Construction of a Low Cost Photoacoustic Spectrometer for Characterization of Materials

Abstract

During the past few years, another optical technique has been developed to study those materials, which cannot be studied, by the conventional transmission or reflection techniques. The present technique called Photoacoustic spectroscopy or PAS is different from the conventional techniques chiefly in that the interaction of the incident energy of the photons with the materials under investigation is studied not through subsequent detection and analysis of some of the photons, but rather through a direct measure of the energy absorbed by the material. The aim of this presentation is to highlight the construction of a simple Photoacoustic spectrometer which can easily be constructed even in high school and college laboratories with the available low cost but efficient components and use it for characterization of solid (opaque or transparent), liquid and gas samples under investigations. The essential parts of the photoacoustic spectrometer designed in the laboratory (MADURAI – PA SPECTROMETER), consists of three main components.The total cost comes around 900 Euros. It is an affordable cost for researchers working with paucity of funds and facilities and many constraints especially in the developing countries. In the next few years we aim to study material characterization using MADURAI –PA SPECTROMETER.

Photoacoustic spectroscopy for analytical measurements

“…How simple a PA setup can be to build has been demonstrated by Nosaka et al [113], who employed Xelamp/monochromator combination for excitation, and a smallsize piezo detector, which is immersed directly into the sample liquid. Probably the most straightforward instrument suitable for PA spectroscopy was presented by Rajan et al for the analysis of solids, liquids and gases [114]. Instead of the monochromator, they use filters, illuminating a simple funnel-shaped PA cell.…”