A compensation method of a drift on a vibrating sensor due to an air density

Vibrating sensors are used as a sensor to measure such as pressures, forces, accelerations and densities. In particular, a tuning fork sensor is suitable as a sensor for a electronic balance due to high sensitivities to the force and its long term stabilities. However, the tuning fork sensor is affected by a temperature and an air density. Therefore, the tuning fork sensor should be compensated the effects of them. In a conventional method, the tuning fork sensor could not be compensated adequately for an abrupt change in the air density due to a delay of a smoothing filter. In this paper, we propose accurate compensation method of a drift of the tuning fork sensor which is caused by a changing the air density. Applying Kalman filter, the drift of the tuning fork sensor can be very small even when the abrupt change in the air density and there is a noise in a measured air pressure and its frequency.