A DESIGN PROCEDURE FOR THERMOCOUPLE PROBES

An analytical procedure for the design of thermocouple probes for the accurate measurement of gas temperatures under steady state conditions is presented. Basic heat transfer concepts are used in the design of the probe envelope to provide an environment for the junction which is conducive to accurate gas temperature measurement. The procedure is illustrated by the design of a probe for measuring gas temperature in the range of 100°F with an error limit of 0.2°F at Mach numbers ranging from 0.2 to 1.0. Test results from this probe show a maximum error of 0.18°F, substantiating the design procedures.