| 摘要 |
A force, weight or displacement sensor assembly (2) which incorporates a multi-plate capacitor system having drive and pick-up plates mounted on an appropriate suspension system to provide for desired relative motion. The fixed plates (8, 12) are driven with an AC carrier signal (40) on the order of 50 kHz with the signal to the outer most plates being 180 degrees out of phase with each other. The output signal is run through a buffer amplifier of very high impedance, and then synchronously demodulated to produce a DC signal proportional to force, weight or displacement. A force (including weight) or displacement is applied to the pick-up plate (20). For example, a sample holder (24) or means for transmitting force is provided which is mounted to move in unison with the pick-up plate (20). Movement of the pick-up plate produces an output which is proportional to the pick-up plate position, but easily calibrated to represent force since the sensor of the present invention has a linear force versus displacement relationship. |
