Method and device for detecting malfunction of electrostatic-capacitance pressure sensor
US11054331B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 18, 2019 |
| Grant date | Jul 6, 2021 |
| Priority date | — |
| Expiry date | Oct 25, 2039 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L9/0075
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An electrode pair that forms a pressure-sensitive capacitance Cx in the central portion of a diaphragm is called a first electrode pair (pressure-sensing electrode pair), and another electrode pair that forms a reference capacitance Cr in the circumferential portion of the diaphragm is called a second electrode pair (reference electrode pair). The ratio ΔCx/ΔCr of a change ΔCx in the pressure-sensitive capacitance Cx, which is obtained from the pressure-sensing electrode pair at the time of evacuation, to a change ΔCr in the reference capacitance Cr, which is obtained from the reference electrode pair at the time of evacuation, is calculated as an index for malfunction detection α. Then, the index for malfunction detection α thus calculated is compared with the reference value αref, which represents the index observed during normal operation, and whether deformation due to a cause other than pressure has been generated in the diaphragm is determined.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.