reading is within the limits given in the table.

Fi

gure 1-

1

Voltage verifi cation front panel connections

EDIT

DISPLAY

TOGGLE

POWER

V

LOCAL

67

DIGITS SPEED

MEAS

FCTN

I

Ω

1

230

REL

FILTER

LIMIT

89

STORE

RECALL

V

4

TRIG

SWEEP

+/-

CONFIG MENU

I

5

SOURCE

Model 2400

EDIT

EXIT ENTER

2400 SourceMeter

RANGE

AUTO

RANGE

Performance Verification 1-9

4-WIRE

INPUT/

SENSE

OUTPUT

HI

250V
PEAK

ON/OFF

OUTPUT

250V

5V

PEAK

PEAK

LO

250V
PEAK

TERMINALS

FRONT/

REAR

Input HI

Input LO

Digital Multimeter

5. Repeat the procedure for negative output voltages with the same magnitudes as those
listed in Table 1-2.

6. Repeat the entire procedure using the rear panel INPUT/OUTPUT jacks. Be sure to
select the rear panel jacks with the front panel TERMINALS key.

Table 1-2

Output voltage accuracy limits

Model 2400

source range

200mV

2V

20V

200V

Model 2400

output voltage setting

200.000mV

2.00000V

20.0000V

200.000V

Output voltage limits

(1 year, 18°C–28°C)

199.360 to 200.640mV

1.99900 to 2.00100V

19.9936 to 20.0064V

199.936 to 200.064V

1-10 Performance Verification

V oltage measurement accuracy

Follow the steps below to verify that Model 2400 voltage measurement accuracy is within
specified limits. The test involves setting the source voltage to 95% of full-range values, as
measured by a precision digital multimeter, and then verifying that the Model 2400 voltage
readings are within required limits.

1. With the power of f, connect the digital multimeter to the Model 2400 INPUT/OUTPUT
jacks, as shown in Figure 1-1.

2. Select the multimeter DC volts function.

NOTE The default voltage source protection value is 40V . Befor e testing the 200V r ange, set

the voltage source protection value to >200V. To do so, press CONFIG then
SOURCE V to access the CONFIGURE V-SOURCE menu, then select PROTEC­TION and set the limit value to >200V.

3. Set the Model 2400 to both source and measure voltage by pressing the SOURCE V
and MEAS V keys, and make sure the source output is turned on.

4. Verify output voltage accuracy for each of the voltages listed in Table 1-3. For each test
point:

• Select the correct source range.

• Set the Model 2400 output voltage to the indicated value as measured by the digital
multimeter.

• Verify that the Model 2400 voltage reading is within the limits given in the table.

NOTE It may not be possible to set the voltage sour ce to the specified value . Use the closest

possible setting, and modify reading limits accordingly.

5. Repeat the procedure for negative source voltages with the same magnitudes as those
listed in Table 1-3.

6. Repeat the entire procedure using the rear panel INPUT/OUTPUT jacks. Be sure to
select the rear panel jacks with the front panel TERMINALS key.

Table 1-3

Voltage measurement accuracy limits

Model 2400 source and

measure range* Source voltage**

0200mv 190.000mV 189.677 to 190.323mV

002V 1.90000V 1.89947 to 1.90053V
020V 19.0000V 18.9962 to 19.0038V

200V 190.000V 189.962 to 190.038V

**Measure range coupled to source range when simultaneously sourcing and measuring voltage.

**As measured by precision digital multimeter. Use closest possible value, and modify reading limits

accordingly if necessary.

Model 2400 voltage reading limits

(1 year, 18°C–28°C)

Output current accuracy

Fi

2

Follow the steps below to verify that Model 2400 output current accuracy is within specified
limits. The test involves setting the output current to each full-range value and measuring the
currents with a precision digital multimeter.

1. With the power of f, connect the digital multimeter to the Model 2400 INPUT/OUTPUT
jacks, as shown in Figure 1-2.

2. Select the multimeter DC current measuring function.

3. Press the Model 2400 SOURCE I key to source current, and make sure the source out­put is turned on.

gure 1-

Current verifi cation connections

Performance Verification 1-11

4-WIRE

INPUT/

SENSE

OUTPUT

HI

EDIT

DISPLAY

TOGGLE

POWER

V

REL

LOCAL

67

DIGITS SPEED

250V
PEAK

MEAS

FCTN

I

Ω

230

LIMIT

89

RECALL

V

4

TRIG

SWEEP

+/-

CONFIG MENU

5

1

FILTER

STORE

SOURCE

I

EDIT

EXIT ENTER

2400 SourceMeter

RANGE

AUTO

RANGE

OUTPUT

ON/OFF

250V

5V

PEAK

PEAK

LO

250V
PEAK

TERMINALS

FRONT/

REAR

Model 2400

Input LO

Amps

Digital Multimeter

1-12 Performance Verification

4. Verify output current accuracy for each of the currents listed in Table 1-4. For each test
point:

• Select the correct source range.

• Set the Model 2400 output current to the correct value.

• Verify that the multimeter reading is within the limits given in the table.

5. Repeat the procedure for negative output currents with the same magnitudes as those
listed in Table 1-4.

6. Repeat the entire procedure using the rear panel INPUT/OUTPUT jacks. Be sure to
select the rear panel jacks with the front panel TERMINALS key.

Table 1-4

Output current accuracy limits

Model 2400

source range

1µA

10µA

100µA

1mA

10mA

100mA

1A

Model 2400 output

current setting

1.00000µA

10.0000µA

100.000µA

1.00000mA

10.0000mA

100.000mA

1.00000A

Current measurement accuracy

Follow the steps below to verify that Model 2400 current measurement accuracy is within
specified limits. The procedure involves applying accurate currents from the Model 2400
current source and then verifying that Model 2400 current measurements are within required
limits.

1. With the power of f, connect the digital multimeter to the Model 2400 INPUT/OUTPUT
jacks as shown in Figure 1-2.

2. Select the multimeter DC current function.

3. Set the Model 2400 to both source and measure current by pressing the SOURCE I and
MEAS I keys, and make sure the source output is turned on.

4. Verify measure current accuracy for each of the currents listed in Table 1-5. For each
measurement:

• Select the correct source range.

• Set the Model 2400 source output to the correct value as measured by the digital
multimeter.

• Verify that the Model 2400 current reading is within the limits given in the table.

Output current limits

(1 year, 18°C–28°C)

0.99905 to 1.00095µA

9.9947 to 10.0053µA

99.949 to 100.051µA

0.99946 to 1.00054mA

9.9935 to 10.0065mA

99.914 to 100.086mA

0.99640 to 1.00360A

Performance Verification 1-13

NOTE It may not be possible to set the current source to the specified value. Use the closest

possible setting, and modify reading limits accordingly.

5. Repeat the procedure for negativ e calibrator currents with the same magnitudes as those

listed in Table 1-5.

6. Repeat the entire procedure using the rear panel INPUT/OUTPUT jacks. Be sure to

select the rear panel jacks with the front panel TERMINALS key.

Table 1-5

Current measurement accuracy limits

Model 2400 source and

measure range* Source current**

1µA

10µA

100µA

1mA

10mA

100mA

1A

**Measure range coupled to source range when simultaneously sourcing and measuring current.

**As measured by precision digital multimeter. Use closest possible value, and modify reading limits

accordingly if necessary.

0.95000µA

9.5000µA

95.000µA

0.95000mA

9.5000mA

95.000mA

0.95000A

Resistance measurement accuracy

Follow the steps below to verify that Model 2400 resistance measurement accuracy is within
specified limits. This procedure involves applying accurate resistances from a resistance
calibrator and then verifying that Model 2400 resistance measurements are within required
limits.

1. With the power off, connect the resistance calibrator to the Model 2400 INPUT/OUT-

PUT and 4-WIRE SENSE jacks as shown in Figure 1-3. Be sure to use the four-wire
connections as shown

2. Select the resistance calibrator external sense mode.

3. Configure the Model 2400 ohms function for the 4-wire sense mode as follows:

• Press CONFIG then MEAS

CONFIG OHMS

SOURCE SENSE-MODE GUARD

• Select SENSE-MODE, and then press ENTER. The following will be displayed:

SENSE-MODE

2-WIRE 4-WIRE

• Select 4-WIRE, and then press ENTER.

• Press EXIT to return to normal display.

Ω . The instrument will display the following:

Model 2400 current reading limits

(1 year, 18°C–28°C)

0.94942 to 0.95058µA

9.4967 to 9.5033µA

94.970 to 95.030µA

0.94968 to 0.95032mA

9.4961 to 9.5039mA

94.942 to 95.058mA

0.94734 to 0.95266A

1-14 Performance Verification

4. Press MEAS Ω to select the ohms measurement function, and make sure the source out­put is turned on.

5. Verify ohms measurement accuracy for each of the resistance values listed in T able 1-6.
For each measurement:

• Set the resistance calibrator output to the nominal resistance or closest available
value.

NOTE It may not be possible to set the resistance calibrator to the specified value. Use the

closest possible setting, and modify reading limits accordingly.

• Select the appropriate ohms measurement range with the RANGE keys.

• Verify that the Model 2400 resistance reading is within the limits given in the
table.

6. Repeat the entire procedure using the rear panel INPUT/OUTPUT and 4-WIRE
SENSE jacks. Be sure to select the rear panel jacks with the front panel TERMINALS
key.

Table 1-6

Ohms measurement accuracy limits

Calibrator

Model 2400 range

20Ω

200Ω

2kΩ

20kΩ

200kΩ

2MΩ

20MΩ

200MΩ

** Nominal resistance value.

** Reading limits based on Model 2400 normal accuracy specifications and nominal resistance values. If

actual resistance values differ from nominal values shown, recalculate reading limits using actual calibrator
resistance values and Model 2400 normal accuracy specifications. See “Verification limits” earlier in this
section for details.

resistance*

19Ω

190Ω

1.9kΩ
19kΩ

190kΩ

1.9MΩ
19MΩ

100MΩ

Model 2400 resistance reading limits**

(1 year, 18°C-28°C)

18.9784 to 19.0216Ω

189.824 to 190.176Ω

1.89845 to 1.90155kΩ

18.9850 to 19.0150kΩ

189.847 to 190.153kΩ

1.89761 to 1.90239MΩ

18.9781 to 19.0219MΩ

99.020 to 100.980MΩ

Fi

gure 1-

3

Resistance verifi cation connections

V

LOCAL

67

DIGITS SPEED

MEAS

I

Ω

1

REL

FILTER

STORE

EDIT

DISPLAY

TOGGLE

POWER

FCTN

230

LIMIT

89

RECALL

CONFIG MENU

Model 2400

Performance Verification 1-15

4-WIRE

INPUT/

SENSE

OUTPUT

HI

250V
PEAK

2400 SourceMeter

SOURCE

I

V

4

5

TRIG

SWEEP

+/-

EXIT ENTER

RANGE

EDIT

AUTO

ON/OFF

RANGE

OUTPUT

250V

5V

PEAK

PEAK

LO

250V

PEAK

TERMINALS

FRONT/

REAR

Output HI

Sense HI

Resistance Calibrator

Output LO

Sense LO

1-16 Performance Verification