Photoacoustic
Cell Design
The
designing of the photoacoustic cell is really critical to get a very good signal
to noise ratio. All theoretical and experimental studies predict that for a
constant light absorption, the amplitude of the photoacoustic signal reaching
the microphone depends on the size of the cell and in general increases as cell
dimensions are reduced. However, one must not minimize this to a point that the
acoustic signal produced at the sample suffers appreciable dissipation to the
cell window and walls before reaching the microphone. Proper acoustic isolation
from outside world and microphone configuration is also critical. Most
importantly, the sample to be studied plays a significant role when designing a
photoacoustic cell. Taking these considerations in mind, several cell
configurations are developed in ISP labs. Please see the cross-sectional view of
some of the important cell designsigns.
