Operation of ISTA smoke detectors under conditions of high dustiness

At Ista-Archive, we have developed models of optoelectronic smoke detector intended for use in different constructions ‒ residential, commercial and especially in industrial and infrastructure constructions.

Smoke detectors installed in manufucturing areas or in transport enterprises usually operate under conditions of high dust concentration. Dust particles get inside the optical chamber, accumulate on its inner surfaces and cause unwanted additional light scattering. A large dust particle or a "dust storm" inside the sensing camera created by a random sharp air flow cause a detector false alarm. Sensitivity drift is another problem caused by dust accumulation.

Keeping in mind these points, our specialists persistently worked on the design of the smoke detector enclosure. It was important to achieve two results: to ensure sufficient air flow in the sensing chamber and to prevent the ingress of a large amount of dust. Finding a solution, they consulted engineers from other fields, in particular aircraft designers. In order to maintain a constant level of response threshold value with time, an internal sensor signal processing algorithm has been developed that includes a sensitivity drift compensation. This processing algorithm gives good results even when the optical chamber becomes very dirty.

Our point optical smoke detectors have been installed in several Kyiv metro stations. They protect traction substations, cable tunnels, sub-platform space. Detectors operate in difficult conditions, because they are located very close to tracks where a lot of natural dust and brake pad dust is accumulated. In addition, in underground tunnels, the humidity level is high.
Moreover, the urban metro system is an enterprise with a high level of industrial electromagnetic interference (EMI). EMI disturbs the proper functioning of electrical circuits, so it is dangerous for a fire detection system operation. Our specialists used the latest electronic components and advanced circuit solutions to increase EMI immunity, provide good technical characteristics and minimize nuisance fire alarms of smoke detectors.

Smoke detectors developed and manufactured by Ista-Archive have proven themselves reliable devices. For example, they have been operating for several years in difficult conditions of Kyiv metro system without failures or the need for cleaning.

Pictures below show the state of a smoke detector chamber after four years of operating under the conditions described above. Despite a thick layer of dust on the chamber surface, the detector worked without loss of sensitivity.

Our fire detectors have passed certification tests and received certificates of conformity.