_STP_470A-1974_1981.pdf

MANUAL ON THE USE OF THERMOCOUPLES IN TEMPERATURE MEASUREMENT Sponsored by ASTM Committee E-20 on Temperature Measurement and Subcommittee IV on Thermocouples AMERICAN SOCIETY FOR TESTING AND MATERIALS ASTM SPECIAL TECHNICAL PUBLICATION 470A 04-470010-40 lj AMERICAN SOCIETY FOR TESTING AND MATERIALS 1916 Race Street,Philadelphia,Pa.19103 Copyright by ASTM Intl(all rights reserved);Sun Nov 29 19:51:25 EST 2015Downloaded/printed byUniversity of Washington(University of Washington)pursuant to License Agreement.No further reproductions authorized.()BY AMERICAN SOCIETY FOR TESTING AND MATERIALS 1974 Library of Congress Catalog Card Number:73-90277 NOTE The Society is not resPonsible,as a body,for the statements and opinions advanced in this publication.Second Printing,February 1977 Third Printing,July 1979 Fourth Printing,February 1981 Copyright by ASTM Intl(all rights reserved);Sun Nov 29 19:51:25 EST 2015Downloaded/printed byUniversity of Washington(University of Washington)pursuant to License Agreement.No further reproductions authorized.Foreword The Manual on the Use of Thermocouples in Temperature Measure-ments was sponsored and compiled by Committee E-20 on Temperature Measurement and Subcommittee IV on Thermocouples of the American Society for Testing and Materials.The editorial work was co-ordinated by R.P.Benedict,Westinghouse Electric Corp.Copyright by ASTM Intl(all rights reserved);Sun Nov 29 19:51:25 EST 2015Downloaded/printed byUniversity of Washington(University of Washington)pursuant to License Agreement.No further reproductions authorized.Related ASTM Publications The Theory and Properties of Thermocouple Elements,STP 492(1971),$7.25(04-492000-40)Copyright by ASTM Intl(all rights reserved);Sun Nov 29 19:51:25 EST 2015Downloaded/printed byUniversity of Washington(University of Washington)pursuant to License Agreement.No further reproductions authorized.Contents Chapter Chapter Chapter Chapter 1-Introduction 2-Principles of Thermoelectric Thermometry 2.1 Historical Development of Basic Relations 2.1.1 Seebeck 2.1.2 Peltier 2.1.3 Thomson 2.1.4 Interim Summary 2.1.5 Kelvin Relations 2.1.60nsager Relations 2.2 Laws of Thermoelectric Circuits 2.2.1 Law of Homogeneous Metal 2.2.2 Law of Intermediate Metals 2.2.3 Law of Successive or Intermediate Temperature 2.3 Elementary Thermoelectric Circuits 2.4 Bibliography 2.4.1 Early Historical References 2.4.2 Recent References 2.5 Nomenclature 3-Thermocouple Materials 3.1 Common Thermocouple Types 3.1.1 General Application Data 3.1.2 Properties of Thermoelement Materials 3.2 Extension Wire 3.2.1 General Information 3.2.2 Sources of Error 3.3 Nonstandardized Thermocouple Types 3.3.1 Platinum Types 3.3.2 Iridium-Rhodium Types 3.3.3 Platinel Types 3.3.4 Nickel-Chromium Types 3.3.5 Nickel-Molybdenum Types 3.3.6 Tungsten-Rhenium Types 3.4 Compatibility Problems at High Temperature 3.5 References 4-Thermocouples Hardware and Fabrication 4.1 Sensing Element Assemblies 4.2 Nonceramic Insulation 4.3 Hard-Fired Ceramic Insulators 4.4 Protection Tubes 4.5 Circuit Connections 4.6 Complete Assemblies 4.7 Selection Guide for Protection Tubes 4.8 Bibliography 3 3 3 4 5 6 7 10 12 13 13 14 15 16 16 17 17 19 19 19 23 24 24 28 33 34 39 40 42 48 49 52 54 55 56 56 58 58 63 64 65 70 Copyright by ASTM Intl(all rights reserved);Sun Nov 29 19:51:25 EST 2015Downloaded/printed byUniversity of Washington(University of Washington)pursuant to License Agreement.No further reproductions authorized.vi CONTENTS Chapter 5-Sheathed,Compacted Ceramic-Insulated Thermocouples 5.1 General Considerations 5.2 Construction 5.3 Insulation 5.4 Wire 5.5 Sheath 5.6 Combinations of Sheath,Insulation,and Wire 5.7 Limitations of the Basic Material 5.8 Testing 5.9 Measuring Junction 5.10 Terminations 5.11 Installation of the Finished Thermocouple 5.12 Sheathed Thermocouple Applications 5.13 References 71 71 71 74 78 78 78 79 81 82 87 87 88 90 Chapter 6-Emf Measurements 6.1 General Considerations 6.2 Potentiometer Theory 6.3 Precision Potentiometry 6.3.1 Laboratory High Precision 6.3.2 Plant Precision 6.3.3 Portable Precision 6.4 Semiprecision Potentiometry 92 92 93 95 95 96 96 96 Chapter 7-Reference Junctions 7.1 General Considerations 7.2 Reference Junction Techniques 7.2.1 Fixed Reference Temperature 7.2.2 Electrical Compensation 7,2.3 Mechanical Reference Compensation 7.3 Sources of Error 7.3.1 Immersion Error 7.3.2 Galvanic Error 7.3.3 Wire Matching Error 7.4 References 98 98 98 99 101 103 103 103 103 104 104 Chapter 8-Calibration of Thermocouples 8.1 General Considerations 8.1.1 Temperature Scale 8.1.2 Working Standards 8.1.3 Annealing 8.1.4 Measurement of Emf 8.1.5 Homogeneity 8.1.6 General Calibration Methods 8.1.7 Calibration Uncertainties 8.2 Calibration Using Fixed Points 8.2.1 Freezing Points 8.2.2 Melting Points 8.3 Calibration Using Comparison Methods 8.3.1 Laboratory Furnaces 8.3.2 Stirred Liquid Baths 8.3.3 Fixed Installations 106 106 106 110 111 112 112 114 115 118 118 119 119 120 123 123 Copyri