A low pressure meter based on a capacitive micro sensor

An implementation of a low pressure meter based on a capacitive micro sensor is exposed in this paper. In the first part, we presented the analysed sensor's structure and the developed theoretical model that permits to simulate the variation of its capacitance under applied absolute pressure. Keeping in mind that the variation of the sensor's capacitance is non linear and to allow for a direct measure of applied absolute pressures in a specified range and with a specified resolution, we proposed geometrical sizes for the design of the studied sensor. From the theoretical study, we deduced a suitable model for low pressure measurement. Considering this model, we developed in the second part an electronic associated conditioner using a differential sensing procedure that permits the direct display of low pressures with a desired resolution. An experimental setup with some results was shown by the end to confirm the validity of the proposed model. (C) 2009 Elsevier B.V. All rights reserved