Photoacoustic infrared spectroscopy differs from traditional infrared spectroscopy in one important way: in its most common implementation, a microphone is used to detect acoustic waves that result from absorption of infrared radiation by a sample. In other words, no optical detector is required to quantify the amount of incident radiation taken up by the sample. This gas-microphone method is one of a series of photoacoustic and photothermal techniques now being used for characterization and analysis of solids, liquids, and gases. Photoacoustic Infrared Spectroscopy represents the most comprehensive resource on this important, emerging technique. Kirk Michaelian℗s trenchant study serves as both a text and reference for a broad community of academic and industrial scientists conducting extensive research and applications in photoacoustic infrared spectroscopy. Chapters include: Evolution of Photoacoustic Infrared Spectroscopy Experimental Methods Depth Profiling Numerical Methods Applications of Photoacoustic Infrared Spectroscopy Quantitative Analysis Special TopicsPhysicists, chemists, and spectroscopists in both academic and industrial laboratories, polymer and organic chemists, analysts in industry, forensic and government laboratories, and materials scientists will find Photoacoustic Infrared Spectroscopy to be a vital resource.