Residual pressure measurement system for Fabry-Perot cavity of optical MEMS pressure sensor and method thereof
US11473992B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 23, 2018 |
| Grant date | Oct 18, 2022 |
| Priority date | — |
| Expiry date | May 3, 2039 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L27/002
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention discloses a residual pressure measurement system for a MEMS pressure sensor with an F-P cavity and method thereof, the measurement system includes a low-coherence light source, a 3 dB coupler, a MEMS pressure sensor, an air pressure chamber, a thermostat, a pressure control system, a cavity length demodulator, an acquisition card and a computer. The measurement method comprises: performing cavity length measurement by using the reflecting light by the pressure control system at two temperatures, respectively, so as to calibrate the MEMS pressure sensor and establish a relationship between the absolute phase of a monochromatic frequency and the external pressure; performing linear fitting to the two measurement data to obtain all the external pressure when the cavity length of two measurement data are equal to each other, and substituting the theoretical equation for calculation to obtain the residual pressure under the flat condition of the diaphragm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.