Fluke 525B Operating Manual

525B

Temperature/Pressure Calibrator

July 2012

© 2012 Fluke Corporation, All rights reserved.
All product names are trademarks of their respective companies.

Users Manual

LIMITED WARRANTY AND LIMITATION OF LIABILITY

Each Fluke product is warranted to be free from defects in material and workmanship under normal
use and service. The warranty period is one year and begins on the date of shipment. Parts, product
repairs, and services are warranted for 90 days. This warranty extends only to the original buyer or
end-user customer of a Fluke authorized reseller, and does not apply to fuses, disposable batteries,
or to any product which, in Fluke's opinion, has been misused, altered, neglected, contaminated, or
damaged by accident or abnormal conditions of operation or handling. Fluke warrants that software
will operate substantially in accordance with its functional specifications for 90 days and that it has
been properly recorded on non-defective media. Fluke does not warrant that software will be error
free or operate without interruption.

Fluke authorized resellers shall extend this warranty on new and unused products to end-user
customers only but have no authority to extend a greater or different warranty on behalf of Fluke.
Warranty support is available only if product is purchased through a Fluke authorized sales outlet or
Buyer has paid the applicable international price. Fluke reserves the right to invoice Buyer for
importation costs of repair/replacement parts when product purchased in one country is submitted for
repair in another country.

Fluke's warranty obligation is limited, at Fluke's option, to refund of the purchase price, free of charge
repair, or replacement of a defective product which is returned to a Fluke authorized service center
within the warranty period.

To obtain warranty service, contact your nearest Fluke authorized service center to obtain return
authorization information, then send the product to that service center, with a description of the
difficulty, postage and insurance prepaid (FOB Destination). Fluke assumes no risk for damage in
transit. Following warranty repair, the product will be returned to Buyer, transportation prepaid (FOB
Destination). If Fluke determines that failure was caused by neglect, misuse, contamination,
alteration, accident, or abnormal condition of operation or handling, including overvoltage failures
caused by use outside the product’s specified rating, or normal wear and tear of mechanical
components, Fluke will provide an estimate of repair costs and obtain authorization before
commencing the work. Following repair, the product will be returned to the Buyer transportation
prepaid and the Buyer will be billed for the repair and return transportation charges (FOB Shipping
Point).

THIS WARRANTY IS BUYER'S SOLE AND EXCLUSIVE REMEDY AND IS IN LIEU OF ALL
OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY
IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
FLUKE SHALL NOT BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL, OR
CONSEQUENTIAL DAMAGES OR LOSSES, INCLUDING LOSS OF DATA, ARISING FROM ANY
CAUSE OR THEORY.

Since some countries or states do not allow limitation of the term of an implied warranty, or exclusion
or limitation of incidental or consequential damages, the limitations and exclusions of this warranty
may not apply to every buyer. If any provision of this Warranty is held invalid or unenforceable by a
court or other decision-maker of competent jurisdiction, such holding will not affect the validity or
enforceability of any other provision.

Fluke Corporation
P.O. Box 9090
Everett, WA 98206-9090
U.S.A.

Fluke Europe B.V.
P.O. Box 1186
5602 BD Eindhoven
The Netherlands

11/99

To register your product online, visit register.fluke.com

Table of Contents

Chapter Title Page

1 Getting Started ................................................................................... 1-1

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

Contacting Fluke .............................................................................................. 1-1

Standard Equipment ......................................................................................... 1-2

Options and Accessories .................................................................................. 1-2

Safety Information ........................................................................................... 1-2

Getting Acquainted with the Calibrator ........................................................... 1-5

Input and Output Terminals ...................................................................... 1-5

Using the Keys .......................................................................................... 1-6

Display Error Messages ............................................................................ 1-10

Rear Panel View ........................................................................................ 1-11

2 Using Output Mode ........................................................................... 2-1

Using Output Mode ......................................................................................... 2-1

Simulating Thermocouple Temperature .................................................... 2-2

Simulating Temperature Using Resistance Temperature

Detectors (RTDs) ...................................................................................... 2-3

Simulating Custom RTD Coefficients ...................................................... 2-4

Default RTD Coefficients ......................................................................... 2-5

Entering Custom Standard Platinum Resistance Thermometer (SPRT)

Coefficients ............................................................................................... 2-6

Output DC Voltage.................................................................................... 2-7

Output Resistance ...................................................................................... 2-8

Output Current ................................................................................................. 2-9

3 Using Input Mode .............................................................................. 3-1

Using Input Mode ............................................................................................ 3-1

Measuring Resistance ................................................................................ 3-1

Measuring Temperature Using Thermocouples ........................................ 3-2

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Users Manual

Thermocouple Zero Calibration ........................................................... 3-4

Measuring Temperature Using Resistance Temperature

Detectors (RTDs) ...................................................................................... 3-5

Entering and Using Custom RTDs ........................................................... 3-7

Default RTD Coefficients ......................................................................... 3-8

Entering Custom SPRT Coefficients ........................................................ 3-9

Measuring Pressure ................................................................................... 3-10

4 Remote Operation ............................................................................. 4-1

Introduction ..................................................................................................... 4-1

Setting up the RS-232 Port for Remote Control .............................................. 4-2

RS-232 Port Setup Procedure ................................................................... 4-2

Testing the RS-232 Port ....................................................................... 4-2

RS-232 Interface Overview ............................................................................. 4-5

Setting up the IEEE-488 Port for Remote Control .......................................... 4-5

IEEE-488 Port Setup Procedure ............................................................... 4-7

Testing the IEEE-488 Port ........................................................................ 4-7

Changing Between Remote and Local Operation ........................................... 4-8

Local State ................................................................................................ 4-8

Local with Lockout State .......................................................................... 4-8

Remote State ............................................................................................. 4-8

Remote with Lockout State ....................................................................... 4-9

IEEE-488 Interface Overview ......................................................................... 4-10

Using Commands ............................................................................................ 4-13

Types of Commands ................................................................................. 4-13

Device-Dependent Commands ............................................................. 4-13

Common Commands ............................................................................ 4-13

Query Commands ................................................................................. 4-14

Interface Messages (IEEE-488) ............................................................ 4-14

Compound Commands ......................................................................... 4-16

Overlapped Commands ........................................................................ 4-16

Sequential Commands .......................................................................... 4-17

Commands for RS-232 Only ................................................................ 4-17

Commands for IEEE-488 Only ............................................................ 4-17

Command Syntax ...................................................................................... 4-18

Parameter Syntax Rules ........................................................................ 4-18

Extra Space or Tab Characters ............................................................. 4-19

Terminators .......................................................................................... 4-19

Incoming Character Processing ............................................................ 4-20

Response Message Syntax .................................................................... 4-20

Checking 525B Status ..................................................................................... 4-21

Serial Poll Status Byte (STB) ................................................................... 4-23

Service Request (SRQ) Line ................................................................ 4-23

Service Request Enable Register (SRE) ............................................... 4-24

ii

Contents (continued)

Programming the STB and SRE ........................................................... 4-24

Event Status Register (ESR) ................................................................. 4-24

Event Status Enable (ESE) Register ..................................................... 4-24

Bit Assignments for the ESR and ESE ................................................. 4-25

Programming the ESR and ESE ........................................................... 4-26

Output Queue ............................................................................................ 4-26

Error Queue ............................................................................................... 4-26

Input Buffer Operation .............................................................................. 4-26

5 Remote Commands ........................................................................... 5-1

Introduction ...................................................................................................... 5-1

Command Summary by Function .................................................................... 5-1

Common Commands ................................................................................. 5-1

External Connection Commands ............................................................... 5-2

Output Commands .................................................................................... 5-3

Measurement Commands .......................................................................... 5-3

RS-232 Port Commands ............................................................................ 5-3

Status Commands ...................................................................................... 5-4

Error Code Listing ........................................................................................... 5-4

Remote Command Listing ............................................................................... 5-5

6 Maintaining the Calibrator ................................................................ 6-1

Maintenance ..................................................................................................... 6-1

Cleaning the Calibrator ............................................................................. 6-1

Replacing a Line Fuse ............................................................................... 6-1

Changing Line Voltage ............................................................................. 6-2

Performance Tests ........................................................................................... 6-4

Required Equipment List .......................................................................... 6-4

Testing DC Voltage ................................................................................... 6-5

Testing DC Current ................................................................................... 6-6

Testing Thermocouple Output .................................................................. 6-7

Testing CJC (Cold Junction Compensation) ......................................... 6-8

Testing Thermocouple Input ................................................................. 6-9

Testing Ohms Output ................................................................................ 6-10

Testing Ohms Input ................................................................................... 6-11

Testing Pressure Modules ......................................................................... 6-13

Service Center Calibration or Repair ............................................................... 6-14

Replacement Parts ........................................................................................... 6-15

Accessories ...................................................................................................... 6-17

7 Specifications .................................................................................... 7-1

General Specifications ..................................................................................... 7-1

Electrical Specifications .................................................................................. 7-2

DC Voltage Specifications, Output ........................................................... 7-2

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Users Manual

DC Current Specifications, Output ........................................................... 7-2

Resistance Specifications, Output ............................................................. 7-3

Resistance Specifications, Input ............................................................... 7-3

Thermocouple Specification, Output and Input ........................................ 7-4

RTD and Thermistor Specification, Output .............................................. 7-5

RTD and Thermistor Specification, Input ................................................ 7-6

Pressure Measurement ..................................................................................... 7-8

iv

List of Tables

Table Title Page

1-1. Summary of Input and Output Functions......................................................... 1-2

1-2. Symbols Used on the Calibrator ...................................................................... 1-4

1-3. Pushbutton Usage Functions ............................................................................ 1-7

1-4. Function Keys .................................................................................................. 1-8

1-5. Display Error Messages ................................................................................... 1-10

2-1. Default RTD Coefficients ................................................................................ 2-5

2-2. Other Commonly Used RTDs .......................................................................... 2-5

3-1. Default RTD Coefficients ................................................................................ 3-8

3-2. Other Commonly Used RTDs .......................................................................... 3-8

4-1. RS-232 Interface Wiring .................................................................................. 4-5

4-2. Operating State Transitions ............................................................................. 4-9

4-3. RS-232 Emulation of IEEE-488 Messages ...................................................... 4-10

4-4. IEEE-488 Remote Message Coding ................................................................ 4-11

4-5. IEEE-488 Interface Messages (Received) ....................................................... 4-15

4-6. IEEE-488 Interface Messages (Sent) ............................................................... 4-16

4-7. Commands for RS-232 Only ........................................................................... 4-17

4-8. Units Accepted in Parameters and Used in Responses .................................... 4-18

4-9. Terminator Characters ..................................................................................... 4-19

4-10. Response Data Types ....................................................................................... 4-21

4-11. Status Register Summary ................................................................................. 4-21

6-1. Replacement Fuses .......................................................................................... 6-2

6-2. Required Equipment ........................................................................................ 6-4

6-3. Measuring DC Voltage .................................................................................... 6-5

6-4. Measuring DC Current..................................................................................... 6-6

6-5. TC Temperatures ............................................................................................. 6-7

6-6. Ohms Output Ranges ....................................................................................... 6-10

6-6. Ohms Ratio Table ............................................................................................ 6-12

6-8. Replacement Parts ........................................................................................... 6-16

6-9. Fluke 700 SeriesPressure Modules .................................................................. 6-17

6-10. Fluke 525A-P Series Pressure Modules ........................................................... 6-18

v

525B

Users Manual

vi

List of Figures

Figure Title Page

1-1. Input and Output Terminals and Connectors ................................................... 1-5

1-2. Pushbuttons ...................................................................................................... 1-6

1-3. Calibrator Function Keys ................................................................................. 1-8

1-4. Rear Panel View .............................................................................................. 1-11

2-1. Connection to Simulate Thermocouple Temperature ...................................... 2-2

2-2. Connection to Simulate a RTD Temperature ................................................... 2-3

2-3. Connection for Setting DC Voltage Output ..................................................... 2-7

2-4. Connection for Setting Resistance Output ....................................................... 2-8

2-5. Connection for Setting Current Output ............................................................ 2-9

3-1. Measuring Resistance Using a 4-Wire to 2-Wire Connection ......................... 3-2

3-2. Measuring Temperature with a Thermocouple ................................................ 3-3

3-3. Measuring RTD Output from an Instrument ................................................... 3-5

3-4. Measuring Temperature using an RTD Probe ................................................. 3-6

3-5. Connection for Measuring Pressure ................................................................. 3-10

4-1. Testing the RS-232 Port ................................................................................... 4-2

4-2. Typical RS-232 Remote Control Connections ................................................ 4-4

4-3. Typical IEEE-488 Remote Control Connections ............................................. 4-6

4-4. Testing the IEEE-488 Port ............................................................................... 4-7

4-5. Status Register Overview................................................................................. 4-22

4-6. Serial Poll Status Byte (STB) and Service Request Enable (SRE) .................. 4-23

6-1. Accessing the Fuse .......................................................................................... 6-3

6-2. Measuring DC Current..................................................................................... 6-6

6-3. Testing TC Output ........................................................................................... 6-7

6-4. Connections for CJC Calibration ..................................................................... 6-8

6-5. Connections for Measuring TC Input .............................................................. 6-9

6-6. Connection for Measuring Resistance Output ................................................. 6-10

6-7. 8508A/01 Connection Diagram ....................................................................... 6-11

6-8. Connection for Measuring Ohms ..................................................................... 6-13

6-9. Exploded View of the 525B ............................................................................. 6-15

vii

525B

Users Manual

viii

Introduction

Your Fluke 525B Temperature/Pressure Calibrator (referred to as the Calibrator) is
an instrument designed to meet the demands of your process tools calibration
workload.

In addition to the functions in Table 1-1, the Calibrator has the following features
and functions.

• Two line backlit LCD display

• 5-way binding posts

• IEEE 488.2 parallel interface

• RS-232 serial interface

Contacting Fluke

To order accessories or get the location of the nearest Fluke distributor or Service
Center, call:

Chapter 1

Getting Started

• USA: 1-888-99-FLUKE (1-888-993-5853)

• Canada: 1-800-36-FLUKE (1-800-363-5853)

• Europe: [phone]

• Japan: [phone]

• Singapore: [phone]

• Anywhere in the world: [phone]

Or, visit Fluke’s Web site at www.fluke.com.
To register your product, visit register.fluke.com.

1-1

525B

Users Manual

Table 1-1. Summary of Input and Output Functions

Function Input Output

dc V None 0 V to 100 V

dc mA None 0 to 100 mA
Resistance 0 to 4000 Ω (4-wire) 5 to 4000 Ω (2-wire)

Thermocouple Yes Yes

RTD Yes Yes

Pressure Yes No

Standard Equipment

The items listed below are included with your Calibrator. If the Calibrator is
damaged or something is missing, contact the place of purchase immediately. To
order replacement parts or spares, see the replacement parts list in Chapter 6.

• 525B Getting Started Guide, Part No. 3064079

• 525B CD-ROM (contains the 525B Users Manual and 525B Getting Started

Guide), Part No. 3064087

• Power Cord (120 V cord, Part No.1618621 or 240 V cord, Part No. 769422)

• Thermocouple Shorting Jumper, Part No. 610747

Options and Accessories

For more information about these accessories and their prices, contact your Fluke
representative.

• 5520A – 525A Leads kit

• Y525 Rack Mount kit

• Fluke 700 and 525A-P series pressure modules

• MET/CAL with 525B Function Select Code (FSC)

• MET/CAL 525B calibration procedure

Safety Information

This Calibrator complies with IEC 61010, ANSI/ISA-S82.01-1994, CAN/CSA­C22.2 No. 1010.1-92. Use the Calibrator only as specified in this manual,
otherwise the protection provided by the Calibrator may be impaired.

CAT II equipment is designed to protect against transients from energy-consuming
equipment supplied from the fixed installation, such as TVs, PCs, portable tools,
and other household appliances.

1-2

Getting Started
Safety Information

A Warning statement identifies hazardous conditions and actions that could cause
bodily harm or death.

A Caution statement identifies conditions and actions that could damage the
Calibrator or the equipment under test.

International symbols used on the Calibrator and in this manual are explained in
Table 1-2.

Warning

To avoid possible electric shock or personal injury, follow these guidelines:

• Use the Calibrator only as specified in this manual, or the protection provided by

the Calibrator might be impaired.

• Inspect the Calibrator before using it. Do not use the Calibrator if it appears

damaged. Look for cracks or missing plastic. Pay particular attention to the
insulation around the connectors.

• Have the Calibrator serviced only by qualified service personnel.

• Do not apply more than the rated voltage between the terminals, as marked on

the Calibrator, or between any terminal and earth ground.

• Always use the power cord and connector appropriate for the voltage and outlet

of the country or location in which you are working.

1

• Never operate the Calibrator with the cover removed or the case open.

• Never remove the cover or open the case of the Calibrator without first removing

the power source.

• Use caution when working with voltages above 30 V ac rms, 42 V ac peak, or 60

V dc. These voltages pose a shock hazard.

• Use only the replacement fuse(s) specified in this manual.

• Use the proper terminals, function, and range for your measurements.

• Do not operate the Calibrator around explosive gas, vapor, or dust.

• When servicing the Calibrator, use only specified replacement parts.

1-3

525B

Users Manual

Table 1-2. Symbols Used on the Calibrator












AC (Alternating Current)

DC (Direct Current)

Pressure

Chassis protective ground

Important Information. See
manual.

Hazardous voltage. Risk of
electric shock











Earth ground

Resistance

Conforms to European Union
directives

Canadian Standards Association,
NRTL

International ON/OFF symbol.

1-4

Getting Started
Getting Acquainted with the Calibrator

Getting Acquainted with the Calibrator

Input and Output Terminals

Figure 1-1 shows the Calibrator input and output terminals and explains their use.

1

2

VOLTS

100mA MAX

OUTPUT

1

100V MAX

20V PK

MAX

INPUT

20V PK

MAX

HI

LO

4W RTD

HI

LO

6

mA

RTD

HI

LO

SENSE

5

TC

INPUT/OUTPUT

20V PK

MAX

3

ZERO

9

C / F

6

AUTOSET

3

•

TYPE

UNITS

SHIFT

ENTER

CE

STBY

OPR

VOLTS

TC

mA

RTD

OUTPUT

INPUT

8

7

CJC SETUP

5

4

SET RECALL

2

1

LOCAL EXP

RNG LOCK

/

0

4

fcn08f.eps

No Description

 Terminals used to output DC Volts.

 Terminals used to output DC current.

 Terminals used to simulate RTDs and resistance.

 Terminal for thermocouple input and simulation. The terminal accepts a miniature

polarized thermocouple plug with flat, in-line blades spaced 7.9 mm (0.312 in) center
to center.

 Pressure module input.

 Input terminals used to measure 4-wire RTD and resistance.

Figure 1-1. Input and Output Terminals and Connectors

1-5

525B

Users Manual

Using the Keys

Figure 1-2 shows the Calibrator pushbuttons and Table 1-3 explains their use.
Other function keys are shown in Figure 1-3 and described in Table 1-4.

32

4

5

6

7

8

9

ZERO

C / F

TYPE

UNITS

SHIFT

9

6

3

ENTER

•

CE

1

STBY

OPR

VOLTS

OUTPUT

RNG LOCK

TC

mA

RTD

INPUT

8

7

CJCSETUP

5

4

SET RECALL

2

1

LOCAL EX P

/

0

AUTOSET

10

fcn09f.eps

Figure 1-2. Pushbuttons

1-6

Getting Started
Getting Acquainted with the Calibrator

Table 1-3. Pushbutton Usage

No Name Description

1

































 

 





Cycles the Calibrator through Standby and Operate
modes.

Toggles between DC voltage and DC current modes.

Toggles between the current thermocouple and current
RTD.

Selects the pressure measurement mode.

Selects a thermocouple or RTD type. For pressure
measurement, this is used to select the pressure
conversion units.

Selects the alternate function above the numeric keys.

• Increases or decreases the output level.

• Also used to adjust LCD contrast and brightness and

to select options on the Interface and Address
menus.

Selects a different digit to change.

CE (Clear Entry) clears a partially completed keypad entry
from the display. The display reverts to the last known
good entry.

Loads a newly entered output value into the Calibrator.
The new value is an entry from the numeric keypad. Also
used when entering custom RTD coefficients and when
you adjust the display or contrast.

1-7

525B

Users Manual

STBY

OPR

6

VOLTS

mA

5

OUTPUT

7

4

4

3

SET RECALL

1

2

RNG LOCK

/

TC

RTD

INPUT

ZERO

8

CJCSETUP

C / F

5

AUTOSET

2

LOCAL EXP

0

7

TYPE

UNITS

9

6

3

•

SHIFT

8

9

ENTER

1

10

12

11

Figure 1-3. Calibrator Function Keys

Table 1-4. Function Keys

No Name Description





RNG LOCK



SET



Activates/deactivates the autorange feature of the Calibrator in
Voltage source modes.

Used to program a setpoint step for any output mode.
Key in the desired output and press  . SETPOINT # appears

on the display. Select a setpoint number from 1 to 9. The output you
entered can now be recalled or used in the AUTOSET key
described later in this manual.

Each TC type, each RTD/OHMS type, mA, and Volts each have 9
programmable setpoints.



CJC



Toggles between the internal and external cold junction reference
locations.

fcn11f.eps

1-8

Getting Started
Getting Acquainted with the Calibrator

Table 1-4. Function Keys (cont)

No Name Description













SETUP



OUTPUT



INPUT



ZERO



°C/°F



AUTOSET



Press  to advance through the LCD Backlight, Interface, and
Address menus.

• Use  and  to adjust LCD backlight when the LCD menu is

displayed.

• Use  and  to toggle between Serial and GPIB interface when

the Interface menu is displayed.

• Use  and  to scroll from Address:1 to Address 30 when the

address menu is displayed.

Selects Output mode.

Selects Input mode.

Zeros the pressure module reading when in Pressure Measurement
mode.

Zeros the thermocouple TC mV/°C offset when in TC Measurement
mode.

Toggles between Centigrade and Fahrenheit when you are using
the TC or RTD functions.

AUTOSET runs through the setpoints you entered using the SET
function. Press  . AUTO SET POINT? appears on the
display.

Enter a number between 1 and 9 that corresponds to the number of
setpoints being used. DWELL TIME 5-500? appears on the display.
Dwell time is the number of seconds between each setpoint. The
output cycles through each setpoint and then reverses the order.
For example, if 5 is entered for the number of setpoints, the
Calibrator cycles through setpoints 1, 2, 3, 4, 5 and then reverses to
setpoints 4, 3, 2, and 1.

1

Caution

Setpoints of 30 V or greater will not go to standby
when you use this feature.



EXP



Enters an exponent when you define a custom RTD.

1-9

525B

Users Manual

No Name Description





Display Error Messages

Table 1-5 lists informative messages that may appear on the front panel display.
An explanation of each message is also provided.

RECALL



LOCAL



Table 1-4. Function Keys (cont)

Used to recall a programmed set point.
Press  . RECALL SPT # appears on the display. Enter the

number of the output setpoint that you want to use. The output will
then be programmed to the setpoint you entered.

Used to regain local control of the Calibrator. If you set the
Calibrator to a remote state using the remote commands, all the
front panel keys are locked out except the Local key. When you
press the Local key, the front panel is unlocked.

Note

This function does not work when you set the Calibrator using the
Remote with Lockout command. In Remote with Lockout mode,
ALL keys are locked out and the Local key will not unlock the
front panel

.

Table 1-5. Display Error Messages

Message Explanation

OVER RANGE May be displayed in all output modes if you enter a value from the

front panel keypad that exceeds the output range of the function.

OVER LOAD May be displayed in V and mA output modes when the current is

exceeded for volts and the resistance is exceeded for mA.

OL Displayed in Input modes when the measured value exceeds the

upper limit of the range.

This error may also display in Output mode when the range is
locked and an automatically recalled set point exceeds the locked
range. For example, set point 1 (SP1) is set to 1V, SP2 is set to 2V,
and SP3 is set to 100V, the range is locked to 10V range and the
Calibrator is set up to automatically output the first 3 setpoints.
When the Calibrator reaches SP3, the display reads OL, and the
output is set to 0 for the duration of that setpoint.

-OL Displayed in Input modes when the measured value exceeds the
lower limit of the range.

INITIALIZATION FAILURE Displayed when the Calibrator fails to power up properly.

1-10

Getting Started
Getting Acquainted with the Calibrator

Rear Panel View

Figure 1-4 shows the features on the rear panel of the Calibrator and explains their
use.

NO INTERNAL USER SERVICEABLE PARTS
REFER SERVICE TO QUALIFIED
SERVICE PERSONNEL

FLUKE CORPORATION
MADE IN USA

PATENTS PENDING

www.fluke.com

C US

WARNING: FOR FIRE PROTECTION

REPLACE ONLY
WITH A 250V FUSE
OF INDICATED RATING?

MAINS SUPPLY

:

198V - 264V

5x20mm0.25A 250V
5x20mm0.125A 250V

120V: 90V - 132V
240V

FUSE

47Hz - 63Hz

15VA MAX

300V

CAT

CHASSIS
GROUND

1

2

3

1

WARNING: TO AVOID ELECTRIC SHOCK

GROUNDING CONNECTOR IN POWER CORD
MUST BE CONNECTED

7

56

4

fcn10f.eps

No Description

 Power line fuse compartment. Contains fuses and line voltage selector.

 The power switch turns the power on and off.

 A grounded three-prong AC connector that accepts the line power cord.

 The Chassis Ground terminal is internally connected to the ground prong of the AC

connector.

Warning

To avoid shock hazard, connect the factory supplied three­conductor power cord to a properly grounded power outlet. Do not
use a two-conductor adapter or extension cord; this will break the
protective ground connection.

Use the rear panel CHASSIS GROUND terminal as a connection
point for a protective grounding wire if there is any question about
the effectiveness of instrument earth grounding through the line
power cord ground wire.

 Service port used to download new firmware to the Calibrator.

 The IEEE-488 connector is a standard parallel interface for operating the 525B in

remote control as a talker/listener on the IEEE-488 bus.

 The RS-232 connector is used for serial remote control of the 525B.

Figure 1-4. Rear Panel View

1-11

525B

Users Manual

1-12

Using Output Mode

In Output mode, the Calibrator generates calibrated signals for testing and
calibrating process instruments. In Output mode, the Calibrator:

• supplies voltage, current, and resistance

• simulates the output of RTD and TC temperature sensors

The

OVER RANGE message displays if you enter an invalid output

using the keypad. If you enter an out-of-range value, the Calibrator
reverts to the last known good value. You do not need to press .

When adjusting an output using the   keys, the Calibrator will
not display or let you enter an out-of-range value.

Chapter 2

Using Output Mode

Note

Note

The figures is this chapter show how to connect to a Fluke 725
Multifunction Process Calibrator. For other instruments, refer to the
users manual for connection instructions.

2-1

525B

Users Manual

Simulating Thermocouple Temperature

Connect the Calibrator TC input/output to the unit under test (UUT) with
thermocouple wire and the appropriate thermocouple mini-connector. Supported
TC types are listed in Chapter 7. Figure 2-1 shows this connection.

To simulate temperature using a thermocouple (TC):

1. Attach the thermocouple extension wire as shown in Figure 2-1. One pin is

wider than the other. Do not try to force a miniplug in the wrong polarization.

2. Press  until TC is selected.

3. If necessary, press   for TC OUT mode.

4. Press  to select the desired thermocouple type.

5. Use the numeric keypad to enter the desired output value and press . You

can also adjust the output value by pressing  . Press   to select a
different digit to modify.

HI

LO

HI

LO

mA

100mA MAX

SENSE

RTD

HI

LO

TC

INPUT/OUTPUT

TC

20V PK

MAX

STBY
OPR

VOLTS

mA

OUTPUT

INPUT

7

4

SET RECALL

1

LOCAL EXP

RNG LOCK

/

TC
RTD

8

CJC SETUP

5

2

0

TYPE
UNITS

ZERO

C / F

AUTOSET

SHIFT

9

6

3

ENTER

•

OUTPUT

100V MAX

20V PK

MAX

INPUT

20V PK

MAX

VOLTS

4W RTD

Figure 2-1. Connection to Simulate Thermocouple Temperature

CE

fcn07f.eps

2-2

Using Output Mode
Using Output Mode

Simulating Temperature Using Resistance Temperature Detectors (RTDs)

RTDs have a characteristic resistance at specific temperatures. The simulated
output, then, is a resistance value based on the selected temperature and type of
RTD being simulated.

To simulate temperature using a resistance temperature detector:

1. Connect the Calibrator to the unit under test (UUT) as shown in Figure 2-2.

2. Press  until RTD is selected.

3. If necessary, press   for RTD OUT mode.

4. Press  to select the desired RTD type.

5. Use the numeric keypad to enter the desired output value and press . You

can also adjust the output value by pressing  . Press   to select a
different digit to modify.

6. Press  to activate output.

2

725

MULTIFUNCTION CALIBRATOR

RTD

mA

100mA MAX

HI

HI

LO

LO

HI

SENSE

LO

TC

INPUT/OUTPUT

20V PK

MAX

STBY

OPR

VOLTS

TC

mA

RTD

OUTPUT

INPUT

7

CJC SETUP

4

SET RECALL

1

LOCAL EXP

RNG LOCK

/

8

5

2

0

TYPE
UNITS

ZERO

C / F

AUTOSET

SHIFT

9

6

3

ENTER

•

CE

fcn01f.eps

SOURCE

STORE
SETUP

RECALL

MEAS

V mA

LOOP

V mA

TC RTD

ZERO

Hz

C °F

°

100%

25%

25%

0%

OUTPUT

100V MAX

20V PK

MAX

INPUT

20V PK

MAX

VOLTS

4W RTD

Figure 2-2. Connection to Simulate a RTD Temperature

2-3

525B

Users Manual

Simulating Custom RTD Coefficients

The USR_DEF RTD type allows the Calibrator to simulate a custom curve-fit
RTD.

To enter the coefficients for a custom RTD:

1. Press  to select RTD mode.

2. Press  until you get the

3. Press  to enter custom RTD information.

USR_DEF display.

RTD CUSTOM (1-5) appears on

the Calibrator display. You can store up to five custom RTD definitions on the
Calibrator.

4. Press a number key to specify the RTD you want to define (1-5). You can

press  to step through definitions without changing the values.

5. When the

SET/RECALL display appears, press  to define a custom RTD

coefficient.

6. Enter the

7. Enter the

8. Enter the nominal resistance (R

MIN TEMP and press .
MAX TEMP and press .

) and press .

0

9. Enter the temperature coefficients and press . Press   to enter a

positive or negative exponent for the coefficient.

To use a custom RTD:

1. Press  to enter RTD mode.

2. Press  until you get the

3. Press  to use custom RTD information.

USR_DEF display.

RTD CUSTOM (1-5) appears on the

Calibrator display. You can store up to five custom RTD definitions on the
Calibrator.

2-4

4. Press a number key to select the RTD you want to use (1-5).

5. When the

SET/RECALL display appears, press  to recall and use the

selected RTD.

Using Output Mode
Using Output Mode

Default RTD Coefficients

The USR_DEF function of the calibrator uses the Calendar-Van Dusen equation
for outputting and measuring custom RTDs. The C coefficient is only used for the
subrange –260 to 0 degrees Celsius. Only the A and B coefficients are needed for
the subrange 0 to 630 degrees. The R0 is the resistance of the probe at 0 degrees
Celsius. All of the USR_DEF will be set to PT385 as shown in Table 2-1.

Table 2-1. Default RTD Coefficients

Sub range R0 Coefficient A Coefficient B Coefficient C

USR_DEF1 0 to 630 100 3.908X10-3 -5.775e-7

USR_DEF2 -260 to 0 100 3.908X10-3 -5.775e-7 -4.183e-12

USR_DEF3 0 to 630 100 3.908X10-3 -5.775e-7

USR_DEF4 -260 to 0 100 3.908X10-3 -5.775e-7 -4.183e-12

USR_DEF5 0 to 630 100 3.908X10-3 -5.775e-7

If other types of RTDs are required, Table 2-2 shows the coefficients for types
PT391 and PT392. The C coefficient is only used for temperatures below 0
degrees Celsius.

2

Table 2-2. Other Commonly Used RTDs

RTD Type Coefficient A Coefficient B Coefficient C

PT392 3.9848X10-3 -5.87X10-7 -4X10-12

PT391 3.9692X10-3 -5.8495X10-7 -4.2325X10-12

The SPRT function of the calibrator uses ITS-90 standard coefficients for
measuring a SPRT. Since the five coefficients are deviations all of them will be set
to 0.

The coefficients A- and B- represent the A4 and B4 coefficient, obtained when the
SPRT is calibrated at the triple points of argon, mercury and water. This covers the

83.8058K to 273.16K subrange. Coefficients A, B and C can represent different
coefficients based on which subranges of the SPRT has been calibrated. For
example, if the 273.15K to 933.473K subrange was used, A, B and C would
represent A7, B7 and C7 whereas if the 273.15K to 692.67K subrange was used, A
and B would represent A8 and B8 and C=0.

2-5

525B

Users Manual

Entering Custom Standard Platinum Resistance Thermometer (SPRT) Coefficients

To enter coefficients for a custom SPRT:

1. Press  to enter RTD mode.

2. Press  until you get the

3. Enter the

4. Enter the

MIN TEMP and press .
MAX TEMP and press .

5. Enter the nominal resistance (R

RTD SPRT display and press .

) and press .

0

6. Enter the temperature coefficients and press . Press   to enter a

positive or negative exponent for the coefficient.

2-6

Using Output Mode
Using Output Mode

Output DC Voltage

The Calibrator is a fully programmable precision source of DC voltage from 0 V
to 100 V. The Calibrator can only output positive (+) values.

To output DC voltage:

1. Connect the Calibrator to the UUT as shown in Figure 2-3.

2. Press  for V out display.

3. Use the numeric keypad to enter the desired output value and press . You

can also adjust the output value by pressing  . Press   to select a
different digit to modify.

4. Press  to activate output.

Note

For safety purposes, the Calibrator resets to standby when output is
set to 30 V or greater.

2

725

MULTIFUNCTION CALIBRATOR

RTD

mA

100mA MAX

HI

HI

LO

LO

HI

SENSE

LO

TC

INPUT/OUTPUT

20V PK

MAX

STBY
OPR

VOLTS

TC

mA

RTD

OUTPUT

INPUT

7

CJC SETUP

4

SET RECALL

1

LOCAL EXP

RNG LOCK

/

8

5

2

0

TYPE
UNITS

ZERO

C / F

AUTOSET

SHIFT

9

6

3

ENTER

•

CE

fcn02f.eps

MEAS

SOURCE

STORE

SETUP

RECALL

V mA

LOOP

V mA

TC RTD

ZERO

Hz

C °F

°

100%

25%

25%

0%

OUTPUT

100V MAX

20V PK

MAX

INPUT

20V PK

MAX

VOLTS

4W RTD

Figure 2-3. Connection for Setting DC Voltage Output

2-7

525B

Users Manual

Output Resistance

To output resistance:

1. Connect the Calibrator to the UUT as shown in Figure 2-4.

2. Press  until RTD mode is selected.

3. If necessary, press   for RTD OUT mode.

4. Press  to select the appropriate ohms output range (400 or 4000 ohms).

5. Use the numeric keypad to enter the desired output value and press . You

6. Press  to activate output.

can also adjust the output value by pressing  . Press   to select a
different digit to modify.

Note

If the input current is excessive, the Calibrator will beep, display the
message

OVER LOAD, and enter Standby mode. You will need to

check the input current and change it accordingly. Resistance
specifications are listed in Chapter 7.

2-8

MEAS

SOURCE

STORE
SETUP

RECALL

725

V mA

LOOP

V mA

TC RTD

MULTIFUNCTION CALIBRATOR

ZERO

VOLTS

OUTPUT

Hz

C °F

°

100%

25%

25%

0%

100V MAX

20V PK

MAX

INPUT

20V PK

MAX

4W RTD

RTD

mA

100mA MAX

HI

HI

LO

LO

HI

SENSE

LO

TC

INPUT/OUTPUT

20V PK

MAX

STBY

OPR

VOLTS

mA

RTD

OUTPUT

INPUT

7

CJC SETUP

4

SET RECALL

1

LOCAL EXP

RNG LOCK

/

TC

8

5

2

0

TYPE

UNITS

ZERO

C / F

AUTOSET

SHIFT

9

6

3

ENTER

•

CE

fcn01f.eps

Figure 2-4. Connection for Setting Resistance Output