Gas monitoring using electrochemical cell and method of operating
US7504959B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 20, 2007 |
| Grant date | Mar 17, 2009 |
| Priority date | — |
| Expiry date | May 31, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N33/0063
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for gas detection uses a sensor such as an electrochemical (EC) cell and includes a feedback control loop to control a pump to establish a first predetermined gas flow rate to the EC cell. The concentration of the gas at the first predetermined flow rate is measured. If the detected concentration exceeds a predetermined Alert value at the first flow rate an Initial Warning without remedial action is generated, and, the system then changes the gas flow rate before an Alarm is indicated. An Alarm is signaled only if the system verifies the first measurement. Preferably the first flow rate is set to optimize the measurement accuracy of the EC cell being used, and the second flow rate is lower than the first. Verification of an Alarm at the first flow rate may be conducted quickly by a quick-reaction process. The controller may periodically cycle the flow rates between the first and second rates for better accuracy and faster verification times.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.