Open AccessResearch on the real-time measurement system based on QEPAS
Author(s) -
王贵师,
易红明,
蔡廷栋,
汪磊,
谈图,
张为俊,
高晓明
Publication year - 2012
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.61.120701
Subject(s) - computer science , laser , tunable diode laser absorption spectroscopy , diode , software , lock in amplifier , amplifier , measure (data warehouse) , time delay and integration , optics , materials science , distributed feedback laser , optoelectronics , physics , telecommunications , bandwidth (computing) , database , computer vision , programming language
A real-time measurement of gases based on QEPAS is introduced. For eliminating fluctuation of laser, a simple method, in which a digital PID algorithm and a software lock-in amplifier designed by using Lab-VIEW are employed, is utilized to lock the laser to the center of the absorption line. In order to test the system, an absorption line of water vapor near 1.396 m is chosen by using a fiber-coupled distributed feedback (DFB) diode laser. An over-40-hours continuous measurement is implemented, and the relevant results are presented and discussed. The detection limit of the system is 1 ppm. This method can also be used to measure the trace gases and monitor the industry gases.