Design, calibration and testing of transient thin film heat transfer gauges

Abstract

A method for the design, construction, calibration and testing of thin film platinum resistance temperature detectors (RTDs) is described. The calibration and testing was performed to determine if RTDs can be used for measuring surface temperatures and heat transfer rates under transient conditions. By depositing a thin film of platinum on the surface of a highly polished ceramic substrate, RTDs were obtained which have a temperature coefficient of resistivity of 0.0019 K, an adequate linear behavior, and a thermal product of 0.2 J/cm/K/s. Furthermore, the construction techniques produced gauges that were reliable, reproducible, and rugged. The results from shock tube tests showed that the RTDs had a time response on the order of microseconds and were suitable for making heat transfer measurements in highly transient conditions. Suggestions for further developments are included.