Pressure-measuring arrangement with high linearity
US5445031A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 1, 1994 |
| Grant date | Aug 29, 1995 |
| Priority date | — |
| Expiry date | Jun 1, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L9/12
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A pressure-measuring arrangement has a pressure-sensor structure with a diaphragm whose pressure-dependent deflection is measurable capacitively by means of a first electrode (=measuring electrode) disposed on the diaphragm and forming a measuring capacitance, C.sub.s, together with a fixed counter-electrode. A second electrode forming a second pressure-dependent capacitance, C.sub.f, together with the counter-electrode is implemented and disposed on the diaphragm. A third electrode forms a constant reference capacitance, C.sub.r, together with the fixed counter-electrode. An evaluating circuit derives the pressure by a capacitance measurement and has the following transfer function: EQU F=[C.sub.s (p)-C.sub.r ]/C.sub.f (p). The first electrode and the second electrode are separated by a boundary having an angularly extending profile optimized with respect to a minimal linearity error. This profile varies as a function of the variable radius of the first electrode and the variable radius of the second electrode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.