| US 7,331,239 B1 | ||
| Self calibrating dual diaphragm pressure sensor | ||
| Tzu-Yu Wang, Maple Grove, Minn. (US); Eugen I Cabuz, Edina, Minn. (US); and Mihai Gologanu, Bucharest (Romania) | ||
| Assigned to Honeywell International Inc., Morristown, N.J. (US) | ||
| Filed on Sep. 26, 2006, as Appl. No. 11/527,336. | ||
| Int. Cl. G01L 9/12 (2006.01) | ||
| U.S. Cl. 73—718 [73/724] | 20 Claims |

| 1. A device for sensing pressure, comprising:
a sealed chamber defining part having an upper portion and a lower portion and a gage pressure port in said upper portion
and a input pressure port in said lower portion;
a primary flexible diaphragm having two sides and mounted in communication with the upper portion in said sealed chamber defining
part, said primary flexible diaphragm having a conductive surface on both sides;
a secondary flexible diaphragm having two sides and mounted in contact with said primary flexible diaphragm, said secondary
flexible diaphragm having a conductive surface on the side facing said primary flexible diaphragm;
said primary and secondary flexible diaphragms defining said upper portion and said lower portion respectively and each having
at least one hole in their respective surfaces, said holes being offset from one another such that each diaphragm seals the
holes in the other diaphragm surface; and
electrical connections contacting said primary and said secondary flexible diaphragms and selectively adapted to energize
either or both of said diaphragms;
whereby energizing said secondary diaphragm binds said diaphragms together such that applied pressure deflects the bound diaphragms
and provides a capacitive response between said upper part of said sealed chamber and said primary diaphragm in proportion
to the pressure being measured.
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