ABSTRACT
Blackbody Cavity Pyrometer 948 Radiation Pyrometers (Infrared
Thermometers) 949 Line-of-Sight Measurement Techniques 950
Acoustic Pyrometer 950 TDLAS 950
Radiation Pyrometers (Infrared Thermometers) 952
2D Measurement Method 952 2D Surface Temperature Sensing
Techniques 952 2D Cross-Section Temperature Mapping
Techniques 954 3D Temperature Field Visualization System 957 Summary 960
Advantages 960 Disadvantages 961
Speci cation Forms 961 Abbreviations 964 Organizations 964
4.4 BIMETALLIC THERMOMETERS 965
Bimetallic Springs 966 Thermometers 966 Dial Orientation and Size 967 Advantages and Disadvantages 968 Speci cation Form 968 Standards Organizations 970 Bibliography 970
4.5 CALIBRATORS AND SIMULATORS 971
Introduction 972 Calibration Baths 973 Calibrators 973
Black Body Calibrators 973 Block Calibrator 973 Fluidized Sand Bath Calibrators 974 Ice Point™ Calibrators 974
Simulators 974 Conclusions 976 De nition 976 Abbreviations 976 Organization 976 Bibliography 976
4.6 CONES, CRAYONS, LABELS, PAINTS, AND PELLETS 977
Introduction 978 Color Indicators 978
Paints and Pellets 978 Crayons 979
Pyrometric Cones 980 Ceramic Industry Applications 981 Bar and Hole Indicators 982
Engine Testing 982 Bibliography 982
4.7 FILLED-BULB AND GLASS-STEM THERMOMETERS 983
Introduction 984 Glass-Stem Thermometers 984 Filled Thermal Systems 985 Bulbs, Wells, and Capillaries 987
Class I: Liquid-Filled Systems 988 Class II: Vapor-Filled Systems 988 Class III: Gas-Filled Systems 990 Class V: Mercury-Filled Systems 990
Ambient Temperature Compensation 990 Effects of Bulb Elevation 992 Barometric Errors 992 Conclusions 992 Speci cation Forms 993 De nition 996 Bibliography 996
4.8 INTEGRATED CIRCUITRY (IC), TRANSISTORS AND DIODES 997
Introduction 997 IC Temperature Sensors 998 Diode-Type Temperature Sensors 999 Speci cation Form 1000 De nitions 1002 Abbreviation 1002 Bibliography 1002
4.9 MISCELLANEOUS TEMPERATURE SENSORS 1003
Self-Measuring Devices 1004 Newer Measurement Methods 1004
Optical Switch 1004 Time-Domain Reectometry 1004 Acoustic Thermometer 1004 Carbon Resistors 1004 Special Resistors 1004 Capacitance Detection of Hot Spots 1005 Fluidic Sensors 1005 Johnson Noise Thermometer (JNT) 1005 Liquid Crystal Thermometers 1005 Paramagnetic Salt Thermometers 1006 Spectroscopic Measurement 1006 Thermography 1007 Fiber Bragg Grating (FBG) 1007
No Longer Marketed 1007 Suction Thermometers 1007 Pneumatic Thermometers 1008 Quartz Crystal Thermometry 1009
Speci cation Forms 1009 Abbreviations 1011 Bibliography 1011
4.10 OPTICAL FIBER THERMOMETERS (OFT) 1012
Introduction 1013 Phase Interference and Fiber
Deformation 1013 High Temperature Detection 1013 Infrared OFT Thermometry 1014
Fiber Characteristics 1014 Probe Design Variations 1015
Blackbody Type Sensors 1017 Fluoroscopic Sensors 1017 Conclusions 1018 Speci cation Form 1018 De nitions 1021 Abbreviations 1021 Bibliography 1021
4.11 RADIATION PYROMETERS: INFRARED (IR), TOTAL, AND OPTICAL 1022
Introduction 1023 Theory 1024
Targets 1025 Emittance and Emissivity 1025
Selection 1026 Pyrometer Designs 1028
Total Radiation 1028 Narrow-Band 1029 Ratio 1030 Optical Hand-Held Units 1030 Portable and Video Designs 1031 Automatic Pyrometers 1031 Disappearing Filament Design 1033
Detectors 1033 Thermal Detectors 1033 Photodetectors 1033
Installations 1034 New Designs 1035 Conclusions 1036 Advantages 1036 Disadvantages 1036 Speci cation Form 1036 De nitions 1038 Abbreviations 1039 Bibliography 1039
4.12 RESISTANCE TEMPERATURE DETECTORS (RTDs) 1040
Basics 1042 Detector Types 1042
Industrial Requirements 1043 Platinum RTDs 1043 Base-Metal RTDs 1044 Nickel-Iron (Balco™) 1044 Copper 1044
Measurement Methods 1045 Two-Wire RTDs 1045 Three-Wire RTDs 1046 Four-Wire RTDs 1046
Sensor Construction 1047 Thermowells 1047 Immersion Length 1048 Wire Color Codes 1049
Installation 1049 Transmitters 1050
Fixed Range 1050 Programmable 1050 Smart or Intelligent 1050 Wireless 1050
Conclusions 1050 Advantages 1051 Limitations 1051
Speci cation Forms 1051 De nitions 1054 Abbreviations 1054 Organizations 1054 Applicable ASTM Standards 1054
ASTM 1054 Bibliography 1054
4.13 TEMPERATURE SWITCHES AND THERMOSTATS 1055
Introduction 1056 Temperature Switches 1056
Terminology 1056 Electromechanical Designs 1056 Electronic Designs 1058 Installation 1058 Availability and Reliability 1059
Thermostats 1059 Electromechanical Designs 1059 Pneumatic Designs 1060 Design Features 1061 Electrical/Electronic Designs 1063 Intelligent Thermostats 1063
Speci cation Forms 1063 Abbreviations 1066 Organizations 1066 Bibliography 1066
4.14 THERMISTORS 1067
Introduction 1068 History 1068 Resistance-Temperature Characteristic 1069 Sensor Types 1070 Temperature Measurement 1071
Microammeter Readout 1071 Wheatstone Bridge 1071 Digital Readouts 1072
Combined With Resistors 1072 Self-Heating 1073 Applications 1073 Calibration and Testing 1073 Conclusions 1074 Speci cation Forms 1074 De nitions 1077 Abbreviations 1077 Bibliography 1077
4.15 THERMOCOUPLES 1078
Theory of Operation 1080 Interpreting the Generated Voltage 1080 Laws of Intermediate Temperatures and
Metals 1082 Cold Junction Compensation 1082 Multiplexing 1083 Hardware Compensation 1084
Measuring the EMF Generated 1084 Transmitter Location and Noise 1084
Thermocouple Types 1085 ISA Types J, S, and T 1086 ISA Types B, E, K, R, and N 1087 Thermocouple Construction and
Protection 1087 Measuring Junction Designs 1087 Extension Wires 1088 Sheath Materials 1088 Thermowells 1088 Surface Temperature Detectors 1089 Specialized Detectors 1090
Installation and Protection 1090 Multiple Thermocouples 1090 Thermocouple Burnout 1091 Protection against Noise 1092
Temperature Measurement Inside Reactors 1093 Application 1093 Thermocouple Selection 1093 Construction and Design 1093 Engineering Considerations 1094 Connection to Control System 1095
Calibration, Diagnostics, and Transmission 1095 Calibration 1095 Diagnostics 1095 Transmission 1095
Advantages and Limitations 1096 Thermocouple Tables 1096
Converting Millivoltage to Temperature 1103 Converting Temperature to Millivoltage 1104
Speci cation Forms 1104 Abbreviations 1107 Bibliography 1107
4.16 THERMOWELLS 1108
Introduction 1109 Protection Types 1110
Thermowells 1110 ASME Standards 1111 Protection Tubes 1112 Ceramic Protection Tubes 1113 Sheaths 1114 Wake Frequency Calculations 1115
Installation 1117 Immersion Depth 1118
Response Time 1119 Material Selection Guide 1119 Speci cation Form 1123 Standards 1124 Bibliography 1124
4.17 ULTRASONIC THERMOMETERS 1125
Introduction 1125 Gas Temperature 1125
Ranges and Applications 1126 Liquids and Solids 1126
Applications 1127 Conclusions 1128 Speci cation Form 1129 Bibliography 1130
SELECTION AND CONVERSION TABLES
Table 4.1a (Page 905): Conversion Formulas Table 4.1b (Page 907): Ranges and Accuracies Table 4.1c (Page 909): Selection Guidance for Different Applications Table 4.1d (Page 909): International Temperature Scale, Primary Points Figure 4.1a (Page 910): Ranges Given Graphically Table 4.1e (Pages 930): Conversion between Centigrade and Fahreheit
INTRODUCTION
Temperature quanti es the degree or intensity of heat present in a substance or object and as such it is a numerical measure of hot and cold. Temperature is expressed in different units. These include:
Celsius is a thermodynamic scale introduced by Andrew Celsius (1701-1744) and is also called Celsius. Until 1954 0°C was de ned as the freezing and 100°C was de ned as the boiling point of water. In 1954 the SI units were introduced resulting in a slight change, because both the degree Celsius and the Kelvin units were rede ned as precisely 1 part in 273.16 (approximately 0.00366) of the difference between absolute zero and the triple point of water. Additionally, the null point was rede ned as precisely 273.15 degrees Celsius (−273.15°C = 0 K and 0°C = 273.15 K).
