| 摘要 |
<p>A fluid pressure sensing unit (2) includes a re-usable portion (5) which is isolated from system fluids and a disposable portion (8). The disposable portion (8) includes an enclosure (11) that defines an internal cavity (35) with one wall of the enclosure (11) being constituted by a flexible diaphragm (25) that is exposed to operating pressure of the system. The re-usable portion (5) has mounted therein a sensing array (62) at a position adjacent to a non-system pressure side surface (66) of the diaphragm (25). The sensing array (62) includes a plurality of sensing elements (78-81) which are arranged as radial inner and outer sets (78, 79 and 80, 81) with each set being adapted to preferentially sense a deflection of a central portion of the diaphragm (25). An output signal representative of the fluid pressure in the fluid system is established based on a ratio of deflection signals from the sets (78,79 and 80, 81) of sensing elements (78-81). Preferably, the sensing elements (78-81) constitute capacitive plates that have equally exposed surface areas (84-87).</p> |
