Absorption spectrometer and method for measuring the concentration of a gaseous component of interest in a measurement gas
US9869632B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 11, 2015 |
| Grant date | Jan 16, 2018 |
| Priority date | — |
| Expiry date | Feb 18, 2036 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2201/061
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Absorption spectrometer and method for measuring the concentration of a gaseous component of interest in a measurement gas, wherein to compensate influence of changes in an optical path length in the absorption spectrometer on a measured result, light from the laser is modulated with at least one pilot frequency in the MHz range, the measurement signal is analyzed in a phase-sensitive manner for the pilot frequency, phase information obtained during this analysis is compared with phase information obtained during calibration of the absorption spectrometer, where the measured result is corrected as a function of the difference between the two items of phase information. Alternatively, light from the laser is modulated with two pilot frequencies, where signal components contained in the measurement signal with the pilot frequencies are detected in a phase-sensitive manner and the difference between the phase information of the two signal components obtained in this operation is analyzed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.