GDA2

The most sophisticated device GDA2 from the company AirSense from Germany at this moment incoroporates these detection techniques:

• IMS (Ion Mobility Spectrometer) - a special kind of mass spectrometry. This type of spectrometer can only be manufactured in small sizes.
• PID (Photon Ionisation Detector) - photoionization detectors
• Electrochemical cells
• Specific detectors

You can find a brief description of the principles of individual detection techniques and their practicability for mobile detection of toxic industrial and combat chemicals in the literature listed below [1]. GDA2 analyzer processes signals from all the detectors at once. To increase the selectivity, it can also use statistical software, that evaluates information from multiple detectors. Thanks to the developments in microelectronics and electromechanical elements miniaturization, these instruments achieve reasonable weight (cca 4 - 5 kg) and are constructed for use in difficult field conditions. The operation and maintenance of the analyzer are also adapted for field conditions, for example for the use by fire fighter squads. Examples of the range of analyzed industrial compounds, type of detector used and concentration limits are shown by table 1

[1] „Guide for the selection of Chemical Agent and Toxic Industrial Materiál, Detection Equipment for Emergency First Responders, Volume I  vydal National Institute of Standards and Technology 2005

Further information on manufacturers website.