Double-reference wavelength infrared gas sensor and method

Abstract

The invention provides a double-reference wavelength infrared gas sensor and a method. The infrared gas sensor comprises a light source, a measurement detector and a reference detector; the infrared gas sensor further comprises an optical filter which is arranged on the upstream of the reference detector in a reference light path; when the radiation spectrum of the light source changes, the change rate of a scale factor K<m>, related to the measurement detector, of a measurement channel at the measurement wavelength lambda<m> is calculated through a formula (please see the formula in the description), wherein delta r<1> represents the change rate of a scale factor K<r1>, related to the reference detector, of a reference channel at the reference wavelength lambda<r1>, delta r<2> represents the change rate of a scale factor K<r2>, related to the reference detector, of the reference channel at the reference wavelength lambda<r2>, and lambda<r2>> lambda<m>> lambda<r1>. The double-reference wavelength infrared gas sensor and the method have the advantage that responding is quick and accurate.

Description

technical field [0001] The invention relates to gas detection, in particular to a dual reference wavelength infrared gas sensor and method. Background technique [0002] Infrared gas sensors generally use tungsten filament lamps as infrared light sources. Tungsten filament lamps have the advantages of small size, low power consumption, and long service life. However, the tungsten filament lamp becomes a light source by heating with electricity, and the relationship between its infrared radiation spectrum and the temperature of the light source conforms to Planck's radiation law, that is, as the temperature of the light source changes, the infrared radiation spectrum will change. [0003] In order to achieve the purpose of accurately measuring the gas concentration, the infrared sensor generally needs to be fed with gas for zero adjustment and calibration. During the process of gas passing into the infrared sensor optical chamber, the airflow in the optical chamber conducts ...

AI Technical Summary

Problems solved by technology

During the process of gas passing into the infrared sensor optical chamber, the airflow in the optical chamber conducts convective heat exchange with the high-temperature components in the optical chamber, such as tungsten filaments, so that the temperature of the tungsten filament lamp will change, resulting in changes in the radiation spectrum emission , which in turn leads to the drift of the output signal of the infrared optical detector

After the entire measurement light chamber is ventilated, it takes several hours to reach the thermal equilibrium state again, and the signal of the infrared detector will stabilize, and the response is slow.

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