Quantitative dust test technology for point-type smoke detectors: Using in aircraft cargo compartments

In airborne applications false alarms can be very costly, as they may force a pilot to an emergency landing at the next airport. Dust is the major source of false alarms in cargo compartment applications. The dust suspending in air is the main reason of trigging false alarm of smoke detectors. Long time deposition of dust in the chamber of a smoke detector may cause the drift of the threshold and cause false alarm or missing alarm. Also the increase of dust concentration in air in a short time may also cause false alarm of smoke detector. The ability of anti-dust pollution of a smoke detector is a key factor for the reliability of a smoke detector. A dust test equipment for quantitative research of dust pollution has been designed and built up at Shenyang Fire Research Institute. The main body of the equipment consists of dust test chamber, dust concentration meter, optical smoke density meter, dust generator and computer. Two patterns of tests have been carrying out for transient disturbance and long-term deposit effect respectively. From the result criteria, we can tell the differences between different smoke detectors in their resistance to dust interference.