Benefits at a glance
Sensitivity is basically not dependent on the optical path length
Major advantage of the photoacoustic effect is the fact that sensitivity is basically not dependent on the optical path length. This allows high sensitivity from short absorption path length and highly linear concentration response over a wide dynamic measurement range from very low sample volumes.
No interfering signal and extremely accurate results
The absorption is measured directly and not in relation to the background. Therefore the PAS is one of the most sensitive methods for the detection of gases and often used in trace-gas analysis.
Low sample volume and small cell size
The small size of the PAS cells enables the measurement of very small gas volumes. In contrast to conventional methods, the sample volume can be reduced drastically.
Great price advantage
Another advantage is that the PAS is generally cheaper than other gas analysis methods. The reason for this are the microphones which are less expensive than (infrared-)detectors.
Low amount of drift
The response of the microphone is extremely stable. Therefore the drift is very low and a calibration is seldom needed.