System and method for particulate sensor diagnostic
US7609068B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 4, 2007 |
| Grant date | Oct 27, 2009 |
| Priority date | — |
| Expiry date | Apr 15, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N35/00613
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A particulate (soot) sensor system has a diagnostic feature for verifying the integrity of the wiring leads. The sensor system includes a sensor and processing circuitry. The sensor has a substrate, first and second sensing electrodes on the substrate and a heater electrode. The heater electrode is electrically isolated from the first and second sensing electrodes, although there is a parasitic capacitance between them. The processing circuitry includes a heater driver, a measurement circuit connected to the sensing electrodes by wire leads, and a detector. The heater driver, in addition to energizing the heater, produces a stimulus signal that is applied to the heating electrode, which is then coupled via the parasitic capacitance to the sensing electrodes. The detector is coupled to the wiring leads and is configured to detect the stimulus signal when there is electrical conductivity over the leads to the sensing electrodes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.