| 摘要 |
<p>A fluid pressure sensor (10) includes a capacitive pressure sensing element (12) having a thin, relatively flexible ceramic diaphragm (14) mounted in closely spaced apart relation to a rigid ceramic substrate (16) by a glass annulus (18) mounted in a housing (28) having a port (28a) for fluid whose pressure is to be sensed by being received on an outer face (12a) of the diaphragm. An electronic circuit (36) is mounted in a chamber (20a) formed between a connector (20) and an outer face (12b) of the substrate. An electrically conductive coating (14b) is placed on the outer face (12a) of the diaphragm and an annular electrically conductive gasket (30) is disposed between the diaphragm and the bottom floor (28c) of the housing surrounding a fluid inlet (28a) in order to effect an electrical path between the conductive layer on the diaphragm and the housing. An O-ring (32) of polymer compatible with the fluid being sensed is disposed within the annulus of the conductive gasket to serve as a fluid barrier in selected applications. In other applications, particularly those in which the pressure of the sensed fluid is low, the conductive gasket serves both as an electrically conductive member and as a fluid seal with the O-ring being eliminated. <IMAGE></p> |
