A specific multi-channel photon-counting unit for air-pollution measurement

A photon-counting system based on an appropriate microcontroller has been developed. This system controls, acquires, processes and stores the data from a high-resolution multi-channel gas analyzer and provides accurate photon-counting measurements using suitable Photomultiplier Tubes (PMTs) as detectors of the Raman scattering signals. The implemented system ensures low power consumption (90 W for the overall system), low cost, increased reliability and high sensitivity. Also the entire unit allows auto-calibration and drift compensation. Finally, the present photon-counting system can be used in a broad field of applications, in medical electronics (e.g. confocal microscopy), air pollution optical measurements, laser sounding of the atmosphere, and electrooptical systems, provided that PMTs are used in the pulse-counting mode.