Novel Temperature Drift Compensation for MEMS Thermal Wind Sensors by Heating Power Calibration Circuits

In this article, a new temperature drift compensation method using variable circuit parameters is proposed for micro-electromechanical systems (MEMSs) thermal wind sensors. Different temperature coefficients of resistance between heating resistor and ambient temperature resistor, together with mismatched resistor, give rise to temperature drift, which has been analyzed. An adjustable resistor is introduced in parallel with ambient temperature sensing resistor, achieving a new equivalent resistance Rs'. The temperature drift can be eliminated by recording the resistance at different temperatures. The sensors were tested in the temperature chamber and their heating power were compared to the calculations. Above all, the speed experiments have been performed in the wind tunnel with the temperature varying from 0 degrees C to 40 degrees C. The results indicated that the maximum wind speed errors in constant temperature difference (CTD) mode were close to 1.027, 0.611, and 0.530 m/s for the three sensors after compensation. The maximum related errors are less than 2.70%, 2.17%, and 2.24%, respectively. Compared to the uncompensated devices, the errors have been reduced by about 91.28%, 89.67% and 83.23%, respectively.