Acoustic detection module (ADM) is a stainless steell cell designed to be easily integrated in a full detection system based on quartz-enhanced photoacoustic spectroscopy (QEPAS).

Inside the ADM a quartz tuning fork (QTF) can be accommodated and coupled with two millimetric resonator tubes, optimized to amplify the generated photoacoustic waves and match the resonance properties of the selected QTF.

The acoustic signal is transduced by the QTF and converted into an electric current due to the piezoelectric properties of quartz. Then, the current signal is converted into a voltage signal by means of a custom designed transimpedence preamplifier with high gain.

Laser sources of different types can be focused inside the ADM passing through two wedged windows with diameter Ø1/2" with antireflection coating optimized for the 200 nm - 11 µm range. The windows are interchangeable to explore different spectral range.

The ADM module is equipped with gas line inlet/outlet allowing rapid gas exchange in the cell. As standard, two Hylok 6 mm standard fittings are used to connect the ADM to the gas line.

All the main constituents of the ADM can be customized and replaced, including:

• QTF
• resonator tubes
• Input/output windows

Custom design for specific applications are available upon request.