Differential-pressure apparatus employing a resonant force sensor

摘要

Differential-pressure measuring apparatus comprising a casing providing a closed chamber filled with fluid and divided into two sections by a pressure-responsive element. The input pressures are applied to the two chamber sections respectively to develop a corresponding force on the pressure-responsive element. A sealed evacuated housing of non-magnetic material is in one chamber section and contains a double-tuning-fork (DTF) the resonant frequency of which varies with longitudinal tension force applied to the DTF. The force developed by the pressure-sensitive element is coupled by magnetic elements through the wall of the housing and to the DTF so as to control the resonant frequency of the DTF in accordance with the differential pressure to be measured. The DTF is activated to produce an output signal reflecting the differential pressure.