| 摘要 |
<p>A flush-mounted sensor measures the pressure of a fluid within a hollow conduit (26). A sensor head (18) edge-mounts an isolating diaphragm (12) responsive to the pressure of the fluid. The isolating diaphragm (12) has a small diameter, typically less than 1/4 inch, is adjacent the fluid in the conduit (26) to reduce the dead volume of fluid adjacent the diaphragm (12), formed of a material that is compatible with the fluid. A drive rod (14) mechanically couples the isolating diaphragm (12) to a second diaphragm (16) of a variable capacitor assembly (17). The second diaphragm (16) is also edge-mounted and produces a counterforce acting on the side of the isolating diaphragm (12) opposite the side adjacent the fluid. The force of the fluid pressure acting on the isolating diaphragm (12) is transmitted by the drive rod (14) to the second diaphragm (16) where changes in the capacitance correspond to changes in the pressure. In another form the isolating diaphragm is formed as a thin, non-circular portion of the conduit wall.</p> |
