A study of laser-acoustic air pollution monitors

Simultaneous determination of mixtures in liquid by laser-induced photoacoustic spectroscopy

“…Dixon et al ( 3) have measured photoacoustic spectra of forbidden transitions in some unstable gaseous sulfur compounds with a tunable CW dye laser. Recently, Lahmann et al (4) and the present authors (5) have successfully applied this method to the ultra trace analysis of liquid samples with an argon ion laser. Laser-induced photoacoustic spectroscopy (LIPAS) has brought a considerable improvement in the detection limit in comparison with conventional absorption spectrometry.…”

Determination of nitrogen dioxide by visible photoacoustic spectroscopy

“…uv The conservation of the number of molecules is written as #i = *oiW0 -(^ior k10')Ni (4) or IVi = VWr ~(&oia + k10* + kwc)Nl (4a) where &01a and kwT are the radiative rate constants. The &01a part consists of only the absorption term ( ß0i) while the kwc part has two separate terms describing stimulated (pj310) and spontaneous emission (k^f).…”

“…The resurgent interest in photoacoustiic spectroscopy fostered by the development of versatile lasers was rapidly directed toward practical applications such as the quantitative detection of atmospheric pollutants (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14), particularly N02…”

“…The increased, efficiency of photoacoustic detection at higher pressures makes it well-suited for applications such as atmospheric pollution monitoring. Most of the initial work in the area was performed by using infrared laser excitation (1)(2)(3)(4)(5). For many atmospheric pollutants, however, photoacoustic spectroscopy initiated by excitation in the visible and ultraviolet regions provides significant advantages over excitation in the infrared region.…”

Optoacoustic and optogalvanic spectroscopy

“…In this short discussion of optoacoustic and optogalvanic spectroscopy many important applications of the techniques have had to be omitted. Some of the important applications that I have not been able to discuss are the use of optoacoustic detection in the following: phase transitions in solids (Pichon et al 1977;Florian et al 1978; Korpium quantum efficiencies of optical processes (Murphy et al 1977;Quimby & Yen 1978Powell et al 1980), time-resolved studies (Mandelis 1980;Migliori et al 1980), photothermal spectroscopy Boccara et al 1980;Brueck et al 1980), electron spin reson ance (Coufal 1981;Netzelmann et al 1982;Melcher 1980Melcher ), ferroma 1979Evora et al 1980;Melcher 1980), photoacoustic microscopy (Pouch 1980), laser e measurements (Shaw 1981), trace-element detection (Koch & Lahaman 1978, Rosengren et al 1974Perlmutter et al 1979; Shtrikman et al materials (Marinero & Stuke 19796), studies of surface plasmons in metals (Inagaki 1982) and absolute absorption-coefficient measurements (Wetsel & McDonald 19775 Teng & Royce 1980).…”