Combination pressure sensor with capacitive and thermal elements
US6619131B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 14, 2002 |
| Grant date | Sep 16, 2003 |
| Priority date | — |
| Expiry date | Mar 14, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L21/12
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A pressure sensor has a baseplate and a support plate with a membrane. Layers on the membrane and the support plate are connected to a circuit for capacitively measuring pressure to generate a first pressure signal. A thermal conductivity measuring element that generates a second pressure signal has a heating element connected to the baseplate adjacent the support plate at a location opposite from the membrane for protecting the membrane from thermal effects. The method uses the sensor apparatus to generate an output signal representing a measured result when the measured result is above a transition value, on the basis of the first pressure signal and, when the pressure falls below a threshold value, any offset of the first pressure signal is compensated in such a way that determination of the output signal on the basis of the first pressure signal leads to the same result as determination of the output signal on the basis of the second pressure signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.