Method of controlling a short-etalon fabry-perot interferometer used in an NDIR mearsurement apparatus
US5835216A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 5, 1996 |
| Grant date | Nov 10, 1998 |
| Priority date | — |
| Expiry date | Jul 5, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/3504
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method of controlling a short-etalon Fabry-Perot interferometer used in an NDIR measurement apparatus includes generating a measurement signal using a radiant source. The measurement signal is provided to a sample point containing a gas mixture to be measured. The measurement signal is bandpass-filtered with an electrically tuneable Fabry-Perot interferometer using at least two wavelengths of the interferometer passband. The measurement signal is passed via an optical filter component prior to detection, and the filtered measurement signal is detected by a detector. During the measurement cycle, the passband frequency of the interferometer is controlled to coincide at least partially with the cutoff wavelength range of the optical filter component.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.