Fluke 726 Service Manual

®

724/725/726

Calibrators

Calibration Manual

PN 667581

September 1999 Rev. 2, 2/06

© 1999, 2000, 2006 Fluke Corporation. All rights reserved. Printed in USA All product names are trademarks of their respective companies.

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 three years 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	Fluke Europe B.V.
P.O. Box 9090	P.O. Box 1186
Everett, WA 98206-9090	5602 BD Eindhoven
U.S.A.	The Netherlands

11/99

Table of Contents

Title	Page
Introduction........................................................................................................	1
Contacting Fluke................................................................................................	1
Read First – Safety Information.........................................................................	2
International Symbols ........................................................................................	3
Specifications.....................................................................................................	4
DC Voltage Measurement (724 and 725)......................................................	4
DC Voltage Measurement and Source (726).................................................	4
DC Voltage Source (724 and 725) ................................................................	4
DC mA Measurement and Source (724 and 725)
(Measurement only for 724).......................................................................	4
DC mA Measurement and Source (726) .......................................................	5
Ohms Measurement (724 and 725) ...............................................................	5
Ohms Measurement (726) .............................................................................	5
Ohms Source (724 and 725) ..........................................................................	5
Ohms Source (726)........................................................................................	6
Frequency Measurement (725)......................................................................	6
Frequency Measurement (726)......................................................................	6
Frequency Source (725) ................................................................................	6
Frequency Source (726) ................................................................................	7
Millivolt Measurement and Source (724 and 725)........................................	7
Temperature, Thermocouples (724 and 725).................................................	7
Temperature, Thermocouples (726) ..............................................................	8
Temperature, RTD Ranges, and Accuracies (724 and 725) ..........................	9
RTD Accuracy (Read and Source) (ITS-90) (726)........................................	10
Loop Power Supply .......................................................................................	11
Pressure Measurement (725 and 726) ...........................................................	11
Pulse Read and Pulse Source (726) ...............................................................	11
Pressure Units Availability (725) ..................................................................	11
General Specifications...................................................................................	12
Cleaning the Calibrator......................................................................................	12
Replacing the Batteries ......................................................................................	12
Fuses ..................................................................................................................	13
Remote Control Interface (725 and 726) ...........................................................	14
Serial Command List (726)................................................................................	17
Required Equipment ..........................................................................................	22
Performance Tests..............................................................................................	24
Preparing for the Performance Tests .............................................................	24
Upper Display Voltage Measurement Tests ..................................................	25
Lower Display mV/TC Measurement Tests ..................................................	26
Lower Display Voltage Measurement Tests..................................................	27
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Upper Display mA Measurement Tests.........................................................	28
Lower Display mA Measurement Tests (725 and 726).................................	29
Lower Display Frequency Measurement Test (725 and 726) .......................	30
Lower Display Frequency Source Test (725 and 726) ..................................	31
Lower Display 4-Wire Resistance Measurement Tests.................................	32
Lower Display 3-Wire RTD Measurement ...................................................	33
Lower Display Thermocouple Measurement Tests.......................................	34
Lower Display Thermocouple Source Test ...................................................	35
Lower Display mA Source Tests (725 and 726) ...........................................	36
Lower Display mV Source Tests...................................................................	37
Lower Display Voltage Source Tests ............................................................	37
Lower Display Ohms Source Tests ...............................................................	38
Pressure Module Input (725/726)..................................................................	39
Calibration Adjustment......................................................................................	39
Setup..............................................................................................................	39
Initiating Communication (724 and 725) ......................................................	40
Calibration Adjustment Procedures (724 and 725) .......................................	41
Cal Volts Input ..........................................................................................	41
Cal Volts Output .......................................................................................	42
Cal mA Input (Fluke 725 Only) ................................................................	43
Cal mA Output (725 Only) .......................................................................	44
Cal mV Input.............................................................................................	45
Cal mV Output ..........................................................................................	46
Cal Thermocouples ...................................................................................	47
Cal Ohms Hi Source..................................................................................	48
Cal Ohms Low Source ..............................................................................	49
Cal RTD Low Range.................................................................................	50
Cal RTD Hi Range ....................................................................................	51
Cal ISO Volts ............................................................................................	52
Cal ISO mA...............................................................................................	53
Calibration Adjustment Procedures (726) .....................................................	54
Initiating Communication .........................................................................	54
Calibrating Isolated mA Input...................................................................	55
Calibrating Isolated Voltage Input ............................................................	56
Calibrating mA Input ................................................................................	57
Calibrating mA Output..............................................................................	58
Calibrating Voltage Input..........................................................................	59
Calibrating Voltage Output .......................................................................	60
Calibrating Low Ohms Source..................................................................	61
Calibrating High Ohms Source .................................................................	62
Calibrating Ohms Measure........................................................................	63
Calibrating Thermocouple mV Output .....................................................	64
Calibrating Thermocouple mV Input ........................................................	65
Calibrating Thermocouple CJC:................................................................	66
Replaceable Parts...............................................................................................	67

ii

List of Tables

Table	Title	Page
1.	International Symbols ............................................................................................	3
2.	Upper Display Remote Commands (725) ..............................................................	14
3.	Lower Display Remote Commands (725)..............................................................	15
4.	Remote Commands for Sensor Selection (725) .....................................................	16
5.	Serial Command List-726 ......................................................................................	17
6.	Required Equipment and Software ........................................................................	23
7.	Upper Display Voltage Readings...........................................................................	25
8.	Lower Display mV Readings .................................................................................	26
9.	Lower Display Voltage Readings ..........................................................................	27
10.	Upper Display mA Readings..................................................................................	28
11.	Lower Display mA Readings .................................................................................	29
12.	Lower Display 4-Wire Resistance Readings..........................................................	32
13.	Type J Thermocouple Readings.............................................................................	34
14.	Lower Display Thermocouple Source Readings....................................................	35
15.	Lower Display mA Source Readings .....................................................................	36
16.	Lower Display mV Source Readings .....................................................................	37
17.	Lower Display Voltage Source Readings ..............................................................	37
18.	Lower Display Ohms Source Readings..................................................................	38
19.	Replacement Parts ..................................................................................................	67

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iv

List of Figures

Figure	Title	Page
1.	Replacing the Batteries and Replaceable Fuses .....................................................	13
2.	Upper Display Voltage Test Connections..............................................................	25
3.	Lower Display mV and Voltage Test Connections................................................	26
4.	Upper Display mA Test Connections.....................................................................	28
5.	Lower Display mA Test Connections ....................................................................	29
6.	Lower Display Frequency Test Connections .........................................................	30
7.	Lower Display Frequency Source Test Connections .............................................	31
8.	Lower Display 4-Wire Resistance Test Connections.............................................	32
9.	Lower Display 3-Wire Resistance Test Connections.............................................	33
10.	Lower Display Thermocouple Test Connections...................................................	34
11.	Lower Display mA Source Test .............................................................................	36
12.	Lower Display Ohms Source Test Connections....................................................	38
13.	Volts Input Calibration Connections......................................................................	41
14.	Volts Output Calibration Connections ...................................................................	42
15.	mA Input Calibration Connections ........................................................................	43
16.	mA Output Calibration Connections......................................................................	44
17.	mV Input Calibration Connections ........................................................................	45
18.	mV Output Calibration Connections......................................................................	46
19.	Thermocouples Calibration Connections ...............................................................	47
20.	Ohms Hi Source Calibration Connections .............................................................	48
21.	RTD Low Range Calibration Connections ............................................................	50
22.	ISO Volts Calibration Connections........................................................................	52
23.	ISO mA Calibration Connections ..........................................................................	53
24.	Isolated mA Input Calibration Connections...........................................................	55
25.	Isolated Voltage Input Calibration Connections ....................................................	56
26.	mA Input Calibration Connections ........................................................................	57
27.	mA Output Calibration Connections......................................................................	58
28.	Voltage Input Calibration Connections..................................................................	59
29.	Voltage Output Calibration Connections ...............................................................	60
30.	Low Ohms Source Calibration Connections ..........................................................	61
31.	High Ohms Source Calibration Connections .........................................................	62
32.	Ohms Measure Calibration Connections................................................................	63
33.	Thermocouple mV Output Calibration Connections..............................................	64
34.	Thermocouple mV Input Calibration Connections ................................................	65
35.	Thermocouple CJC Calibration Connections.........................................................	66
36.	Replacement Parts ..................................................................................................	68
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vi

Introduction

XWWarning

The information provided in this manual is for the use of qualified personnel only. Do not perform the verification tests or calibration procedures described in this manual unless you are qualified to do so.

This Calibration Manual provides the following information for the Fluke 724 Temperature Calibrator and the Fluke 725 and 726 Multifunction Process Calibrators (also referred to as "the Calibrator" and/or “the UUT”):

•Precautions and safety information

•Equipment required for performance tests and calibration

•Specifications

•Basic maintenance (cleaning, batteries, and fuses)

•Instructions for using the remote control interface

•Performance test procedures

•Calibration procedures

•List of replaceable parts

For complete operating instructions, refer to the appropriate Users Manual (located on the CD-ROM shipped with the instrument).

Caution

The Calibrator contains parts that can be damaged by static discharge. No procedure in this document requires the case to be opened. If you do so, follow the standard practices for handling static sensitive devices.

Contacting Fluke

To locate an authorized service center, visit us on the World Wide Web at www.fluke.com or call Fluke using any of the following numbers:

•USA: 1-888-44-FLUKE (1-888-443-5853)

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

•Europe: [phone]

•Japan: [phone]

•Singapore: [phone]

•Anywhere in the world: [phone]

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Read First – Safety Information

In this calibration manual, a Warning identifies conditions and actions that pose hazard(s) to the user. A Caution identifies conditions and actions that may damage the Calibrator or the test instruments.

XWWarnings

To avoid possible electric shock or personal injury:

•DO NOT use the Calibrator if it looks damaged.

•Follow all safety procedures for the test and calibration equipment you use.

•Examine the Calibrator before use. Look for cracks in the case, missing plastic, or damaged insulation around the connectors.

•Inspect the test leads for damaged insulation or exposed metal. Check for test lead continuity. Replace damaged test leads as necessary.

•Do not use the Calibrator if it operates abnormally. Protection may be impaired. When in doubt, have the instrument serviced.

•Do not apply more than the rated voltage, as marked on the Calibrator, between terminals or between any terminal and earth ground.

•Never touch the probes to a voltage source when the test leads are plugged into the current terminals.

•Select the proper function and range for each measurement.

•Disconnect the test leads before changing to another measure or source function.

•When using probes, keep fingers behind the finger guards on the probes.

•Use caution when working above 30 V ac rms, 42 V ac peak, or 60 V dc. Such voltages pose a shock hazard.

•Connect the common lead (COM) before connecting the live test lead. When disconnecting test leads, disconnect the live test lead first.

•Always place the 5520A calibrator in Standby (STBY) mode between tests and before handling the test connections or cables.

•Remove test leads from the Calibrator before opening the battery door.

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

•During normal operation, only use four properly installed AA batteries to power the Calibrator.

•Make sure the battery door is closed and latched before you operate the Calibrator.

•During calibration, use only specified calibration equipment listed in Table 6.

(Continued on the next page)

2

Calibrators

International Symbols

XWWarnings (cont)

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

•To avoid false readings, which can lead to possible electric shock or personal injury, replace the batteries as soon as the low battery indicator (B) appears.

Caution

To avoid possible damage to the Calibrator or to the test instruments:

•Disconnect the power and discharge all high voltage capacitors before testing resistance, diodes, or continuity.

•Use the proper jacks, function, and range for each measurement or sourcing application.

International Symbols

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

Table 1. International Symbols

Symbol	Meaning	Symbol	Meaning
B	Alternating current	J	Earth ground
F	Direct current	O	ON/OFF
D	Alternating or direct current	P	Conforms to European Union directives
f	Pressure	B	Battery
W	Refer to the manual.	)	Conforms to relevant Canadian
	Important information.		Standards Association directives
X	Take appropriate precautions.	T	Double insulated
	Hazardous voltage may be present.
~	Do not dispose of this product as unsorted municipal waste. Contact Fluke or a qualified
	recycler for disposal.

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Specifications

Performance and accuracy are specified for one year after calibration, at operating temperatures of +18 °C to +28 °C (64 °F to 82 °F), in relative humidity to 90 %, after a

5 minute warm up period.

				Note
	A “count” is the amount by which the least significant digit can vary.
DC Voltage Measurement (724 and 725)
	Range	Resolution		Accuracy (% of Reading + Counts)
30	V (upper display)	0.001 V		0.02 % + 2
20	V (lower display)	0.001 V		0.02 % + 2
90 mV (lower display)		0.01 mV		0.02 % + 2

Temperature coefficient -10 °C to +18 °C, 28 °C to 55 °C: ±0.005 % of range per °C

DC Voltage Measurement and Source (726)

	Range	Minimum	Maximum		Accuracy,
					(% of Reading + Floor)
30	V (upper display)	0.000 V	30.000 V		0.010 % + 2 mV
20	V (lower display)	0.000 V	20.000 V		0.010 % + 2 mV
20	V (Source)	0.000 V	20.000 V		0.010 % + 2 mV
100 mV (Source)		0.000 V	100.000 mV		0.010 % + 10 µV
90 mV (Read)		0.000 V	90.000 mV		0.010 % + 10 µV
Maximum current output in voltage ranges is 1 mA with an output impedance of					≤ 1 Ω

DC Voltage Source (724 and 725)

Range	Resolution	Accuracy (% of Reading + Counts)
100 mV	0.01 mV	0.02 % + 2
10 V	0.001 V	0.02 % + 2

Temperature coefficient -10 °C to +18 °C, 28 °C to 55 °C: ±0.005 % of range per °C

Maximum load: 1 mA

DC mA Measurement and Source (724 and 725) (Measurement only for 724)

Range	Resolution	Accuracy ( % of Reading + Counts)
24 mA	0.001 mA	0.02 % + 2

Temperature coefficient -10 °C to +18 °C, +28 °C to 55 °C: ±0.005 % of range per °C

Drive capability: 1000 Ω at 20 mA

4

Calibrators

Specifications

DC mA Measurement and Source (726)

			Accuracy,
Range	Minimum	Maximum	(% of Reading +
			Floor)
mA Read (Upper Display)	0.000	24.000	0.010 % + 2 µA
mA Read (Lower Display)	0.000	24.000	0.010 % + 2 µA
mA Source	0.000	24.000	0.010 % + 2 µA
Maximum load on, mA source is 1 kΩ. With the HART resistor on, maximum load is 750 Ω.
Voltage input range on simulate mode is 5 to 30 V
Ohms Measurement (724 and 725)

Ohms Range	Accuracy, 4-Wire	Accuracy*, 2-Wire, or 3-Wire
0 Ω to 400 Ω**	±0.1 Ω	±0.15 Ω
400 Ω to 1.5 kΩ	±0.5 Ω	±1.0 Ω
1.5 Ω to 3.2 kΩ	±1 Ω	±1.5 Ω

Excitation Current: 0.2 mA

Maximum input voltage: 30 V

Temperature coefficient -10 °C to +18 °C, +28 °C to 55 °C: ±0.005 % of range per °C

* 2-wire: Does not include lead resistance.

** For Firmware V1.7 or lower, the lowest range is 15 Ω to 400 Ω.

3-wire: Assumes matched leads with a total resistance not exceeding 100 Ω.

Ohms Measurement (726)

	Ohms Range	Minimum	Maximum	Accuracy
				(% of Reading + Floor)
	Ohms Read (low)	0.00	400.00	0.015 % + 0.05 Ω
	Ohms Read (high)	400.0	4000.0	0.015 % + 0.5 Ω

Ohms Source (724 and 725)

Ohms Range	Excitation Current from Measurement Device	Accuracy
15 Ω to 400 Ω	0.15 mA to 0.5 mA	±0.15 Ω
15 Ω to 400 Ω	0.5 mA to 2 mA	±0.1 Ω
400 Ω to 1.5 kΩ	0.05 mA to 0.8 mA	±0.5 Ω
1.5 Ω to 3.2 kΩ	0.05 mA to 0.4 mA	±1 Ω

Temperature coefficient -10 °C to +18 °C, 28 °C to 55 °C: ±0.005 % of resistance range per °C

Resolution

15 to 400 Ω	0.1 Ω
400 to 3.2 kΩ	1 Ω

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Ohms Source (726)

				Excitation Current from	Accuracy
	Ohms Range	Minimum	Maximum		(% of Reading +
				Measurement Device
					Floor)
	Ohms Source (low)	5.0	400.0	0.1 to 0.5 mA	0.015 % + 0.1 Ω
		5.0	400.0	0.5 to 3 mA	0.015 % + 0.05 Ω
	Ohms Source (high)	400	1500	0.05 to 0.8 mA	0.015 % + 0.5 Ω
		1500	4000	0.05 to 0.4 mA	0.015 % + 0.5 Ω

Unit is compatible with smart transmitters and PLCs.

Frequency response is ≤ 5 mS

Frequency Measurement (725)

Range	Resolution	Accuracy
2.0 to 1000.0 CPM	0.1 CPM	± (0.05 % + 1 count)
1 to 1000 Hz	0.1 Hz	± (0.05 % + 1 count)
1.0 to 10.0 kHz	0.01 kHz	± (0.05 % + 1 count)

Sensitivity: 1 V peak-to-peak minimum

Waveform: Squarewave

Frequency Measurement (726)

			Accuracy
Range	Minimum	Maximum	(% of Reading +
			Floor)
CPM Read	2.0	1000.0	0.05 % + 0.1 CPM
Hz Read	1.0	1000.0	0.05 % + 0.1 Hz
KHz Read	1.00	15.00	0.05 % + 0.01 KHz

Frequency Source (725)

Range	Resolution	Accuracy (% of output frequency)
2.0 to 1000.0 CPM	0.1 CPM	± 0.05 %
1 to 1100 Hz	1 Hz	± 0.05 %
1.0 to 10.0 kHz	0.1 kHz	± 0.25 %

Waveform: 5 V p-p squarewave, -0.1 V offset

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Calibrators

Specifications

Frequency Source (726)

	Range	Minimum	Maximum	Accuracy
	CPM Source	2.0	1000	0.05 %
	Hz Source	1.0	1000.0	0.05 %
	KHz Source	1.0	10.00	0.25 %
		10.00	15.00	0.50 %

Millivolt Measurement and Source (724 and 725)

Range*	Resolution	Accuracy
-10 mV to +75 mV	0.01 mV	±(0.025 % + 1 count)

Maximum input voltage: 30 V

Temperature coefficient -10 °C to +18 °C, 28 °C to 55 °C: ±0.005 % of range per °C

*Select this function by pressing T. The signal is available at the thermocouple miniplug connector.

Temperature, Thermocouples (724 and 725)

Type		Range (°C)	Measure and Source Accuracies (°C)
J		-200 to 0	1.0
		0 to 1200	0.7
K		-200 to 0	1.2
		0 to 1370	0.8
T		-200 to 0	1.2
		0 to 400	0.8
E		-200 to 0	0.9
		0 to 950	0.7
		-20 to 0	2.5
R		0 to 500	1.8
		500 to 1750	1.4
		-20 to 0	2.5
S		0 to 500	1.8
		500 to 1750	1.5
		600 to 800	2.2
B		800 to 1000	1.8
		1000 to 1800	1.4
L		-200 to 0	0.85
		0 to 900	0.7
U		-200 to 0	1.1
		0 to 400	0.75
N*		-200 to 0	1.5
		0 to 1300	0.9
Resolution:
J, K, T, E, L, N, U:		0.1 °C, 0.1 °F
B, R, S:		1 °C, 1 °F

* For Firmware V1.7 or lower, the type N TC has 400 °C as the upper limit.

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Temperature, Thermocouples (726)

	Type	Minimum	Maximum	CJC ON	CJC OFF
				Accuracy	Accuracy
		-210	0.0	0.6	0.4
	J	0.0	800	0.4	0.2
		800	1200	0.5	0.3
		-200	0.0	0.8	0.6
	K	0.0	1000	0.5	0.3
		1000	1372	0.7	0.5
	T	-250	0.0	0.8	0.6
		0.0	400	0.4	0.2
	E	-250	-100	0.8	0.6
		-100	1000	0.4	0.4
	R	-20	0.0	2.0	1.8
		0.0	1767	1.4	1.2
	S	-20	0.0	2.0	1.8
		0.0	1767	1.4	1.2
		600	800	1.4	1.2
	B	800	1000	1.5	1.3
		1000	1820	1.7	1.5
	C	0.0	1000	0.8	0.6
		1000	2316	2.5	2.3
	L	-200	0.0	0.45	0.25
		0.0	900	0.4	0.2
	U	-200	0.0	0.7	0.5
		0.0	600	0.45	0.25
	N	-200	0.0	1.0	0.8
		0.0	1300	0.6	0.4
	XK	-200	800	0.4	0.2
	BP	0.0	800	1.1	0.9
		800	2500	2.3	2.1
				Range	Accuracy
					0.015 % + 10 µV
	Thermocouple in mV read			-10 mV to 75 mV	(% of Reading +
					Floor)
					0.015 % + 10 µV
	Thermocouple in mV source			-10 mV to 75 mV	(% of Reading +
					Floor)
	Maximum current output in voltage ranges is 1 mA with an output impedance of ≤ 1 Ω
	CJC error outside of 23 ± 5 °C is 0.05 °C / °C

8

Calibrators

Specifications

Temperature, RTD Ranges, and Accuracies (724 and 725)

				Accuracy
Type		Range (°C)
			Measure	Measure*
			4-wire (°C)	2- and 3-wire (°C)	Source (°C)
Ni120		-80 to 260	0.2	0.3	0.2
Pt100-385		- 200 to 800	0.33	0.5	0.33
Pt100-392		-200 to 630	0.3	0.5	0.3
Pt100-JIS		-200 to 630	0.3	0.5	0.3
Pt200-385		-200 to 250	0.2	0.3	0.2
		250 to 630	0.8	1.6	0.8
Pt500-385		-200 to 500	0.3	0.6	0.3
		500 to 630	0.4	0.9	0.4
Pt1000-385		-200 to 100	0.2	0.4	0.2
		100 to 630	0.2	0.5	0.2
Resolution:	0.1 °C, 0.1 °F
Allowable excitation current (source): Ni120, Pt100-385, Pt100-392, Pt100-JIS,
Pt200-385: .05 to .80 mA,Pt500-385: 0.05 to 0.80 mA; Pt1000-385: 0.05 to 0.40 mA

RTD Source: Addresses pulsed transmitters and PLCs with pulses as short as 5 ms. SN < 7624001 may need modification for pulses less than 15 ms.

*2-wire: Does not include lead resistance.

3-wire: Assumes matched leads with a total resistance not exceeding 100 Ω.

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RTD Accuracy (Read and Source) (ITS-90) (726)

	Range	Minimum	Maximum	Accuracy
	Ni120 (672)	-80.00	260.00	0.15
		-200.00	100.00	0.15
	Pt100 (385)	100.00	300.00	0.25
		300.00	600.00	0.35
		600.00	800.00	0.45
		-200.00	100.00	0.15
	Pt100 (3926)
		100.00	300.00	0.25
		300.00	630.00	0.35
		-200.00	100.00	0.15
	Pt100 (3916)
		100.00	300.00	0.25
		300.00	630.00	0.35
		-200.00	100.00	0.75
	Pt200 (385)
		100.00	300.00	0.85
		300.00	630.00	0.95
		-200.00	100.00	0.35
	Pt500 (385)
		100.00	300.00	0.45
		300.00	630.00	0.55
		-200.00	100.00	0.15
	Pt1000 (385)
		100.00	300.00	0.25
		300.00	630.00	0.35
	CU10	-10.00	250.00	1.8

Notes: Read Accuracy is based on 4-wire input. For 3-wire input, add ± 0.05 Ω assuming all three RTD leads are matched.

Source Accuracy is based on 0.5 to 3.0 mA excitation current (0.1 mA for pt1000 range)

Resolution: 0.1 °C, 0.1 °F

Allowable excitation current (source): Ni120, Pt100-385, Pt100-392, Pt100-JIS,

Pt200-385: .05 to .80 mA,Pt500-385: 0.05 to 0.80 mA; Pt1000-385: 0.05 to 0.40 mA

RTD Source: Addresses pulsed transmitters and PLCs with pulses as short as 5 ms. SN < 7624001 may need modification for pulses less than 15 ms.

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Calibrators

Specifications

Loop Power Supply

Voltage: 24 V

Maximum current: 22 mA

Short circuit protected

Pressure Measurement (725 and 726)

	Range	Resolution	Accuracy	Units	Mode (726 Only)
				psi, inH2O@4 °C,	Pushing A for 3
				inH2O@20 °C, kPa,	seconds stores
	Determined by	5 digits	Determined by	cmH2O@4 °C,	present pressure
	pressure module		pressure module	cmH2O@20 °C, bar,	value as an offset and
				mbar, kg/cm2, mmHg,	subtracts it from the
				inHg	displayed value.

Pulse Read and Pulse Source (726)

Pulse	Min	Max	Accuracy	Frequency
Source	1	10,000	1 Count	2 CPM to 10 kHz
Read		100,000

Pressure Units Availability (725)

Unit	Availability
psi	Available on all pressure ranges
inH2O	All ranges through 3000 psi
cmH2O	All ranges through 1000 psi
bar	15 psi and above
mbar	All ranges through 1000 psi
kPa	Available on all pressure ranges
inHg	Available on all pressure ranges
mmHg	All ranges through 1000 psi
kg/cm2	15 psi and above

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724/725/726

Calibration Manual

General Specifications

	Operating temperature	-10 °C to 55 °C
	724 and 725
	726	-10 °C to 50 °C
	Storage temperature	- 20 °C to 70 °C
	Stability	± 0.005 % of range/°C outside of 23 ± 5 °C
	Operating altitude	3000 meters above mean sea level
		90 % (10 to 30 °C)
	Relative Humidity (% RH operating without	75 % (30 to 40 °C)
		45 % (40 to 50 °C)
	condensation)
		35 % (50 to 55 °C)
		uncontrolled < 10 °C
	Vibration	Random, 2 g, 5 Hz to 500 Hz
	Safety
	724 and 725	EN 61010-1:1993, ANSI/ISA S82.01-1994; CAN/CSA
		C22.2 No 1010.1:1992
	726	EN50082-1:1992 and EN55022: 1994 Class B Criteria
		A or B CSA C22.2 No 1010.1:1992
	Power requirements	4 AA alkaline batteries
	Protection Class	Pollution Degree II
	Size	96 x 200 x 47 mm (3.75 x 7.9 x 1.86 in)
	Weight	650 gm (1 lb, 7 oz)

Cleaning the Calibrator

XWWarning

To avoid electric shock or damage to the Calibrator, never allow water inside the Calibrator’s case.

If the Calibrator requires cleaning, wipe it down with a cloth that is lightly dampened with water or a mild detergent.

Do not use aromatic hydrocarbons, chlorinated solvents, or methanol-based fluids when cleaning the Calibrator. To avoid damaging the case, never apply solvents to the Calibrator.

Replacing the Batteries

XWWarning

To avoid electric shock, remove the test leads from the Calibrator before opening the battery door. Close and latch the battery door before using the Calibrator.

To avoid false readings, which can lead to possible electric shock or personal injury, replace the batteries as soon as the low battery indicator (B) appears.

When replacing the batteries, always use four new AA batteries. Never mix new and used batteries in the Calibrator.

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Calibrators

Fuses

Four AA alkaline batteries (ANSI/NEDA 15A or IEC LR6) are used to power the

Calibrator. To replace the batteries, refer to Figure 1 and do the following:

1.Turn the Calibrator off, remove the test leads from the terminals, and hold the Calibrator face down.

2.Using a flat-blade screwdriver, turn the battery door screws 1/4-turn counterclockwise and remove the battery door.

3.Remove the batteries, then install new batteries. Be sure to follow the polarity markings shown in the battery compartment.

4.Replace the battery door and secure it by turning the screws 1/4-turn clockwise.

aal01f.eps

Figure 1. Replacing the Batteries and Replaceable Fuses

Fuses

XWWarning

To avoid electrical shock:

•Remove the test leads from the calibrator before opening the battery door. Close and latch the battery door before using the calibrator.

•Use only the specified replacement fuses listed under “Replaceable Parts”.

•Do not allow water into the case.

Over time, the input protection has been modified to increase reliability. There will either be self-resetting fuses, or replaceable fuses in sockets. The self-resetting fuses open when heated by a current overload, and close when they cool down. When an input’s fuse is open, the input’s functions will not work.

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724/725/726

Calibration Manual

The time required for a self-resetting fuse to reset depends on the magnitude of the overload. If a self-resetting fuse does not reset, return the Calibrator to an authorized service center for repair.

If a replaceable fuse has been damaged, it needs to be replaced. The fuses can be removed and checked for resistance. A value of < 10 Ω is good.

The calibrator comes equiped with three 0.2 A 250 V socketed fuses.

•Problems while measuring with the right jacks indicate that F3 may have opened.

•Problems while measuring or sourcing with the center jacks or the TC jacks indicate that F2 may have opened.

•If you can’t measure or source current with the left jacks, F4 may have opened.

To access the fuses, refer to instructions under “Replacing the Batteries”. The fuse compartment is located below the battery compartment. Use needle-nosed pliers to remove them and test them with a multimeter. Replace the fuse with the proper replacement fuse and follow the directions for reassembling the Calibrator. Refer to Figure 1.

Remote Control Interface (725 and 726)

The Calibrator’s serial interface and remote control commands let you use a PC to remotely select Calibrator functions and read the Calibrator’s display. This remote interface is especially useful if you want to write your own calibration software.

The 726 remote control interface is always active.

To activate the 725 remote control interface, proceed as follows:

1.Turn off the UUT; then use the Fluke 700SC serial interface cable to connect the UUT to a serial port on the PC.

2.Start the terminal communication software on the PC. Create a new connection with the following properties:

•Bits per second: 9600

•Data bits: 8

•Parity: None

•Stop bits: 1

•Flow control: None

•Local echo on

3.Hold down the Calibrator’s M button while turning the Calibrator on.

4.Use the commands given in Tables 2 through 4 to remotely control the Calibrator.

	Table 2. Upper Display Remote Commands (725)
Remote Command		Description
i		mA measurement
L		mA Loop Power
E		Voltage measurement
B		Single broadcast of the most recent upper display value and units
(		Single broadcast of most recent upper display value without header or units

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Calibrators

Remote Control Interface (725 and 726)

	Table 3. Lower Display Remote Commands (725)
Remote Command	Description
A	mA measurement
a	mA source
I	mA 2W Sim
V	Voltage measurement
v	Voltage source
M	mV measurement
m	mV source
K	kHz measurement
k	kHz source
H	Hz measurement
h	Hz source
P	CPM measurement
p	CPM source
O	Ohms measurement (default 2W)
o	Select Ohms source
W	2-wire measurement (Ohms and RTDs)
X	3-wire measurement (Ohms and RTDs)
Y	4-wire measurement (Ohms and RTDs)
T	Thermocouple measurement (default Type J). Use “S” command to select a
	sensor type.
t	Thermocouple source (default Type J). Use “S” command to select a sensor type
C	Selects Centigrade ( T/C-RTD)
F	Selects Fahrenheit ( T/C-RTD)
R	RTD measurement mode (default Pt100 385). Use “S” command to select a
	sensor type
r	RTD measurement mode (default Pt100 385). Use “S” command to select sensor
	type.
u	Increment display source value
d	Decrement display source value
<	The < arrow key PC keyboard selects left arrow on 725
>	The > arrow key PC keyboard selects right arrow on 725
0-9	Enter a source value using ASCII characters 0,1,2,...9,-,.terminated by <CR>
	(carriage return)
-,.	The 725 can receive a maximum of 10 characters prior to the carriage return.
<CR>
b	Single Broadcast of most recent lower display value and units
)	Single broadcast of most recent lower display value without header or units.

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Calibration Manual

Table 4. Remote Commands for Sensor Selection (725)

		Selection Entry
Serial Input	No.	Thermocouple Type	RTD Type
S	1	J	Pt100 (3926)
	2	K	Pt100 (385)
	3	T	Pt100 (3916)
	4	E	Pt200 (385)
	5	R	Pt500 (385)
	6	S	Pt1000 (385)
	7	B	Ni120
	8	L	-
	9	U	-
	A	N	-
	B	mV	-

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