Gas parameter online measurement method based on wavelength modulation spectroscopy

A technology of wavelength modulation spectrum and gas parameters, which is used in the fields of concentration, measurement of gas temperature, pressure and spectral constant, and can solve the problems of inability to measure gas pressure and spectral constant.

Active Publication Date: 2012-09-19
TSINGHUA UNIV
View PDF3 Cites 43 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0018] In order to solve the problem that wavelength modulation spectroscopy needs to carry out complex calibration experiments through second harmonic peaks to determine gas temperature and concentration and cannot measure gas pressure and spectral constants, the purpose of the present invention is to provide a gas absorption in wavelength modulation spectroscopy The rate function fitting method can directly determine the temperature, concentration, pressure and spectral constant of the gas

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Gas parameter online measurement method based on wavelength modulation spectroscopy
  • Gas parameter online measurement method based on wavelength modulation spectroscopy
  • Gas parameter online measurement method based on wavelength modulation spectroscopy

Examples

Experimental program
Comparison scheme
Effect test

experiment example

[0093] 1) Take NH 3 Take the mixed gas with air as an example, select the absorption spectrum line from the HITRAN spectral database, and its center frequency v 0 6529.184cm -1 ;

[0094] 2) Using the tunable semiconductor laser 5 as the light source, adjust the temperature and current of the laser controller 4, so that the output frequency of the tunable semiconductor laser 5 is stabilized at the center frequency v 0 place, and use the wavelength meter 6 to calibrate and monitor;

[0095] 3) The 20Hz sawtooth wave generated by the signal generator 1 and the 10kHz sine wave generated by the lock-in amplifier 2 are superimposed by the adder 3 and then input to the laser controller 4, and the laser generated by the driving laser is at the frequency of the absorption spectrum line Scanning and modulation occur, the modulation coefficient m≈1.5, and the phase difference between frequency modulation and intensity modulation Ψ=45.5°;

[0096] 4) The laser light emitted by the la...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention relates to a gas parameter online measurement method based on wavelength modulation spectroscopy and belongs to the field of tunable diode laser absorption spectroscopy. According to the method, a gas absorptivity function is fitted by using an odd number of harmonic signals of an X axis and a Y axis output by a phase-locked amplifier based on the wavelength modulation spectroscopy, normalization processing is carried out on the harmonic signals of the X axis and the Y axis by using first harmonic background signals so as to eliminate the influence of factors, such as background signal, laser intensity and modulation factor, and then, the temperature, concentration, pressure and spectroscopic constant of gas are directly measured by using the gas absorptivity function. The gas parameter online measurement method based on the wavelength modulation spectroscopy has the advantages that the problem that the wavelength modulation spectroscopy needs to calibrate experimental measuring temperature and concentration and cannot measure the pressure and spectroscopic constant of gas nowadays is solved, and the application range of the wavelength modulation spectroscopy is widened.

Description

technical field [0001] The invention relates to an online measurement method of gas parameters, in particular to fitting a gas absorption rate function based on wavelength modulation spectrum technology, and then measuring gas temperature, concentration, pressure and spectral constant. Background technique [0002] Real-time online detection of environmental pollution gases, flammable and explosive gases, and combustion atmosphere is a key technology in environmental protection, industrial safety production, energy saving and emission reduction. Tunable diode laser absorption spectroscopy (TDLAS) is an advanced, non-contact online detection technology for gas temperature, concentration and pressure developed in recent years. This technology uses a laser with an extremely narrow bandwidth to scan the characteristic absorption lines of gas molecules, which can effectively remove the interference of other spectral lines, and has extremely high wavelength selectivity and sensiti...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): G01D21/02G01N21/39
Inventor 丁艳军彭志敏周佩丽
Owner TSINGHUA UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap