3. ASD535
3.1. Summary
ASD535 was predicted by the Secrition Company, the subsidiary of Securitas Group in Switzerland and the most
advanced and integrated fire detection manufacturers in European.
Through the aspirator pump, ASD inhales the sample air into the detectors for analysis with an active method. Since the
detector uses a high-power infrared LED light source, it is 1000 times more sensitive than the ordinary smoke detectors. As
a result, it can detect the fire promptly which allow the fire brigade to deal with the fire before it has time to breaks out,
protecting the safety of people's life and property.
ASD can detect the fire at the earliest stage. Fig.1 shows the evolution of a fire. Traditional fire alarm installations
usually detect the fire and trigger an alarm at the visible smoke stage when the fire had caused huge economic losses. Before
the visible smoke stage, an invisible smoke stage was gone through. For ASD 535, smoke changes can be reliably detected
at a minimum level of 0.002% obscuration per meter – a level invisible to the human eye. So, it can detect smoke in good
time and nip the fire in the bud.