Hazardous gas detection using an integrating sphere as a multipass gas absorption cell

Hawe, Eamonn; Fitzpatrick, Colin; Chambers, Paul; Dooly, Gerard; Lewis, Elfed

doi:10.1016/j.sna.2007.10.070

Cited by 34 publications

(17 citation statements)

References 14 publications

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“…Hodgkinson et al have analysed the distribution of optical pathlengths in these devices and shown that the resulting apparent deviation from Beer's law (equation (1)) is predictable [33] . Hawe et al have detected NO 2 and SO 2 in the 200-600 nm region using a 5 cm internal diameter integrating sphere coupled to a broadband source and a UV-visible spectrophotometer using multimode fibre [34] . The mean internal pathlength of the sphere depends on its reflectivity; for SO 2 at 280 nm this was 41 cm and for NO 2 at 370 nm it was 55 cm.…”

Section: Long Path Gas Cellsmentioning

confidence: 99%

Optical gas sensing: a review

Hodgkinson

Tatam

2012

Meas. Sci. Technol.

1,356

858

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The detection and measurement of gas concentrations using the characteristic optical absorption of the gas species is important for both understanding and monitoring a variety of phenomena from industrial processes to environmental change. This article reviews the field, covering several individual gas detection techniques including non-dispersive infrared (NDIR), spectrophotometry, tunable diode laser spectroscopy and photoacoustic spectroscopy. We present the basis for each technique, recent developments in methods and performance limitations. The technology available to support this field, in terms of key components such as light sources and gas cells, has advanced rapidly in recent years and we discuss these new developments. Finally, we present a performance comparison of different techniques, taking data reported over the preceding decade, and draw conclusions from this benchmarking.

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Section: Long Path Gas Cellsmentioning

confidence: 99%

Optical gas sensing: a review

Hodgkinson

Tatam

2012

Meas. Sci. Technol.

1,356

858

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“…The detected light power is independent of non-absorbing objects within the sample such as suspended scattering particles. This technique has been recently proposed for effective gas analyses [8,9].…”

Section: Diffuse-light Absorption Spectroscopymentioning

confidence: 99%

Diffuse-Light Absorption Spectroscopy in the VIS and NIR Spectral Ranges for Adulteration Assessment of Extra Virgin Olive Oils

Mignani

Ciaccheri

Ottevaere

et al. 2011

Lecture Notes in Electrical Engineering

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A fiber optic setup for diffuse-light absorption spectroscopy in the wide 400-1700 nm spectral range is experimented for detecting and quantifying the adulteration of extra virgin olive oil caused by lower-grade olive oils. Absorption measurements provide spectral fingerprints of authentic and adulterated oils. A multivariate processing of spectroscopic data is applied for discriminating the type of adulterant and for predicting its fraction. The Authentic Extra Virgin Olive Oil and its AdulterantsOptical spectroscopy has been frequently proposed for detecting and quantifying extra virgin olive oil (EVOO) adulteration. It allows rapid and non-destructive analysis and requires minimum sample preparation. Infrared, mid-infrared, and fluorescence

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“…Diffuse-light absorption spectroscopy, that is, spectroscopy carried out by means of an integrating cavity, is a valid alternative for overcoming scattering-dependence aspects [4][5][6][7]. Unfortunately, because it requires high-intensity sources, diffuse-light absorption spectroscopy provides low efficiency when carried out by means of optical fibers for illumination and detection.…”

Section: Motivation: the Drawbacks Of Absorption Spectroscopymentioning

confidence: 99%

Innovative spectroscopy of liquids: a fiber optic supercontinuum source and an integrating sphere for scattering-free absorption measurements

Mignani¹,

Ciaccheri²,

Cacciari³

et al. 2009

2009 IEEE Sensors

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An innovative fiber optic setup for the scattering-free absorption spectroscopy of liquids is presented. It makes use of an integrating sphere that contains the sample under test, coupled to a fiber optic supercontinuum source and to a fiber optic spectrometer. The highly-bright broadband light shining on the sphere's surface is diffusely reflected and collected by the fibercoupled spectrometric detector. When an absorbing medium is placed in the cavity, a reduction occurs in the radiance of the sphere. The reduction is related to the absorption and volume of the medium, and is independent of non-absorbing objects within it, such as scattering particles. A collection of turbid lubricant oils was considered as a test case for verifying and validating the innovative scheme of diffuse-light absorption spectroscopy. Scattering-free spectra were successfully measured and processed as product fingerprints for the prediction of turbine types and other parameters that indicate oil quality and wear.

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Hazardous gas detection using an integrating sphere as a multipass gas absorption cell

Cited by 34 publications

References 14 publications

Optical gas sensing: a review

Optical gas sensing: a review

Diffuse-Light Absorption Spectroscopy in the VIS and NIR Spectral Ranges for Adulteration Assessment of Extra Virgin Olive Oils

Innovative spectroscopy of liquids: a fiber optic supercontinuum source and an integrating sphere for scattering-free absorption measurements

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