Revision of the International Practical Temperature Scale requires that there be changes for all accurately tabulated therrnophysical values. Revised reference data for thermocouples have been generated in a cooperative program between groups of the National Bureau of Standards in Boulder and Gaithersburg. This Monograph contains tables, analytic expressions, various approximations, and explanatory text. Only the standard letter-designated thermocouples are described: noble metal Types S, R, and B and base metal Types E, J, K, and T. Their appropriate "single-leg" or thermo element versus Pt-67 values are also included. The new reference data reflect not only revisions in the temperature scale, but also slight changes in the materials themselves and improvements in data fitting methods. The temperature ranges vary for different types, from a low of —270 °C for Type E to a high of 1820 °C for Type B. The main functions and tables are given in terms of Celsius degrees and microvolts. Tables in the appendices represent the data with less precision, in millivolts, and in degrees Fahrenheit as well as Celsius. Approximate quadratic, cubic, and quartic analytic expressions are also given for each thermocouple type in various temperature ranges.
Key words: Base metal alloys; noble metal alloys; temperature scale; temperature standards; thermocouples; thermometry.