Fault detection in electrochemical gas sensing equipment
US5202637A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 25, 1991 |
| Grant date | Apr 13, 1993 |
| Priority date | — |
| Expiry date | Sep 25, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N33/007
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A circuit is described which tests whether an amperometric electrochemical gas sensor monitoring the concentration of toxic gases in an atmosphere is working properly. The sensor has a sensing electrode, a reference electrode, and a counter electrode and in normal operation the potential between the reference electrodes is fixed by means of an operational amplifier. When there is gas in the atmosphere, the gas reacts electrochemically at the sensing electrode, causing the amplifier to supply electrical current to the counter electrode which results in an electrical potential to the sensor that is proportional to the amount of toxic gas in the atmosphere. The sensor is periodically tested to determine whether it is working properly by applying a pulse potential between the sensing and reference electrodes. If a current flow results then a signal is sent to an alarm device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.