Simple multi-channel NDIR gas sensors
US7329870B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 5, 2005 |
| Grant date | Feb 12, 2008 |
| Priority date | — |
| Expiry date | Aug 7, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/3133
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Concentrations of N gas species can be detected from a single beam NDIR gas sensor having a differential infrared source and an (N+1)-passband filter (having a neutral passband and N absorption passbands for N gases) mounted at a single infrared detector by driving the infrared source with N input power levels to render the source into emitting at N distinct temperatures whose radiation outputs are characterized by N corresponding Planck curves which are dependent only upon the respective source temperatures and which link a Spectral Radiant Emittance MsubLamba with wavelength, measuring N detector outputs at the single infrared detector and detecting the concentrations of N different gas species, each of the N gas species having its own unique infrared absorption passband, by (a) setting up N causality relationship equations linking outputs of the detector respectively for N different source temperatures and a set of relevant parameters of the sensor components, (b) determining the values of all of the parameters for the N equations utilizing appropriate boundary conditions except the N concentrations for the respective N gas species, and (c) solving for the N gas concentrations w…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.