Comparative analysis between thin-film gauges and ALTP sensors in shock tunnel tests

In the shock tunnel tests, the main parameter to measure is the heat flux density, and the thin-film resistance gauges （TFRGs） are frequently used. As the uncertainty of the measured heat flux with TFRGs is relatively high resulting from the lack of direct validation method for TFRGs, the atomic layer thermopile （ALTP） heat-flux sensors are applied in shock tunnel tests for comparison with the TFRGs. ALTP sensors have a fast response time and a good linearity, and it can be used in a long duration to measure low heat flux density, which ensures that they can be easily calibrated with the high-accuracy light-based calibration device, so the transfer calibration method is established to on-line calibrate TFRGs in the shock tunnel tests. The experimental results confirm the stable measured heat flux with the ALTP sensors and the TFRGs in the different shock tunnel tests, and the difference between the two kinds of heat-flux sensors is less than 8%. Based on the discussion on the tracing chains of the transfer method for calibrating heat-flux sensors and the measured heat flux in tests, the comparison results show the potential that the ALTP heat-flux sensors can be used to on-line calibrate TFRGs in shock tunnel tests.