Gas-concentration/humidity detection apparatus
US8603310B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 19, 2010 |
| Grant date | Dec 10, 2013 |
| Priority date | — |
| Expiry date | Apr 25, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/419
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A sensor control apparatus (3) includes a full-range gas sensor composed of an oxygen concentration detection cell having a pair of electrodes (21, 22) and an oxygen pump cell having a pair of electrodes (19, 20). In an electric circuit section (30), an Ip current flowing between the electrodes (19, 20) is controlled such that an electromotive force Vs produced between the electrodes (21, 22) becomes equal to a reference voltage. The reference voltage is usually set to a first reference voltage. However, when the subject gas is air, the reference voltage is set to a second reference voltage. Humidity of the subject gas is detected on the basis of an error ΔIp between an Ip current detected when the reference voltage is set to the first reference voltage, and an Ip current detected when the reference voltage is set to the second reference voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.