Vertical Double-Pass Multiple Reflection Element for Internal Reflection Spectroscopy

A vertical double-pass internal reflection element for internal reflection spectroscopy is described which can be dipped into vessels containing liquids or powders to record their spectra. It has the advantage over the horizontal double-pass internal reflection element in that no additional optical components are required to reorient the spectrometer slit image. Photographs are presented of internal reflection elements showing the actual paths of the light beams outside and inside the internal reflection elements.