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In recent years, several manufactures of IR imaging devices have launched commercial models applicable to a wide
range of chemical species. These cameras are rugged and sufficiently sensitive to detect low concentrations of toxic and
combustible gases. Bertin Technologies, specialized in the design and supply of innovating systems for industry, defense
and health, has developed a stand-off gas imaging system using a multi-spectral infrared imaging technology. With this
system, the gas cloud size, localization and evolution can be displayed in real time.
This technology was developed several years ago in partnership with the CEB, a French MoD CBRN organization. The
goal was to meet the need for early warning caused by a chemical threat. With a night & day efficiency of up to 5 km,
this process is able to detect Chemical Warfare Agents (CWA), critical Toxic Industrial Compounds (TIC) and also
flammable gases.
The system has been adapted to detect industrial spillage, using off-the-shelf uncooled infrared cameras, allowing 24/7
surveillance without costly frequent maintenance. The changes brought to the system are in compliance with Military
Specifications (MS) and primarily focus on the signal processing improving the classification of the detected products
and on the simplification of the Human Machine Interface (HMI).
Second Sight MS is the only mass produced, passive stand-off CWA imaging system with a wide angle (up to 60°)
already used by several regular armies around the world.
This paper examines this IR gas imager performance when exposed to several CWA, TIC and simulant compounds.
First, we will describe the Second Sight MS system. The theory of gas detection, visualization and classification
functions has already been described elsewhere, so we will just summarize it here. We will then present the main topic
of this paper which is the results of the tests done in laboratory on live agents and in open field on simulant. The
sensitivity threshold of the camera measured in laboratory, on some CWA (G, H agents...) and TIC (ammonia, sulfur
dioxide...) will be given. The result of the detection and visualization of a gas cloud in open field testing for some
simulants (DMMP, SF6) at a far distance will be also shown.
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