| 摘要 |
A differential pressure measuring cell includes a capacitive-type measuring chamber having a relatively rigid diaphragm, an auxiliary chamber having a relatively flexible diaphragm, a casing defining first and second recesses surrounding the auxiliary and measuring chambers, respectively, passages connecting one side of the auxiliary chamber and measuring chamber with the first recess and a first pressure-receiving chamber, and passages connecting the other side of the auxiliary chamber and measuring chamber with the second recess and a second pressure-receiving chamber. Radial expansion of the auxiliary and measuring chambers is prevented by the static counterpressures present in the first and second recesses. Over pressure protection is provided by the small volumes of the first and second pressure-receiving chambers and the greater flexibility of the auxiliary diaphragm, whereby the auxiliary diaphragm will absorb the entire pressure differential before the measuring diaphragm engages the walls of the measuring chamber.
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