Method and apparatus for measuring methane concentration in gas
US4567366A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 26, 1983 |
| Grant date | Jan 28, 1986 |
| Priority date | — |
| Expiry date | Sep 26, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2201/08
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for measuring the methane concentration in a gas, which comprises transmitting light having at least one wavelength band selected from a band of 1.6 .mu.m and a band of 1.3 .mu.m through an optical fiber having a small transmission loss in said wavelength bands to a measuring cell where an ambient gas comes in and out, absorbing the light in at least one characteristic absorption wavelength of methane gas, selected from a wavelength of 1.666 .mu.m and a wavelength of 1.331 .mu.m, in said measuring cell, transmitting the light through an optical fiber having a small transmission loss in at least one wavelength band selected from a band of 1.6 .mu.m and a band of 1.3 .mu.m to a band-pass filter, separating the light into at least one light having the methane gas absorption wavelength, that is, the wavelength to be measured, and at least one light having other reference wavelength, determining the intensity ratio of the light having the wavelength to be measured to the light having the reference wavelength, and calculating the methane gas concentration in the measuring cell from the so-determined intensity ratio.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.