Low-cost Spectroscopy: Experiments in Various Spectral Ranges

Abstract

Teaching the basic principles of molecular spectroscopic techniques on an experimental basis is often a particular challenge due to the relatively high cost of the required experimental equipment. The present contribution therefore offers an experimentally-based introduction into the field of spectroscopy using low-cost devices for practical courses at undergraduate level and for chemistry lessons in high schools. Using low-cost devices are also useful for schools in developing countries or poorly-funded school systems. Several experiments, specifically tailored for chemistry lessons, are developed, aiming to provide a close relation to the everyday life experience of students. Initially, a simple spectrometer working within the visible range of light is constructed by the student themselves. This low-cost dispersive spectrometer is employed for quantitative food analyses. In a second step, an introduction to spectroscopy in the near-infrared range is given using an example based on the identification of plastics. On this basis, a model experiment using a self-constructed apparatus for plastic waste separation in miniature was developed. Finally, experiments in the mid-infrared range are presented. They introduce into the functionality of a Michelson interferometer and demonstrate the use of low-cost carbon dioxide sensors. Using this strategy, students gain easier access to an understanding of radiation-matter interaction.