| 摘要 |
<p>The apparatus of the invention includes a sensor header and a sensor cover which are coupled to a prior art diaphragm assembly. The sensor header is provided with two piezoresistive silicon membrane strain gauges. One side of both strain gauges is exposed to fluid at upstream high pressure. The other side of the first strain gauge is exposed to fluid at downstream low pressure and the other side of the second strain gauge is exposed to the atmosphere. The sensor header is provided with a first port which is fluidly coupled to the first membrane strain gauge and extends to the surface of the header at a first location. The sensor header is provided with a second port which is fluidly coupled to the second membrane strain gauge and extends to the surface of the header at a second location. The sensor cover defines two isolated annular spaces around the sensor header, a first annular space around the first location and a second annular space around the second location. The first annular space is fluidly coupled to the low pressure port of a conventional diaphragm assembly and the second annular space is fluidly coupled to the atmosphere.</p> |
