Method for calibration of chemical sensor in measuring changes in chemical concentration
US6360582B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 18, 2000 |
| Grant date | Mar 26, 2002 |
| Priority date | — |
| Expiry date | Jan 18, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N33/004
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Changes in the concentration of a chemical, such as a gas, are determined using a non-linear chemical sensor which is subject to shifts in calibration over time. In order to minimize errors caused by such shifts in calibration a first infrared signal (Ig(1)) is measured and using an absorption value under an assumed chemical concentration (C(1)), a zero chemical signal Io(1) is calculated using the known physical law and mathematical relation Absorption=1−Ig/Io. A second infrared signal (Ig(2)) is then measured and the absorption value is calculated using the previously calculated zero chemical signal. A second concentration (C(2)) is then determined and the change in concentration is calculated by subtracting C(2) from C(1).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.