Heterodyne system and method for sensing a target substance
US5022757A · kind A · utility
Inventor
Key dates
| Filing date | Jan 23, 1989 |
| Grant date | Jun 11, 1991 |
| Priority date | — |
| Expiry date | Jan 23, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2201/06113
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system and method for sensing a target substance in a medium by directing at least first and second beams of radiation to intersect within the medium and establish one or more sensing volumes. The beams have different frequencies to generate a beat frequency at the sensing volume. A selected optical effect, based on an optical property of the target substance within the sensing volume, on the first and second beams is detected at at least one selected spectral line. A signal is generated representative of the selected optical effect, such as absorbance or fluorescence, and the portion of the signal which is substantially at the beat frequency is combined with at least one selected value to determine the amount of the target substance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.