A THREE-AXIS THERMAL ACCELEROMETER

The paper presents the numerical design and performance of a triple-axis thermal accelerometer. In a typical thermal accelerometer, a heater is suspended at the center and sensing elements are located around the heater on the opening side of a cavity. Consequently, the sensitivity of the vertical axis measurement is very low in comparison with the horizontal axes measurements and the cross-sensitivity between these measurements is very high. In our new design, the heater is formed a wide ring and the sensing elements are located both inside and outside of the heater ring with a small elevation from the heater plane. The obtained results show that the sensitivity of the vertical axis measurement attains to the order of the horizontal axes measurements. The cross-sensitivities among three axes are less than 4%. For instance, at the supplied power of 15mW to the heating resistor, the sensitivity of the accelerometer is 0.12 degrees C/g in the vertical axis and 0.25 degrees C/g in the horizontal axes.