An auto-correction laser photoacoustic spectrometer based on 2f/1f wavelength modulation spectroscopy

An auto-correction laser photoacoustic (PA) spectrometer based on 2f/1f wavelength modulation spectroscopy (WMS) has been proposed and demonstrated for trace gas detection to eliminate concentration measurement errors due to light power variations.

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Rapid and sensitive trace gas detection with continuous wave Optical Parametric Oscillator-based Wavelength Modulation Spectroscopy

Applied Physics B ◽

10.1007/s00340-010-4242-0 ◽

2010 ◽

Vol 103 (1) ◽

pp. 223-228 ◽

Cited By ~ 13

Author(s):

D. D. Arslanov ◽

M. Spunei ◽

A. K. Y. Ngai ◽

S. M. Cristescu ◽

I. D. Lindsay ◽

...

Keyword(s):

Optical Parametric Oscillator ◽

Continuous Wave ◽

Wavelength Modulation Spectroscopy ◽

Parametric Oscillator ◽

Gas Detection ◽

Trace Gas ◽

Wavelength Modulation ◽

Trace Gas Detection ◽

Modulation Spectroscopy ◽

Optical Parametric

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An all-optical photoacoustic spectrometer for trace gas detection

Sensors and Actuators B Chemical ◽

10.1016/j.snb.2010.10.035 ◽

2011 ◽

Vol 153 (1) ◽

pp. 214-218 ◽

Cited By ~ 27

Author(s):

Qiaoyun Wang ◽

Jianwei Wang ◽

Liang Li ◽

Qingxu Yu

Keyword(s):

Gas Detection ◽

Trace Gas ◽

Trace Gas Detection ◽

Photoacoustic Spectrometer ◽

All Optical

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Kinetics of Ethanol and Acetaldehyde Production in Fermenting Wheat Dough by Laser-Based Trace Gas Detection

Food Science and Technology International ◽

10.1106/j5ru-uqnn-j7tk-9l3c ◽

2001 ◽

Vol 7 (4) ◽

pp. 307-315 ◽

Cited By ~ 4

Author(s):

S. Tomás ◽

F. J. M. Harren

Keyword(s):

Gas Detection ◽

Trace Gas ◽

Enzymatic System ◽

Trace Gas Detection ◽

Yeast Saccharomyces Cerevisiae ◽

Wheat Dough ◽

Photoacoustic Spectrometer ◽

On Line ◽

Active Dry Yeast ◽

Acetaldehyde Production

The fermentation process of wheat dough was studied by laser-based trace gas detection. A CO-laser-driven photoacoustic spectrometer was used to monitor simultaneously, in real time, the ethanol and acetaldehyde production rates of two commercial types of active dry yeast ( Saccharomyces cerevisiae) in wheat dough substrates. Both types of yeast, Oand B, produced ethanol for 5 hours. Acetaldehyde was yielded only during 100 minutes by the yeast O, whereas the yeast Bgenerated this compound for 3.5 hours. The total ethanol and acetaldehyde productions amounted to 1.50 mL/g dough and 4.5 µ L/g dough in the Ocase, and 0.84 mL/g dough and 14.75 µ L/g dough, in the Bcase, respectively. The yeasts were also tested for their ability tometabolize mixes consisting of the control wheat dough substrate and extra amounts of glucose or maltose. Both types of yeasts showed a similar ability to consume the added glucose, however, only the yeast Bwas found to possess an adapted enzymatic system to metabolize maltose. This work showed the efficiency of applying photoacoustic trace gas detection to food technology research for on-line monitoring of fermenting wheat dough.

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