Method and apparatus for single-laser-sourceharmonic remote sensing gas detection

Abstract

The invention relates to a single laser source harmonic remote sensing gas detection method and equipment for realizing the method. The method is to use a sinusoidal signal of a certain frequency to modulate the laser light emitted by a diode laser with the central frequency of the absorption peak of the gas to be detected as the detection light, and the detection light is reflected (scattered) after passing through the detected area, The back (scattered) light is focused on a photodetector for photoelectric signal conversion, and the converted electrical signal is detected by two phase-sensitive detectors for the first harmonic signal and the second harmonic signal, among which the phase-sensitive detector The frequency of the reference signal is consistent with the frequency of the sinusoidal modulation signal, and the gas path-integral concentration of the detected area will be determined by the following formula: C R =K(P 2f / P 1f ), where K is determined by a calibration calibration experiment. The method of the invention is convenient for measurement and has high measurement accuracy. And it has the characteristics of high sensitivity and good real-time performance. Since only a single laser beam is emitted, the structure of the equipment for realizing the method is relatively simple and the cost is low.

Description

technical field [0001] The invention relates to spectrum remote sensing monitoring technology, in particular to a single laser source harmonic remote sensing gas detection method and equipment for realizing the method. Background technique [0002] Spectral remote sensing monitoring technology has the advantages of high sensitivity, high resolution, real-time and rapid monitoring. It can detect polluted gases in some inaccessible areas (such as chimneys, hazardous material distribution centers); it is especially useful for continuous monitoring or leak monitoring; it can measure pollutants in the troposphere and even above the stratosphere; no sampling gas is required, so no The accuracy of the sample gas is as concerned as the sampling measurement. Therefore, the large-scale continuous real-time monitoring method of spectral remote sensing monitoring technology will become an ideal tool for environmental pollution monitoring and industrial safety production monitoring. ...

AI Technical Summary

Problems solved by technology

[0009] The present invention aims at the deficiencies in the existing spectral remote sensing monitoring technology, solves the problem of using double beams in the method, solves the problems of large and complex equipment, high price, and complicated operation in the equipment or device, and provides a new spectral remote sensing monitoring method ——A method for detecting gas by harmonic remote sensing with a single laser source and the equipment for realizing the method

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