Standard tables for chromel-alumel thermocouples

Abstract

Tables have been prepared giving the thermal emf of chromel P vs alumel, chromel P vs platinum, and alumel vs platinum at various temperatures in the range-310 to 2,500° F. The values in the range 0 to 2,500 0 F are based on the calibration of 15 representative no. 8 gage chromel-alumel thermocouples selected after preliminary tests on 50 heats of each alloy made by the method regularly used. The tables give the temperature-emf relation of the thermocouples now being manufactured as closely as the wires can be reproduced at the present time. The guarantee limits have been fixed by the manufacturer at ± 5° F in the range o to 660° F and to ± % percent in the range 660 to 2,300° F. The methods used in calibrating the thermocouples in the various temperature ranges are briefly described. CONTENTS