DEVELOPMENT OF HIGH-DENSITY ARRAYS OF THIN FILM HEAT TRANSFER GAUGES

摘要

An advanced heat transfer measurement and signal processing system is described. High-density thin film heat transfer gauge arrays have been developed allowing high frequency (200 kHz), high spatial resolution (0.2 mm spacing) heat transfer measurements. Multiple gauges are connected in series with a single constant current supply while voltage output is sensed through narrow leads, thus minimizing lead area. Dense gauge arrays are produced using standard sputtering and photo-etching techniques to create a completely platinum gauge and lead pattern in a single 0.04 micron thick layer. New signal conditioning electronics have been built using low noise, high bandwidth, differential input instrumentation amplifiers. The circuit incorporates a pre-emphasis filter to boost the low sensitivity of the thin film at high frequencies. A new digital IIR filter based signal processing technique is introduced which provides a more efficient and accurate conversion of the temperature signal to heat flux data.