PROCESS AND ARRANGEMENT FOR PIEZOELECTRIC MEASUREMENT

摘要

A sensor containing at least one piezoelectric transducer element (1) is operated by a common signal line (2) in both possible operating modes: at low frequencies, it functions as a measurement element for a mechanical quantity by exploiting the direct piezo effect, and at high frequencies, it functions as a piezoelectric resonator by exploiting the inverse piezo effect to excite mechanical vibrations and the direct piezo effect to produce the piezoelectric reaction. A signal (uHF, uF) of higher frequency which describes the resonance characteristic and a signal (uNF, uQ) of lower frequency which describes the mechanical effect are derived from the measurement signal on the signal line (2). As a result, the performance of the sensor, together with the associated measurement amplifier, can be monitored during measurement or two different quantities can be measured simultaneously.