The Infrared Photoacoustic Spectroscopy (IR-PAS) technique is hampered in many instances in its applications by the low signal-to-noise (S/N) ratio, which is generally due to the environmental noise present around the equipment. One method of S/N ratio enhancement is to acoustically isolate the detector from outside noise. This can be accomplished by placing the detector in a chamber. This note will describe such a chamber and its effect on the S/N ratio.
Parviz Mahmoodi, Richard W. Duerst, and Rudd A. Meiklejohn, "Effect of Acoustic Isolation Chamber on the Signal-to-Noise Ratio in Infrared Photoacoustic Spectroscopy," Appl. Spectrosc. 38, 437-438 (1984)