Optoacoustic detection of sulphur dioxide below the parts per billion level

Koch, K.; Lahmann, W.

doi:10.1063/1.90023

Cited by 71 publications

(15 citation statements)

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“…Opto-acoustic spectroscopy is a variation on the absorption method, relying on the conversion of energy from a resonantly excited atom or molecule to thermal energy in the surrounding material of the sample, with the resulting expansion detected by a pressure-sensitive element -eg, a capacitance microphone. Despite an only moderate sensitivity of around 10'°atoms/cm3 3 (Koch and Lahmann, 1978), the method is important in molecular spectroscopy, where often many nonradiative decay processes make techniques such as fluorescence spectroscopy very difficult.…”

Section: Absorption Methodsmentioning

confidence: 99%

Materials analysis using laser-based spectroscopic techniques

Goddard

1991

Transactions of the Institute of Measurement and Control

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In this paper several laser-based spectroscopic methods capable of detecting low concentrations of a particular element are described, with particular emphasis on the contrasting techniques of Laser-Induced Breakdown Spectroscopy (LIBS), and Resonance Ionisation Mass Spectroscopy (RIMS). Simple mathematical treatments, based on thermodynamic considerations and rate equation models, are given for both systems, allowing semiquantitative analysis from the magnitudes of observed signals. Experimental results are presented for both methods. For LIBS these include the determination of the concentration of alloy constituents, the detection of surface contaminants and the use of measured line intensities to calculate electron temperatures in laserproduced plasmas. For RIMS, detection of the geologically important element rhenium (Re) was accomplished in the gas phase at a level of 4 x 10 8 atoms/cm 3 , and the relative proportions of the stable isotopes 185 Re and 187 Re were measured with the use of a quadrupole mass filter. In addition, an optogalvanic system is described, which was used to calibrate the wavelength of the RIMS resonance to an accuracy of 0.013 nm.

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Section: Absorption Methodsmentioning

confidence: 99%

Materials analysis using laser-based spectroscopic techniques

Goddard

1991

Transactions of the Institute of Measurement and Control

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“…The shape of the PA cell is thus of prime importance and many different designs have been proposed [3 and references therein]. To improve the PA sensor sensitivity acoustically resonant PA [4][5][6][7][8][9][10][11], multipass [12,13], intracavity [14,15] and parallel cells [16] have been developed. Synchronous noise generated by the light absorption at the cell windows is a sensitivity limiting factor that has been minimized by the development of acoustic baffles [17], ''windowless" [18], differential [19,20] and quartz enhanced [21] PA cells.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous dual-frequency excitation of a resonant photoacoustic cell

Rey

Sigrist

2008

Infrared Physics & Technology

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“…Furthermore, PA cells for multipass (Koch & Lahmann, 1978;Nägele & Sigrist, 2000) or intracavity operation (Fung & Lin, 1986;Harren et al, 1990a) were designed. The effect of window heating in the amplitude modulation schemes has been minimized by introducing acoustic baffles (Dewey, 1977), developing windowless cells (Gerlach & Amer, 1980;Miklos & Lörincz, 1989;Angeli et al, 1992), or using tunable air columns (Bijnen et al, 1996).…”

Section: Photoacoustic Cellmentioning

confidence: 99%