Apparatus and method for automatic detection of diaphragm coating or surface contamination for capacitance diaphragm gauges
US9677964B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 28, 2015 |
| Grant date | Jun 13, 2017 |
| Priority date | — |
| Expiry date | Jun 9, 2035 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L21/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system and a method detect contamination of a diaphragm in a capacitance diaphragm gauge wherein a contaminated diaphragm deflects less in the presence of pressure than an uncontaminated diaphragm. The system and method measure a base pressure. A DC voltage is applied between the diaphragm and a fixed electrode to cause the diaphragm to deflect to simulate an effective pressure. The system and method measure a combined pressure caused by the base pressure and the effective pressure. The system and method subtract the base pressure to determine the effective pressure caused by the static diaphragm deflection. If the measured effective pressure is less than an acceptable effective pressure, the system and method determine that the diaphragm is contaminated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.