Gas Sensing using tunable mid-IR lasers and Photoacoustic spectroscopy (PAS)

Although the technique of Photo-Acoustic Spectroscopy (PAS) has been around for over a century, the method has been somewhat limited in sensitivity due to the microphone and laser technology. In recent years improvements have been made on both these fronts which mean that PAS is now viewed as an advanced method for very sensitive trace gas analysis and detection.