Abstract

Sample position dependence effect in photoacoustic (PA) spectrometry has been reported by several scientists. This effect must be taken into account in a PA application that requires a quantitative theoretical treatment. In this work, we experimentally investigated PA signal magnitude varying with sample-to-window distance in an MTEC Model 300 Photoacoustic Detector, which has a fixed empty (gas) volume in addition to the sample-to-window-distance-dependent gas volume. An operative method was introduced to obtain the coefficient, which considered the sample-to-window distance and the additional gas volume. With this coefficient, the one-dimensional PA model, developed by Aamodt, Murphy, and Parker, can be employed to quantitatively process PA experimental data, no matter what the sample-to-window distance is. Quantitative measurements of thermal effusivities of two samples were performed to prove this effective normalization method.

Photoacoustic spectroscopy with condensed samples

John F. McClelland and Richard N. Kniseley
Appl. Opt. 15(11) 2658-2663 (1976)

Relaxation time measurements in frequency and time-domain photoacoustic spectroscopy of condensed phases

A. Mandelis and B. S. H. Royce
J. Opt. Soc. Am. 70(5) 474-480 (1980)

Photoacoustic effect in a flowing liquid

Richard S. Quimby and Andrew I. Sheinis
Appl. Opt. 26(2) 363-371 (1987)

High temperature Fourier transform photoacoustic spectroscopy: sample emission effects

S. McGovern, B. S. H. Royce, and J. Benziger
Appl. Opt. 24(10) 1512-1514 (1985)

Extended Helmholtz resonator in low-temperature photoacoustic spectroscopy

J. Pelzl, K. Klein, and O. Nordhaus
Appl. Opt. 21(1) 94-99 (1982)