PA101 - Photoacoustic low volume gas analysis module

The PA101 photoacoustic gas analysis module is an FTIR accessory that fits into the sample compartment of common laboratory FTIR instruments.

The PA101 allows gas analysis from very low gas volume using optical path length of only few centimeters with the sensitivity of a much longer gas cell used in the conventional transmission measurement. Therefore, the photoacoustic signal is highly linear in a very wide dynamic range and a very small amount of gas is required for the reliable analysis.

The photoacoustic signal is generated only from the absorption, and therefore, drifts in the alignment of the interferometer optics have only a small effect to the gas spectra. Due to the low drift and no need for background calibration, the PA101 is higly suitable e.g. to FTIR headspace analysis.

PA101 photoacoustic gas analysis module consists of:

Stainless steel Gas cell with inlet and outlet valves
Optical cantilever microphone with built-in laser interferometer
Automatic gas exchange module
Digital Signal Processing module
Particle filter
Power supply (+12 VDC)
Cables to connect the modules and to connect to the FTIR instrument
User manual
Storage case

Features and speciﬁcations:

Detection limits gas depended, typically in the sub-ppm region
Total internal gas volume: Approx. 30 ml
Gold coated gas cell
Patented ultra-sensitive optical microphone based on a
MEMS cantilever sensor coupled with a laser interferometer
to measure microscopic movement of the cantilever
sensor
Minimum detectable pressure variation in the sample cell: 7.7 x 10-7 Pa/√Hz (RMS)
Analog interface: BNC cable to detector input on the
Analog output: +/- 2.5 VDC interferogram signal
Recommended FTIR scan rate: 2.5 kHz or less (HeNe frequency)
Weigth: cell module 2.3 kg, DSP module 0.7 kg