Oxygen concentration sensing apparatus
US4804454A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 19, 1987 |
| Grant date | Feb 14, 1989 |
| Priority date | — |
| Expiry date | Mar 19, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/4065
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An oxygen concentration sensing apparatus includes an oxygen pump element and a sensor cell element to be placed in a gas under measurement, and a device for generating a voltage value command indicating a voltage to be generated across electrodes of the sensor cell element. A current limit device is provided so that the supply of the voltage value command is stopped to decrease a pump current to the oxygen pump element gradually when the voltage generated across the electrodes of the sensor cell element exceeds a first predetermined voltage, and the pump current to the oxygen pump element is reduced immediately when the voltage generated across the electrodes of the sensor cell element exceeds a second predetermined voltage which is higher than the first predetermined voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.