Fluke Hart Scientific 1575 Super-Thermometer, Hart Scientific 1590 Super-Thermometer II User Manual

Hart Scientific

1575/1590

Thermometer Readout

User’s Guide

Rev. 5B2802

Fluke Corporation, Hart Scientific Division

799 E. Utah Valley Drive • American Fork, UT 84003-9775 • USA
Phone: [phone] • Telefax: +1.801.763.1010
E-mail: [e-mail]

www.hartscientific.com

Subject to change without notice. • Copyright © 2005 • Printed in USA

Rev. 5B2802

Table of Contents

1 Before You Start . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.1 Symbols Used . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.2 Safety Information . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1.2.1 WARNINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1.2.2 CAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.3 Authorized Service Centers. . . . . . . . . . . . . . . . . . . . . . 3

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

2.1 General Description . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.2 Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.2.1 Measurement Technique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2.2.2 Performance Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2.2.2.1 Lead Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.2.2.2 Thermoelectric EMF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

2.2.2.3 Reactance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.2.2.4 Leakage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.2.2.5 Self-heating. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.2.2.6 Component Drift . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.2.2.7 Noise and Resolution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.2.2.8 Nonlinearity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.2.2.9 Measurement Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.2.2.10 Solid-State Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

3 Specifications and Environmental Conditions . . . . . . . . . 13

3.1 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

3.2 Environmental Conditions. . . . . . . . . . . . . . . . . . . . . . 15

3.3 Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

4 Quick Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

4.1 Unpacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

4.2 Learn About the Features and Components . . . . . . . . . . . . . 17

4.3 2575/2590 Scanner Setup . . . . . . . . . . . . . . . . . . . . . . 17

4.4 Power Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

4.5 Probe Connection . . . . . . . . . . . . . . . . . . . . . . . . . . 17

4.6 Switch the Power On . . . . . . . . . . . . . . . . . . . . . . . . 18

4.7 Measure Temperature . . . . . . . . . . . . . . . . . . . . . . . . 18

5 Parts and Controls . . . . . . . . . . . . . . . . . . . . . . . . 21

5.1 Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

5.2 Back Panel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

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5.3 Front Panel Display . . . . . . . . . . . . . . . . . . . . . . . . . 24

5.4 Front Panel Buttons . . . . . . . . . . . . . . . . . . . . . . . . . 25

6 General Operation . . . . . . . . . . . . . . . . . . . . . . . . 29

6.1 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

6.2 Suggestions for Best Results . . . . . . . . . . . . . . . . . . . . 30

6.2.1 Maintaining Accuracy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

6.2.2 Evaluating Temperature Uncertainty . . . . . . . . . . . . . . . . . . . . . . 32

6.3 Answers to Some Common Questions . . . . . . . . . . . . . . . 33

7 Front Panel Operation . . . . . . . . . . . . . . . . . . . . . . 37

7.1 Channel Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

7.1.1 Measure Input 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

7.1.2 Measure Input 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

7.1.3 Alternate Channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

7.2 Sample Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

7.2.1 Sampling Run/Stop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

7.2.2 Sample N . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

7.2.3 Sample Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

7.2.4 Digital Filter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

7.2.5 Reset Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

7.3 Memory Menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

7.3.1 Store Sample . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

7.3.2 Write Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

7.3.3 View Memory. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

7.3.4 Clear Memory. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

7.3.5 Run/Pause Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

7.4 Probe Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

7.4.1 Select Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

7.4.2 Select Probe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

7.4.3 Edit Probe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

7.4.3.1 Serial Number. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

7.4.3.2 Temperature Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

7.4.3.2.1 ITS-90 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

7.4.3.2.2 IPTS-68 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

7.4.3.2.3 Callendar-Van Dusen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

7.4.3.2.4 Polynomial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

7.4.3.2.5

Thermistor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

7.4.3.2.6 Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

7.4.3.2.7 W(T

7.4.3.2.8 Ratio. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

7.4.3.3 Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

7.4.3.4 Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

7.4.3.5 Standby Current. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

7.4.3.6 Three-wire Offset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

7.4.4 Calibrate Probe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

7.4.4.1 Calibrate TPW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52

7.4.4.2 Calibrate ITS-90 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54

7.4.4.2.1 Calibration Using Only Fixed Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

7.4.4.2.2 Comparison Calibration With Manual Sequencing . . . . . . . . . . . . . . . . . . . . . 56

7.4.4.2.3 Comparison Calibration With Automatic Sequencing . . . . . . . . . . . . . . . . . . . 56

7.4.4.2.4 Calibration Using SPRT Resistance Comparison. . . . . . . . . . . . . . . . . . . . . . 57

7.4.4.2.5 Calibration With W Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

90

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7.4.4.2.6 Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

7.4.4.2.7 Measure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

7.4.4.2.8 Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

7.4.4.2.9 Calculate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

7.4.4.2.10 Print Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

7.4.4.3 1.414 x Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

7.4.4.4 0.707 x Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

7.4.4.5 Conversion Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

7.4.5 Probe Disk. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

7.4.5.1 Save Probe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

7.4.5.2 Read Probe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

7.4.5.3 Save All . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

7.4.5.4 Read All. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

7.4.5.5 Format Disk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

7.5 Display Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

7.5.1 Data/Graph . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

7.5.2 Select Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

7.5.3 Edit Display - Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

7.5.4 Edit Display - Graph . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

7.5.5 Display Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

7.5.6 Clear Graph . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

7.6 System Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

7.6.1 Unit Menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

7.6.2 Parameter Menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

7.6.2.1 Time. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

7.6.2.2 Save Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

7.6.2.3 Load Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .85

7.6.2.4 Reset Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .85

7.6.2.5 Screen Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

7.6.3 Disk Menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

7.6.3.1 Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

7.6.3.2 Record/Stop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

7.6.3.3 Record N . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

7.6.3.4 Format Disk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

7.6.3.5 Run Application. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

7.6.4 Communications Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

7.6.4.1 Serial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

7.6.4.2 IEEE-488 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

7.6.4.3 Printer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

7.6.4.4 Analog Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .91

7.6.4.4.1 Parameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

7.6.4.4.2 Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

7.6.4.4.3 Offset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

7.6.4.4.4 Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

7.6.4.4.5 Cal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

7.6.5 System Calibration Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

7.6.5.1 Set External . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94

7.6.5.2 Set Internal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

7.6.5.3 Calibrate Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .95

7.6.5.4 Security Lock-out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

7.6.5.5 Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

8 Communications Interface. . . . . . . . . . . . . . . . . . . . 99

8.1 Serial Communications . . . . . . . . . . . . . . . . . . . . . . . 99

8.1.1 Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

8.1.2 Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

8.1.3 Serial Communication Example Program. . . . . . . . . . . . . . . . . . . 100

8.2 IEEE-488 Communications . . . . . . . . . . . . . . . . . . . . 101

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8.2.1 Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

8.2.2 IEEE-488 Interface Functions . . . . . . . . . . . . . . . . . . . . . . . . . 101

8.2.2.1 Local Lockout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

8.2.2.2 Trigger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

8.2.2.3 Serial or Parallel Poll . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

8.2.2.4 Device Clear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

8.2.3 IEEE-488 Communication Example Program . . . . . . . . . . . . . . . . 102

8.3 Digital Interface Commands . . . . . . . . . . . . . . . . . . . . 103

9 Calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . 109

9.1 Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109

9.2 Resistance Ratio Calibration . . . . . . . . . . . . . . . . . . . . 110

9.3 Reference Resistor Calibration. . . . . . . . . . . . . . . . . . . 110

10 2575 Scanner (optional). . . . . . . . . . . . . . . . . . . . . 113

10.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

10.2 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

10.3 Quick Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114

10.3.1 Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114

10.3.1.1 Resistance Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114

10.3.1.2 Control Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114

10.3.1.3 Resistance Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115

10.3.2 Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

10.4 Parts and Controls . . . . . . . . . . . . . . . . . . . . . . . . . 116

10.5 Scanner Operation . . . . . . . . . . . . . . . . . . . . . . . . . 119

10.5.1 Soft-key Menus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119

10.5.2 Channel Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119

10.5.2.1 Scanner Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

10.5.2.2 Scanner Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

10.5.3 Probe Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122

10.5.3.1 Select Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122

10.5.4 Digital Interface Commands. . . . . . . . . . . . . . . . . . . . . . . . . . 123

11 2590 Scanner (optional) . . . . . . . . . . . . . . . . . . . . 125

11.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125

11.2 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . 125

11.2.1 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125

11.3 Quick Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

11.3.1 Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

11.3.1.1 Resistance Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

11.3.1.2 Control Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

11.3.1.3 Resistance Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

11.3.2 Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128

11.4 Parts and Controls . . . . . . . . . . . . . . . . . . . . . . . . . 128

11.5 Scanner Operation . . . . . . . . . . . . . . . . . . . . . . . . . 129

11.5.1 Channel Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

11.5.1.1 Scanner Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

iv

11.5.1.2 Scanner Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

11.5.2 Probe Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132

11.5.2.1 Select Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132

11.5.2.2 Standby Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133

11.5.3 Digital Interface Commands. . . . . . . . . . . . . . . . . . . . . . . . . . 133

12 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . 135

13 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . 137

13.1 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . 137

13.2 CE Comments (1590 Only) . . . . . . . . . . . . . . . . . . . . 140

13.2.1 EMC Directive. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140

13.2.1.1 Immunity Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141

13.2.1.2 Emission Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141

13.2.2 Low Voltage Directive (Safety) . . . . . . . . . . . . . . . . . . . . . . . . 141

v

Figures

Figure 1 Simplified Schematic Diagram of the Measurement Circuit . . . . . . . 6

Figure 2 Measurement Processing Operations . . . . . . . . . . . . . . . . . . . 7

Figure 3 1575/1590 Super-Thermometer Display . . . . . . . . . . . . . . . . . 24

Figure 4 Menu Tree . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Figure 5 Sample Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Figure 6 Smoothing Effect of the Digital Filter . . . . . . . . . . . . . . . . . . 41

Figure 7 Effect of Automatic Reset on Filtered Measurements . . . . . . . . . . 42

Figure 8 Example Calibration Report . . . . . . . . . . . . . . . . . . . . . . . 72

Figure 9 Example Calibration Table Page . . . . . . . . . . . . . . . . . . . . . 73

Figure 10 Data Type Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Figure 11 Graph Type Display . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

Figure 12 Example of Data Recorded to Disk or Output Via the Digital Interface . 86

Figure 13 Serial Cable Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

Figure 14 Scanner Output Connection. . . . . . . . . . . . . . . . . . . . . . . 114

Figure 15 1575 to 2575 Control Cable Connection . . . . . . . . . . . . . . . . 115

Figure 16 Probe Input Connection . . . . . . . . . . . . . . . . . . . . . . . . . 116

Figure 17 2575 Scanner Front Panel. . . . . . . . . . . . . . . . . . . . . . . . 117

Figure 18 Menu Tree of the 1575 (2575 Scanner Attached) . . . . . . . . . . . 118

Figure 19 2590 to 1590 Front Panel Connections . . . . . . . . . . . . . . . . . 126

Figure 20 2590 To 1590 Control Cable Connection . . . . . . . . . . . . . . . 127

Figure 21 2590 Scanner Front Panel. . . . . . . . . . . . . . . . . . . . . . . . 128

vi

Tables

Table1 International Electrical Symbols . . . . . . . . . . . . . . . . . . . . . 1

Table 2 ITS-90 Subranges and Coefficients . . . . . . . . . . . . . . . . . . . 48

Table 3 DIN-43760/IEC-751/ASTM E1137 Callendar-Van Dusen Coefficients. 49

Table 4 Reference Resistor Selection. . . . . . . . . . . . . . . . . . . . . . . 50

Table 5 ITS-90 Calibration Points . . . . . . . . . . . . . . . . . . . . . . . . 54

Table 6 Fixed-point Calibration Setup . . . . . . . . . . . . . . . . . . . . . . 56

Table 7 Manual Comparison Setup . . . . . . . . . . . . . . . . . . . . . . . . 56

Table 8 Automatic Sequencing Calibration Setup . . . . . . . . . . . . . . . . 57

Table 9 SPRT Resistance Comparison Calibration Setup . . . . . . . . . . . . 58

Table 10 Units of Measure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

Table 11 Interface Commands . . . . . . . . . . . . . . . . . . . . . . . . . . 105

Table 12 Interface Commands continued. . . . . . . . . . . . . . . . . . . . . 106

Table 13 Interface Commands continued. . . . . . . . . . . . . . . . . . . . . 107

Table 14 Interface Commands continued. . . . . . . . . . . . . . . . . . . . . 108

Table 15 Standard Resistors Used for Calibration of the Reference Resistors . . 109
Table 16 Standard Resistors Used for Calibration of the Ratio Measurement . . 109

Table 17 2575 Interface Commands . . . . . . . . . . . . . . . . . . . . . . . 123

Table 18 2590 Interface Commands . . . . . . . . . . . . . . . . . . . . . . . 133

vii

1 Before You Start

1.1 Symbols Used

Table 1 lists the symbols that may be used on the instrument or in this manual
and the meaning of each symbol.

Tabl e1 International Electrical Symbols

Symbol Description

AC (Alternating Current)

AC-DC

Battery

Complies with European Union Directives

1 Before You Start

Symbols Used

DC (Direct Current)

Double Insulated

Electric Shock

Fuse

PE Ground

Hot Surface (Burn Hazard)

Read the User’s Manual (Important Information)

Off

On

1

1575/1590 Thermometer Readout

User’s Guide

Symbol Description

Canadian Standards Association

OVERVOLTAGE (Installation) CATEGORY II, Pollution Degree 2 per IEC1010-1 re
fers to the level of Impulse Withstand Voltage protection provided. Equipment of
OVERVOLTAGE CATEGORY II is energy-consuming equipment to be supplied from
the fixed installation. Examples include household, office, and laboratory appliances.

C-TIC Australian EMC mark

The European Waste Electrical and Electronic Equipment (WEEE) Directive
(2002/96/EC) mark.

1.2 Safety Information

Use this instrument only as specified in this manual. Otherwise, the protection
provided by the instrument may be impaired. Refer to the safety information in
Sections 1.2.1 and 1.2.2.

The following definitions apply to the terms “Warning” and “Caution”.

• “WARNING” identifies conditions and actions that may pose hazards to

the user.

• “CAUTION” identifies conditions and actions that may damage the in-

strument being used.

1.2.1 WARNINGS

•

DO NOT use this unit in environments other than those listed in the
User’s Guide.

•

Follow all safety guidelines listed in the User’s Guide.

•

Calibration equipment should only be used by trained personnel.

•

This instrument can measure extreme temperatures. Precautions must be
taken to prevent personal injury or damage to objects. Probes may be ex
tremely hot or cold. Cautiously handle probes to prevent personal injury.
Carefully place probes on a heat/cold resistant surface or rack until they
reach room temperature.

•

DO NOT operate near flammable materials.

•

Use only a grounded AC mains supply of the appropriate voltage to
power the instrument.

•

DO NOT connect an AC mains supply that does not match the voltage
setting on the back of the unit.

•

DO NOT use this instrument in combination with any probe ( PRT,
thermistor, or thermocouple) to measure the temperature or resistance of
any device where the probe might come in contact with a conductor that

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2

1 Before You Start

Authorized Service Centers

is electrically energized. Severe electric shock, personal injury, or death
may occur.

1.2.2
CAUTIONS

If the instrument is dropped, struck, or handled in a way that causes inter

•

nal or external physical damage, immediately unplug the instrument, dis
continue use, and contact a Hart Scientific Authorized Service Center for
repair. Do not attempt to disassemble or repair the instrument, batteries,
or AC adapter. Refer repairs or replacement components to a Hart Scien
tific Authorized Service Center.

The instrument and thermometer probes are sensitive and can be easily

•

damaged. Always handle these devices with care. DO NOT allow them to
be dropped, struck, stressed, or overheated.

Probes are fragile devices which can be damaged by mechanical shock,

•

overheating, and absorption of moisture or fluids in the wires or hub.
Damage may not be visibly apparent but nevertheless can cause drift, in
stability, and loss of accuracy. Observe the following precautions:

• DO NOT allow probes to be dropped, struck, bent, or stressed.

• DO NOT overheat probes beyond their recommended temperature range.

• DO NOT allow any part of the probe other than the sheath to be im-

mersed in fluid.

• DO NOT allow the probe hub or wires to be exposed to excessive temper-

atures.

• Keep the probe wires clean and away from fluids.

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1.3 Authorized Service Centers

Please contact one of the following authorized Service Centers to coordinate
service on your Hart product:

Fluke Corporation, Hart Scientific Division

799 E. Utah Valley Drive

American Fork, UT 84003-9775

USA

Phone: [phone]

Telefax: +1.801.763.1010

E-mail: [e-mail]

Fluke Nederland B.V.

Customer Support Services

3

1575/1590 Thermometer Readout

User’s Guide

Science Park Eindhoven 5108

5692 EC Son

NETHERLANDS

Phone: [phone]

Telefax: [phone]

E-mail: [e-mail]

Fluke Int'l Corporation

Service Center - Instrimpex

Room 2301 Sciteck Tower

22 Jianguomenwai Dajie

Chao Yang District

Beijing 100004, PRC

CHINA

Phone: [phone]

Telefax: [phone]

E-mail: [e-mail]

Fluke South East Asia Pte Ltd.

Fluke ASEAN Regional Office

Service Center

60 Alexandra Terrace #03-16

The Comtech (Lobby D)

118502

SINGAPORE

Phone: [phone]

Telefax: [phone]

E-mail: [e-mail]

When contacting these Service Centers for support, please have the following
information available:

•

Model Number

•

Serial Number

•

Voltage

•

Complete description of the problem

4

2 Introduction

2.1 General Description

The 1575 “Super-Thermometer” and 1590 “Super-Thermometer II” are two of
the most accurate resistance and temperature readout instruments available. The
1575 can deliver resistance measurements with up to 4 ppm accuracy while the
1590 can achieve 1 ppm accuracy. In terms of temperature, 1 ppm is equivalent
to 0.00025°C with an SPRT at 0°C. When using the 1590 with a stan
dards-quality thermistor it’s possible to achieve measurements as accurate as

0.000125°C.

In addition to accuracy, the 1575 or 1590 has a variety of features and functions
that make it an indispensable tool in a precision temperature calibration labora

tory. With a wide input range of 0 to 500kΩ it can be used with just about any
type of resistance sensor including RTDs, PRTs, SPRTs, HTPRTs, and thermis
tors. The driving current is programmable to best suit the sensor. Resistance to
temperature calculations are performed automatically using any of a variety of
algorithms including the International Temperature Scale of 1990 (ITS-90),
IPTS-68, Callendar-Van Dusen, Steinhart-Hart and polynomial equations. The
1575/1590 can even calculate ITS-90 coefficients and generate a report based
on resistance and temperature measurements.

The 1575/1590 features an LCD graphics display that shows in a clear and
easy-to-read manner a variety of information such as present and past measure­ments, statistical results, and instrument settings. Measurements can be viewed
in numeric and graphic plot form. The display is easily configured by the user
for various applications. Contrast, brightness, and colors (1590 only) can be ad­justed. Even the tilt of the display on the 1590 can be set as desired. Operation
of the 1575/1590 is made simple and convenient with the use of soft-keys.
These are buttons having associated labels on the display. The functions of the
soft-keys can change between various contexts.

The 1575/1590 features exclusive gold-plated patented DWF connectors (U.S.
Patent No. 5,965,625) that are specially designed for this product. Operated
with a quick, easy push, the patented DWF connector accepts bare wires, spade
terminals, and banana plugs.

The 1575/1590 is able to communicate with computer systems through a vari
ety of interfaces. RS-232, IEEE-488, and parallel printer interfaces are all built
in. The convenient 31/2" disk drive allows temporary or permanent storage of
measurement data, probe coefficients, and instrument settings.

2 Introduction

General Description

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2.2 Theory of Operation

The 1575 “Super-Thermometer” and 1590 “Super-Thermometer II” require a
unique electronic design to achieve the necessary accuracy while meeting size,
weight, cost, and speed constraints. This section explains the measurement

5

1575/1590 Thermometer Readout

User’s Guide

technique used by these instruments and discusses issues related to
performance.

2.2.1 Measurement Technique

Fundamentally, the 1575/1590 measures the resistance ratio between two resis
tors by comparing their voltages when equal currents are applied. The simpli

­fied schematic in Figure 1 shows the basic components of the measurement
circuitry. These include the current source, sensor, reference resistor, relay
switch, amplifier, analog-to-digital converter (ADC), and central processing
unit (CPU). The reference resistor and sensor are connected in series and the
current flows through both simultaneously. The current produces a voltage on
each that is proportional to their respective resistances. The voltages are mea
sured with the amplifier and ADC. Since only one of the voltages can be mea

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sured at a time, the relay must be used to switch between them.

SENSOR

CURRENT

SOURCE

REFERENCE

Figure 1 Simplified Schematic Diagram of the Measurement Circuit

AMPLIFIERSWITCH

CONVERTER CPU

The voltage on each resistor is measured twice: once with the current in one di
rection and again with the current in the opposite direction. Subtracting the two
voltage measurements eliminates offset voltages (including those arising from
thermoelectric EMF) since they are constant. In summary, one ratio measure

-

ment requires four voltage samples:

1. Sensor, forward current (V

2. Sensor, reverse current (V

3. Reference, forward current (V

4. Reference, reverse current (V

X2

X1

)

)

)

R1

)

R2

The voltage samples are subtracted and divided to produce a ratio of sensor re
sistance to reference resistance:

-

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-

VV

−

XX

12

r

=

VVRR

RRXR

6

=

−

12

2 Introduction

Theory of Operation

Using this approach, errors from driving current imprecision, voltage offsets,
and amplifier and ADC inaccuracies are avoided because these all affect the
voltage samples equally.

Each voltage sample requires 0.5s. It takes 0.15s to set the current and relay
and allow time for the voltages to settle and 0.35s for the ADC to make a mea
surement and send it to the CPU. Since four samples are required, the entire ra
tio measurement takes two seconds.

Depending on how the measurement timing is set up, more than one raw ratio
sample may be integrated into one raw measurement. Digital filtering is also
applied to reduce noise in the measurements. The CPU then calculates the re

­sistance of the sensor by multiplying the measured resistance ratio by the
known resistance of the reference resistor. Temperature is calculated from resis
tance using one of the built-in conversion algorithms. Finally, statistical values
are recalculated to incorporate the latest measurement. Figure 2 below shows
this sequence of operations.

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-

Voltage

Samples

Voltage

Samples

Figure 2 Measurement Processing Operations

Raw

Ratio

Raw

Ratio

Integration

SPRTs and PRTs generally require temperature to be calculated according to
the International Temperature Scale of 1990 (ITS-90) by applying coefficients
unique to the SPRT or PRT. The 1575/1590 does these calculations automati
cally. The sensor coefficients are entered into the 1575/1590 by the user and
stored in non-volatile memory. Temperature is calculated in any of a variety of
units including degrees Celsius (°C), degrees Fahrenheit (°F), or Kelvin (K).
Once the temperature reading is obtained it is sent to the display, stored in
memory, and, if necessary, written to disk or any of the output ports.

2.2.2 Performance Issues

Measurement of temperature with uncertainty approaching 0.001°C or better
can be a significant challenge. Various sources of error inherent in resistance
thermometry make it difficult to achieve this level of accuracy. For instance,
lead resistance in some cases can cause errors of several tenths of a degree.
Problems also arise from sources such as thermoelectric EMF, reactance, and
leakage. The accuracy the 1575/1590 achieves is only possible because these
effects have been carefully studied and dealt with. The design of this instru
ment reduces or eliminates most of the errors that often plague resistance and

Digital

Filter

Resistance Temperature Display

DisplayStatistics

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7

1575/1590 Thermometer Readout

User’s Guide

temperature measurements. It also offers other advantages that contribute to the
value of this instrument. Consider the following issues.

2.2.2.1 Lead Resistance

Measurements using an electrical sensor can be affected by the resistance in the
connecting wires or leads. Resistance also exists in the patented DWF connec
tors and the junction between the wires and patented DWF connectors. In com
monly used two or three-wire measurement circuits these resistances and their
variability causes errors of 0.1 to 1.0°C.

The 1575/1590 uses a four-wire circuit that completely eliminates the effects of
lead resistance. In this scheme, often referred to as a Kelvin circuit, the sensor
is driven with current from one set of wires and the resulting EMF is sensed
with a different set of wires. The signal is passed to an amplifier with a very
high input impedance that draws negligible current from the sensor. As a result,
no measurable voltage develops along the EMF sensing wires. The 1575/1590
will accurately measure the resistance of sensors even in the presence of lead

resistance that can be as high as 10Ω.

2.2.2.2 Thermoelectric EMF

A resistance sensor such as a PRT contains several junctions between wires of
different metals. These act like thermocouples generating small electric poten­tials called thermoelectric EMFs. Unless rejected in some way, the thermoelec­tric EMFs can interfere with the sensor EMF and degrade the accuracy of the
measurement. There are three different techniques that can be used to cancel
thermoelectric EMF.

Some resistance bridges apply AC driving current and use sensing circuits that
detect only the AC signal, rejecting the DC EMFs. This technique is very effec
tive at eliminating thermoelectric EMF errors but can lead to other errors.
Reactance, leakage, and eddy currents become much more significant with AC.

A different technique sometimes used in DMMs is to periodically switch off
current to the sensor and measure the thermoelectric EMF directly. The prob
lem with this is it leads to self-heating errors as the sensor warms and cools
from the varying current.

The 1575/1590 uses a third technique. Two separate measurements are made
and the driving current is simply reversed for the second measurement. Ther
moelectric EMF causes errors that are opposite in the two measurements. In es
sence, averaging the two measurements cancels the errors. This technique is
very effective at eliminating errors from thermoelectric EMF while avoiding
the AC related errors and self-heating problems of the other methods. In fact,
it’s so effective in the 1575/1590 that the instrument is able to achieve an un
certainty of 0.00025°C or better with no observable error caused by thermo
electric EMF.

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-

8

2.2.2.3 Reactance

The use of AC driving current can cause errors in resistance thermometry be
cause sensors often exhibit significant inductance and capacitance. The
1575/1590 uses DC circuitry that is much less susceptible to these effects. It al
lows plenty of time for currents and voltages to settle before it begins a sample.
If necessary, the delay time can be increased even further to ensure accuracy.
The 1575/1590 is well suited for any type and quality of resistance sensor.

2.2.2.4 Leakage

Resistance sensors can be susceptible to electrical leakage through the insula
tion material surrounding the lead wires and sensing element. Leakage is often
significant at low temperatures where the insulation absorbs moisture from the
air or at high temperatures where the electrical conductivity of the insulating
material is relatively high. Leakage and some other effects, such as dielectric
absorption and eddy currents, are much more significant with AC than with
DC. By operating with DC driving current the 1575/1590 can achieve excellent
accuracy with a large variety of sensors and over a wide range of conditions.

2.2.2.5 Self-heating

Another source of trouble in resistance thermometry is self-heating. This re­sults from power being dissipated in the sensor by the driving current. It causes
the temperature of the sensor to be higher than it should be. The 1575/1590 is
able to achieve full accuracy with small currents that minimize self-heating (1

mA for PRTs and 10 μA for thermistors). The current can be set within a wide
range and with excellent resolution. Being able to set the current to precise ar­bitrary values allows self-heating errors to be controlled, measured, and
canceled.

2 Introduction

Theory of Operation

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2.2.2.6 Component Drift

The accuracy of a typical resistance measuring instrument is seriously limited
by the stability, or lack thereof, of its electrical components. The design of the
1575/1590 eliminates sensitivity to variations of the components due to aging
or temperature. This is because, in effect, the instrument recalibrates itself dur
ing every measurement. Drift of the driving current, amplifier bias current, am
plifier offset voltage, amplifier gain, ADC offset, and ADC scale have no effect
on the measurement. The accuracy to which the instrument measures resistance
is only affected by the drift of one component-the reference resistor. The four
resistors built into the 1575/1590 are high-quality, hermetically sealed, low
temperature coefficient, metal film resistors that are temperature controlled for
excellent stability. Even better stability can be achieved if external standard re
sistors are used and they are immersed in a precisely-controlled oil bath.

2.2.2.7 Noise and Resolution

There will always be electrical noise in any measurement circuit; it’s unavoid
able. Excessive noise causes measurements to appear to vary randomly over

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9

1575/1590 Thermometer Readout

User’s Guide

time. This makes it impossible to detect small real changes in the parameter be
ing measured. In effect, it limits the resolution of the measuring instrument.

Electrical noise in the 1575/1590 comes from a variety of sources. A small
amount of noise is generated by the resistors and semiconductor devices in the
measurement circuitry. Some noise (quantization noise) results from the limited
resolution of the ADC. Electrical interference or EMI from internal or external
sources can also be a source of noise. Although it is impossible to completely
eliminate all noise, some steps can be and are taken to reduce it. Components
were selected for their low-noise qualities. The ADC was chosen, in part, for its
excellent resolution (24 bits). Shielding is used to block EMI from reaching the
sensitive circuits. To further reduce noise the 1575/1590 uses filtering and EMI
suppression devices throughout the circuit. (Since the 1575/1590 operates with
DC driving current, it can effectively reject interference coming from the 50/60
Hz. mains supply. AC instruments are more susceptible to this interference.) Fi
nally, the CPU applies digital filtering to remove much of the remaining noise.
The end result is the capability of making measurements with effective resolu
tion as good as 0.25 PPM.

One drawback of digital filtering is that it might make the instrument react
more slowly to changes in the resistance or temperature being measured. The
1575/1590 allows the user to adjust the digital filter to achieve the right balance
between resolution and response.

2.2.2.8 Nonlinearity

Having taken care of all the other sources of error explained above, all that’s
left is nonlinearity. Consider nonlinearity to be curvature in the graph of the re­lationship between the actual resistance ratio and the resistance ratio measured
by the 1575/1590. It is a result of imperfections in the analog-to-digital con­verter and also, to a smaller degree, the power supply and amplifier.

To minimize nonlinearity in the 1575/1590 three steps have been taken. First,
the best available components have been selected. For instance, the ADC is a
dual-slope integrating type that has linearity that’s at least ten times better than
other precision integrating or sigma-delta ADCs. Second, the measurement
technique that’s used inherently rejects much of the nonlinearity. Because sam
ples of opposite polarity are subtracted, zeroth-order errors (offsets), second-or
der errors, and all higher even-order components of the nonlinearity are
canceled. What’s left are third-order and higher odd-order components that di
minish greatly in magnitude the higher the order. The third step is to mathemat
ically correct for the third-order nonlinearity. This is the purpose of the “ADC”
calibration parameter. This parameter is adjusted during calibration to achieve
the best possible linearity.

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10

2.2.2.9 Measurement Speed

The measurement scheme used by the 1575/1590 offers other advantages in ad
dition to accuracy. One of these is speed. The 1575/1590 is capable of complet
ing a new measurement in only two seconds. Even if multiple sensors are being
measured in turn, the measurement time per sensor is still only two seconds.

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-

Compare this to a typical resistance bridge that takes 30 to 60 seconds to make
the first measurement after a sensor is connected. The speed of the 1575/1590
gives it the advantage of allowing greater efficiency as well as better accuracy
during a batch calibration process involving a large number of sensors. Inte
grating the 1575/1590 with the 2575/2590 multiplexer enhances its capability
even more, giving it 10 input channels (or up to 50 for the 1590 with multiple
2590s). The measurement speed of the 1575/1590 makes other applications
possible such as tracking fast-changing temperatures, measuring temperature
differences, or evaluating thermal response times.

2.2.2.10 Solid-State Design

Unlike a bridge that requires a large, heavy precision ratio transformer and doz
ens of relays, the 1575/1590 uses semiconductor circuits and only a few relays
to switch between resistors. This gives it better reliability, smaller size, lighter
weight, and lower cost. By keeping the size and cost of the measuring circuit
small, more space and expense can be dedicated to other important features
such as intelligent system control electronics, a convenient user interface, a
graphic display, and a built-in disk drive, all contributing to making the
1575/1590 so versatile and useful.

2 Introduction

Theory of Operation

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11

3 Specifications and Environmental Conditions

3 Specifications and Environmental

Conditions

3.1 Specifications

Specification 1575 1590

Resistance Measurement Range

Resistance Ratio Accuracy

Ω

0to.25

0.25 to 4Ωinput (1Ωrefr, 10 mA)

2.5to40

0to25

25 to 400Ωinput (100Ωrefr, 1 mA)

400 to 1000

0to2.5k

2.5to40kΩinput (10 kΩrefr, 0.01 mA)

40 to 100 k

100 to 500 k

Resistance Accuracy

0to.25

0.25 to 4Ωinput (1Ωrefr, 10 mA)

2.5to40

0to25

25 to 400Ωinput (100Ωrefr, 1 mA)

400 to 1000

0to2.5k

2.5to40kΩinput (10 kΩrefr, 0.01 mA)

40 to 100 k

100 to 500 k

Typical Temperature Accuracy, External Reference

0.25

2.5

25

100

10 k

Typical Temperature Accuracy, Internal Reference

0.25

2.5

25

input (1Ωrefr, 10 mA) 0.00001

Ω

input (10Ωrefr, 3 mA)

Ω

input (100Ωrefr, 1 mA) 0.0001

Ω

input (100Ωrefr, 0.1 mA)

Ω

input (10 kΩrefr, 0.01 mA) 0.025

Ω

input (10 kΩrefr, 0.005 mA)

Ω

input (10 kΩrefr, 0.002 mA)

Ω

input (1Ωrefr, 10 mA) 0.000025

Ω

input 10Ωrefr, 3 mA)

Ω

input (100Ωrefr, 1 mA) 0.0002

Ω

input (100Ωrefr, 0.1 mA)

Ω

input (10 kΩrefr, 0.01 mA) 0.05

Ω

input (10 kΩrefr, 0.005 mA)

Ω

input (10 kΩrefr, 0.002 mA)

Ω

SPRT (0°C, 1Ωrefr, 10 mA)

Ω

SPRT (0°C, 10Ωrefr, 3 mA)

Ω

SPRT (0°C, 100Ωrefr, 1 mA)

Ω

SPRT (0°C, 100Ωrefr, 1 mA) 0.001°C 0.00025°C

Ω

thermistor (25°C, 10 kΩrefr, 0.01 mA)

Ω

SPRT (0°C, 1Ωrefr, 10 mA)

Ω

SPRT (0°C, 10Ωrefr, 3 mA)

Ω

SPRT (0°C, 100Ωrefr, 1 mA)

200 ppm 120 ppm

100 ppm 40 ppm

200 ppm 120 ppm

0.00025°C 0.00013°C

0 to 500 k

Ω

40 ppm 20 ppm

20 ppm 5 ppm

Ω

4 ppm 1 ppm

20 ppm 4 ppm

Ω

10 ppm 5 ppm

50 ppm 25 ppm

Ω

40 ppm 20 ppm

Ω

8 ppm 6 ppm

25 ppm 10 ppm

Ω

20 ppm 10 ppm

60 ppm 30 ppm

0.01°C 0.005°C

0.005°C 0.0013°C

0.001°C 0.00025°C

0.025°C 0.01°C

0.01°C 0.005°C

0.002°C 0.0015°C

Specifications

Ω

0.000005

0.000025

0.012

Ω

0.00001

0.00015

0.025

Ω

Ω

Ω

Ω

Ω

13

1575/1590 Thermometer Readout

User’s Guide

Specification 1575 1590

Ω

SPRT (0°C, 100Ωrefr, 1 mA) 0.002°C 0.0015°C

100

Ω

thermistor (25°C, 10 kΩrefr, 0.01 mA)

10 k

Typical RMS Measurement Noise No Filter 20 Second Filter

Ω

input (1Ωrefr, 10 mA)

0.25

Ω

input (10Ωrefr, 3 mA)

2.5

Ω

input (100Ωrefr, 1 mA)

25

Ω

input (100Ωrefr, 1 mA)

100

Ω

input (100Ωrefr, 1 mA)

400

Ω

input (10 kΩrefr, 0.01 mA)

10 k

Minimum Sample Period 2 seconds

Maximum Current

Ω

reference, 1Ωinput

1

Ω

reference, 10Ωinput

10

Ω

reference, 100Ωinput

100

Ω

reference, 10 kΩinput

10 k

Typical Current Accuracy 2% or 0.0002 mA

Power 100–125/200–250 VAC (user-switchable), 50-60

Specified Operating Temperature 20 to 27°C (68 to 81°F)

Operating Temperature Limits 10 to 40°C (50 to 104°F)

Storage Temperature –10 to 50°C (14 to 122°F)

Safety OVER VOLTAGE (Installation) CATEGORY 11,

Size 516 mm x 320 mm x 178 mm

Weight 16 kg (35 lb)

Notes:

•

Specifications stated in ppm are relative to the reading.

•

Accuracy specifications are applicable for a one-year calibration interval. In line with
normal prudent metrology practices, Hart recommends a short-cycle calibration interval
of six months for new units during the first year to ensure that all components are as
stable as expected.

•

Accuracy specifications do not include noise which is stated separately and depends on
the digital filter settings.

•

For measurements above 100kΩ the conversion time should be set to 4 seconds.

•

The specifications are applicable within the specified operating temperature range. Re
sistance accuracy is derated 10 ppm if using the 1 ohm resistor, 5 ppm if using the 10Ω
or 10 kΩ resistors, and 2 ppm if using the 100Ω resistor for every degree Celsius out
side the specified operating temperature range.

•

Temperature accuracy specifications do not include sensor errors or external resistor
uncertainty.

0.0005°C 0.00025°C

25 ppm 8 ppm

8 ppm 2.5 ppm

2.5 ppm 0.8 ppm

1 ppm 0.3 ppm

2.5 ppm 0.8 ppm

6 ppm 2 ppm

20 mA

15 mA

5 mA

0.1 mA

Hz, 1A max

Pollution Degree 2 per IEC1010-1

(20.3" W x 12.6" D x 7.0" H)

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14

3 Specifications and Environmental Conditions

3.2 Environmental Conditions

Environmental Conditions

Although the instrument has been designed for optimum durability and trou
ble-free operation, it must be handled with care. The instrument should not be
operated in an excessively dusty, dirty, or wet environment. Maintenance and
cleaning recommentdations can be found in the Maintenacne section of this
manual.

For full accuracy, operate the instrument in ambient temperatures between
20–27°C (68-81°F). Do not operate the instrument in an environment colder
than 10°C (50°F) or warmer than 40°C(104°F).

The instrument operates safely under the following conditions:

Temperature range: 10 to 40°C

•

Ambient relative humidity: 15 to 50%

•

Pressure: 75 to 106 kPa

•

Vibrations should be minimized

•

• Altitude less than 2,000 meters

3.3 Warranty

Fluke Corporation, Hart Scientific Division (Hart) warrants this product to be
free from defects in material and workmanship under normal use and service
for a period as stated in our current product catalog from the date of shipment.
This warranty extends only to the original purchaser and shall not apply to any
product which, in Hart’s sole opinion, has been subject to misuse, alteration,
abuse or abnormal conditions of operation or handling.

Software is warranted to operate in accordance with its programmed instruc
tions on appropriate Hart products. It is not warranted to be error free.

Hart’s obligation under this warranty is limited to repair or replacement of a
product which is returned to Hart within the warranty period and is determined,
upon examination by Hart, to be defective. If Hart determines that the defect or
malfunction has been caused by misuse, alteration, abuse or abnormal condi
tions or operation or handling, Hart will repair the product and bill the pur
chaser for the reasonable cost of repair.

To exercise this warranty, the purchaser must forward the product after calling
or writing to an Authorized Service Center (see Section 1.3 on page 3) for au
thorization. The Service Centers assume NO risk for in-transit damage.

THE FOREGOING WARRANTY IS PURCHASER’S SOLE AND EXCLU
SIVE REMEDY AND IS IN LIEU OF ALL OTHER WARRANTIES, EX
PRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY
IMPLIED WARRANTY OR MERCHANTABILITY, OR FITNESS FOR ANY
PARTICULAR PURPOSE OR USE. HART SHALL NOT BE LIABLE FOR
ANY SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL DAM
AGES OR LOSS WHETHER IN CONTRACT, TORT, OR OTHERWISE.

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15

4 Quick Start

4 Quick Start

This section briefly explains the basics of setting up and operating your 1575 or
1590 thermometer readout.

4.1 Unpacking

Carefully unpack the 1575 or 1590 thermometer readout and inspect it to make
sure all components are present and in satisfactory condition. Verify that the
following items are present:

1575 or 1590 Thermometer Readout

•

Serial Cable

•

Manual

•

Report of Calibration

•

• Calibration Label

If all items are not present, call a Hart Scientific Authorized Service Center.

4.2 Learn About the Features and Components

Unpacking

Familiarize yourself with the features and components of the 1575 or 1590 by
reading Section 5.

4.3 2575/2590 Scanner Setup

If a 2575 or 2590 scanner was purchased, refer to Section 10, 2575 Scanner or
Section 11, 2590 Scanner concerning specifics to each scanner.

4.4 Power Source

The 1575/1590 is normally configured to use 100–125 VAC, 50-60Hz. It may
optionally be switched to use 200–250 VAC, 50-60Hz. The switch on the back
of the instrument is used for switching the voltage. Make sure the voltage
switch is always set correctly!

4.5 Probe Connection

Your SPRT or thermistor probe connects to the 1575/1590 using the patented
DWF connector posts of Input 1. The input accepts a four-wire probe. The C1
and C2 patented DWF connectors source current to the probe and P1 and P2
measure the voltage on the probe. A resistor used for a reference should be
connected to Input 2 in the same fashion.

17

1575/1590 Thermometer Readout

User’s Guide

There are also ‘Guard’ patented DWF connectors for each channel and a ‘Chas
sis’ patented DWF connector that can be used for attaching guard wires and for
grounding. Probes that have shielded cables will be less susceptible to electro
magnetic interference (EMI). Best results may be obtained if the guard wire is
attached to the ‘Guard’ patented DWF connector, the ‘Chassis’ patented DWF
connector, or both. This depends on environmental conditions and placement of
the probe. If the probe has no shield or guard try simply connecting a wire be
tween the ‘Guard’ and ‘Chassis’ patented DWF connectors. Experiment with
each scheme to find what works best in your application.

The probe patented DWF connectors are operated by simply pressing on them.
Pressing on a patented DWF connector opens it allowing you to insert wires
with or without spade terminals. When the patented DWF connector is released
it will clamp down on the wire. Banana plugs can also be inserted into the hole
in the top of the patented DWF connectors.

4.6 Switch the Power On

Power is switched on and off with the power button located on the front panel,
lower left corner. The instrument will take one or two minutes to power up, ini­tialize itself, and begin normal operation. During initialization the display re­mains dark.

4.7 Measure Temperature

To make temperature measurements using your probe you must set up the
following:

1.

Select the channel to which your probe is connected. To do this enter
the CHANNEL MENU and press the INPUT 1 soft-key if the probe is
connected to Input 1 or press the INPUT 2 soft-key if it is connected to
the Input 2 (Section 7.1). If you are using the 2575 or 2590 Scanner,
press the appropriate channel button on the 2575/2590 front panel or use
the SELECT CHANNEL soft-key to select the channel as explained in
the scanner’s manual. Use the RETURN soft-key to exit the menu.

2.

Set up the reference for the probe. To do this enter the PROBE
MENU, select EDIT PROBE (Section 7.4.3), and press Enter to select
the probe number. In the EDIT PROBE window, move the cursor down

to the REFERENCE selection using the U and D keys. Use the L and
R keys and Enter to select the appropriate reference for your probe
(Section 7.4.3.3). For example, a 25Ω SPRT may use the 100Ω refer

ence. Be sure to always press Enter after making any selection.

3.

Set the current for the probe. This is also done in the EDIT PROBE
function. Move the cursor to CURRENT using the U and D keys. Use

the numeric keys and Enter to enter the appropriate current for your par
ticular probe. Your probe specifications should state the required current.

For example, a 25Ω SPRT may use 1 mA.

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18

4 Quick Start

Measure Temperature

4.

Set the temperature conversion type. Move the cursor to the CON

-

VERSION selection. Use the L and R keys and Enter to select
ITS-90 or whatever conversion is appropriate for your probe (Section

7.4.3.2). Refer to the calibration report or specifications for your probe.
Most SPRTs and RTDs use the ITS-90.

5.

Enter the characterization coefficients for your probe. Use the nu
meric keys and Enter to enter each coefficient. The coefficients are deter

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­mined when the probe is calibrated. Refer to the calibration report or
specifications for your probe. When finished exit out to the main menu
using the RETURN soft-key or Exit.

6.

Begin sampling. If the 1575/1590 is not now sampling press the RUN
soft-key in the SAMPLE MENU to begin sampling (Section 7.2.1).

The 1575/1590 should now be able to measure temperature accurately. If de
sired, you can modify the filter settings in the SAMPLE MENU to minimize
noise (Section 7.2.4). You may change the units from °C to any other desired
units such as °F or K using the UNIT soft-key in the SYSTEM menu (Section

7.6.1). You can set up the display to show statistical data or graph measure­ments in the DISPLAY MENU (Section 7.5).

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19