Mesurer la qualité de l’air dans les stades

Security Aspects of Large Events
Whether preparing for political summits or international sporting events, many aspects must be considered: these include testing the air for harmful gases. This is carried out via so-called passive open-path FTIR, which was originally developed for military applications (e.g., the localization and characterization of poisonous gas clouds). Passive systems are characterized by the fact that they do not require an external light source or reflection optics for these measurements. This allows for continuous 24/7 and 360° monitoring.

In Fourier transformation infrared (FTIR) spectrometers, a laser provides the frequency standard. In the beginning, HeNe lasers were primarily used for this purpose; however, they were phased out as part of the miniaturization process by single-mode vertical cavity surface-emitting lasers (SM-VCSELs). This led to the development of compact systems for use in civil applications as well: This allows fire departments to better assess large fires, hazard prevention teams to respond to possible poisonous gas attacks early on and send out warnings or evacuate.

One example of a “scanning infrared gas visualization system” is the SIGIS 2 from Bruker, which was christened at the start of the World Cup in Germany in 2006. Luckily, there have not been any serious incidents; however, this technology has still been tested many times: for example, at public viewing events in Stuttgart, it was possible to localize alcohol clouds [3]. These systems are used surprisingly often; in fact, even Brazil ordered units prior to the Games.