Response compensation of fine-wire temperature sensors

Abstract

Theoretical analysis of the frequency response of a fine-wire temperature sensor such as a thermocouple or a cold-wire was performed, and the strict solution of the response was derived by treating rigorously a boundary condition of heat transport between a temperature sensing part and its adjoining support. The solution obtained is highly universal and can express the frequency response of both a fine-wire thermocouple and a cold-wire with a single equation. The validity of the theoretical solution was examined experimentally, and a response-compensation technique widely applicable to fine-wire temperature sensors was developed based on the theoretical results. In this technique, any special apparatus for calibrating the dynamic response is unnecessary. The present response compensation technique can make fluctuating temperature measurement by a 3.2 μ m tungsten-wire well comparable to that by a 0.63 μm platinum-wire which is regarded as one of the fastest temperature sensors commercially available.