Static and Dynamic Response of a Cu-Ni Thin Film Heat Flux Sensor

Abstract

A Cu-Ni thin film heat flux sensor had been fabricated on a 0.05mm thick polyimide film substrate by vacuum coating technology. The overall dimension of the sensor was 8 mm long and 4 mm wide. A thermopile and a thermocouple were arranged on the substrate to measure both heat flux and surface temperature. The thermopile had 18 thermocouple junctions which formed 9 pairs of differential thermocouples and were covered by two different thickness of thermal resistance layers. This research carried out static and dynamic tests of the thin film heat flux sensor. Seebeck coefficient of thermocouple is 19.3761μV/(°C). Sensitivity of the thermopile is 0.010121μV/(W/m2). Steady-state tests of the thermopile and the thermocouple were taken separately. Time constant of the thermocouple is about 0.26s, which is faster than the thermopile of 1.57s.