ELECTROCAPASITIVE TYPE FORCE MEASURING APPARATUS

摘要

A sensor unit (11) comprises an elastic part (12) and a base part (13), unit ed integrally, which include opposed electrodes on their sides to form a capacitor, of which the change in capacitance is utilized to measure the for ce acting on a probe (14) attached to the end of the elastic part. These electrodes are connected with a resonance circuit of a high-frequency oscillator (22), and a digital frequency counter (23) measures the output signal from the high-frequency oscillator for a predetermined time to measur e the change in resonance frequency with the varying force. A capacitive force gauge having such a structure exhibits an extremely high sensitivity to measure minute force independently of changes in temperature or humidity, an d the sensitivity will not change with time.