Gas sensing apparatus
US9417207B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 9, 2012 |
| Grant date | Aug 16, 2016 |
| Priority date | — |
| Expiry date | Jan 8, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/4045
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method of selectively sensing the concentration of a target gas in polluted ambient air comprises the steps of: —providing a target gas sensor (220) sensitive to the target gas; —providing a first gas flow derived from the ambient air, from which first flow the target gas is substantially removed; —providing a second gas flow derived from the ambient air, substantially comprising the same target gas concentration as the ambient air; —exposing the target gas sensor to the first gas flow during a first time interval, and obtaining from the sensor a first output signal (Smf); —exposing the target gas sensor to the second gas flow during a second time interval not overlapping with the first time interval, and obtaining a second output signal (Smu); —calculating the difference (SΔ) between the first and the second output signals; calculating the concentration of the target gas from the calculated signal difference (SΔ).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.