Title :
Optical Measurement of Water Vapor Concentration and Gas Pressure
Author :
Qiang Wang ; Jun Chang ; De Long Kong ; Yong Ning Liu ; Fu Peng Wang ; Cun Guang Zhu ; Wei Wei ; Xiang Zhi Liu
Author_Institution :
Key Lab. of Laser Technol. & Applic., Shandong Univ., Jinan, China
Abstract :
A technique is proposed to realize simultaneous measurement of water vapor concentration and total gas pressure. The technique is based on distributed feedback laser diode wavelength scanning, and it is in conjunction with Levenberg-Marquardt algorithm (LMA). Water vapor concentration at a pressure of 5.7 atm has been measured with a differential value between the peak value and the base line, which is derived from the fitting absorption spectrum after LMA processing; and measuring accuracy has been achieved. Simultaneously, gas pressure inside the gas cell can be obtained by calculating full width at half maximum after application of this fitting algorithm, and an accuracy better than 5% has been achieved in a range of 1.02-7.48 atm.
Keywords :
absorption; chemical variables measurement; distributed feedback lasers; gas sensors; measurement by laser beam; optical sensors; optical variables measurement; semiconductor lasers; vapour pressure measurement; LMA; Levenberg-Marquardt algorithm; distributed feedback laser diode wavelength scanning; fitting absorption spectrum; optical measurement; pressure 5.7 atm; total gas pressure measurement; water vapor concentration measurement; Absorption; Atmospheric measurements; Fitting; Laser beams; Pressure measurement; Shape; Vectors; FWHM; Levenberg-Marquardt algorithm; high pressure; water vapor measurement;
Journal_Title :
Sensors Journal, IEEE
DOI :
10.1109/JSEN.2013.2284279
