摘要 |
A fluid pressure gauge comprises a unitary, sealed, U-shaped hollow tube (12) with an electrically conductive ribbon (14) stretched between the ends of its arms (18). Fluid pressure applied to the interior of the tube via an inlet (24) on the axis of symmetry tends to straighten the tube, thereby varying the tension in the ribbon. The tension, and thus the pressure, are sensed by measuring the natural frequency of electromagnetically-maintained transverse vibration of the ribbon. Adjustment of the initial tension of the ribbon enables temperature sensitivity of the gauge to be reduced. One arm of the tube can be omitted, the ribbon being connected chordally across the curved portion and the pressure being applied through the remaining arm, or alternatively the tube can be serpentine in form. |