Use of Carbon Black as a Reference Material in Photoacoustic Spectroscopy

Abstract
Variations in the visible photoacoustic spectra of carbon black samples from different sources have been observed. These variations indicate that some care must be exercised in the choice of a particular carbon black for use as a reference (perfectly absorbing) material in photoacoustic spectroscopy, particularly when quantitative information from weakly absorbing samples is desired. Of the carbon black samples investigated, Norit A decolorizing carbon most closely approximates a perfect absorbing material.