Development of a Dual Axis Convective Gyroscope with Embedded Heater and Low Thermal-stress Thermistors

In this paper, we present a novel structure of the sensing element or thermistor for the gas gyroscope. The thermistor is heated by a heater core, which is power -supplied independently. This design allows low voltage on the thermistor so that the noise on output voltage is reduced. Both heater and thermistor are optimized in order to reduce the thermal induced stress which occurred in the old thermistors at its working temperatures. The effect of thermal stress appeared in a p-type silicon thermistors reducing the performance of sensor by 7.5%, which is calculated and confirmed by directly measuring relative change of the resistance of the thermistor. A circular flow inside the hermetic case is simulated in detail by utilizing 3D transient compressible flow with the interaction of fluid-solid phase. The working principle and the effect of the jet-pump integrated inside the sensor are explained and validated by experiments using anemometry technique.