Measurement system for measuring cylinder pressure in an internal combustion engine
US7709998B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 20, 2006 |
| Grant date | May 4, 2010 |
| Priority date | — |
| Expiry date | Oct 6, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L9/0025
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A plurality of exchangeable, different piezoelectric pressure sensors (4) comprise integrated SAW elements (60) as identification units whose identification data can be read by an interrogation unit (3) via a common connection cable (61). The analysis unit (2) for the measurement signals and the interrogation unit (3) for the identification data can be connected by a common coupling unit (5) to the connection cable (61). The coupling unit (5) has a coupling capacity (6) which connects with high frequency the interrogation unit (3) to the signal line of the connection cable (61), as well as a coupling inductance (7) which connects with low frequency the load amplifier (1) of the analysis unit (2) to the connection cable (61), thus neatly separating the useful signal from the identification signal and keeping a high-impedance measurement chain from the sensor (4) to the input of the load amplifier (1). An SFSCW radar can further be used to improve interrogation of the identification data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.