METHOD TESTING AND STABILIZING SENSITIVITY OF CAPACITIVE CONVERTER Russian patent published in 1999 - IPC

FIELD: acoustic measurements based on contact-free methods of excitation and reception of ultrasonic vibrations. SUBSTANCE: vibrations of counter electrode put on sample are excited by means of generator. Vibrations of counterelectrode converted by capacitive converter to electric signal are fed to device isolating vibrations. Test of sensitivity is conducted by characteristic parameters of this signal, for instance, by magnitude of signal amplitude in specified point. With deviation of characteristic parameter from preset magnitude feedback signal is generated and fed to source of polarizing voltage. Voltage across output is so regulated that given signal goes to zero. Thus stabilization of sensitivity of capacitive converter is conducted in process of its operation and measurement precision is enhanced by way of exclusion of random and systematic components of errors. EFFECT: enhanced measurement precision and conducting of stabilization of sensitivity of converter in process of its operation. 2 dwg