PIEZO ELECTRIC RESONATOR DIFFERENTIAL ACCELEROMETER

摘要

A monoaxial differential accelerometer with frequency output, includes a thin monolithic piezoelectric sensitive plate (10) in which plane a sensitive axis (X) is located. The plate (10) comprises two rectilinear slits (15, 15') parallel with the sensitive axis (X) and defining between them two zones of vibration aligned along the sensitive axis (X) and identically sensitive to the temperature variations. Each vibration zone is located between two electrodes (3, 4, 3, 4') to form resonators (20, 21) whose frequency variations are added for an acceleration directed along the sensitive axis (X) and whose the frequency variations are subtracted for an acceleration directed in a plane perpendicular to the sensitive axis (X). The resonators (20, 21) are inserted in the circuits of two oscillators (73, 74) whose beat frequency constitutes the output signal of the differential accelerometer.