A PIEZOELECTRIC BIMORPH STATIC PRESSURE SENSOR

In this paper we describe a new resonance piezoelectric sensor for pressure measurement. The active element is a cheap piezoceramic membrane of the type used in piezoelectric 'buzzers' and telephone receivers. The membrane is elastically supported ail around by gluing its border to the edge of a rigid closed chamber. The resonance flexural frequency of the membrane is largely dependent on the applied pressure, due to the non-linear behaviour of the bond. The membrane is driven in oscillation by a simple feedback circuit and the resonance frequency is proportional to the pressure within a large range. The sensor is very inexpensive, accurate and sensitive; it has good repeatability and uses very simple electronics.