A thermal convective accelerometer system based on a silicon sensor—Study and packaging

In the present work a thermal accelerometer without solid proof mass, based on a silicon sensor was studied. Its principle of operation is based on the acceleration induced thermal exchange variations due to convection between a heater and two series of thermocouples. A specially designed housing was fabricated, which allows the device to be covered with various liquids. The effect of the different liquid viscosities on the sensor characteristics was examined. The dependence of the accelerometer signal on both frequency and acceleration was determined for various configurations. It was found that depending on the packaging configuration the 3 db cut-off signal can be adjusted from some Hertz to several hundreds of Hertz. The sensitivity of the device as well as the accuracy of the waveform shapes can also be adjusted by regulating specific packaging parameters. A specially designed electronic interface was implemented for monitoring and controlling the input and output signals of the accelerometer. Different modes of operation were considered in order to improve the long term stability of the device.