Analytical optoacoustic spectrometry. Part I. Instrument assembly and performance characteristics

Abstract

A simple single-beam spectrometer suitable for the study of optoacoustic spectra from small solid samples is described and the design of a suitable sample cell is reported. The performance characteristics of the spectrometer have been evaluated using different types of sample. A preliminary assessment of the predicted advantages of optoacoustic spectrometry over conventional techniques of ultravioletvisible absorption and reflectance spectrometry for solid samples has been made.

Induction kinetics of heat emission before and after photoinhibition in cotyledons of Raphanus sativus

“…This is due to the damping of heat emission inside the sample, which influences the thermal active layer, the maximum depth of the sample from where heat emission is sensed. With increasing modulation frequency of the excitation light the thermal active layer becomes shorter (Adams et al 1976). Because of this depth profile effect (Rosencwaig and Gersho 1976) the decrease is especially pronounced for a leaf.…”

Analytical Aspects of Photoacoustic Spectroscopy

“…35 ' 60 ' 61 Bennett and Forman," Kerr, 63 and Afromowitz et al 64 have investigated various aspects of the process, measured absorption coefficients, and derived theoretical models to account for their results. However, the two approaches we have found most useful have been those of Aamodt et al 33 ' 65 and Rosencwaigand Gersho.…”

Photoacoustic spectroscopy (PAS) and its application in photosynthesis research

“…The height of the photacoustic signal is determined by the characteristics of the spectrometer and of the sample [3,31,35]. To receive a high signal] noise ratio the following parameters are of importance: instrumentation:…”