Measuring force by sensor electrostatic force - contg. compensating pendulum pivoted between measuring and force compensating electrodes

摘要

At least one pendulum (1) is pivotably positioned between at least one pair of measuring electrodes (3,4) initiated by an a.c. voltage and at least one pair of compensating electrodes (8,9). The pendulum delivers at least one current for further processing to an evaluating unit (11). An equal and constant potential is applied to the compensating electrodes for compensating the force. The evaluating unit supplies a rectified measurement signal (US) which is used to modulate the potential applied to the compensating electrodes. This modulation is carried out such that one electrode receives the sum and the opposite electrode receives the difference between the applied potential and the measurement signal. ADVANTAGE - No damaging feedback to measurement signal can occur allowing sensitivity to be increased. Relatively simple to adjust since us square relationship affects the measuring accuracy.