The Hekatron ORS 142 is an optical smoke switch that operates on the light scattering principle. Inside the sensing chamber, a light source and light sensor are arranged so that the light does not fall on the light sensor. Only when airborne particles enter the chamber, the light is scattered onto the light sensor.
The electronic circuitry of the ORS 142 also monitors the smoke detection system
for slight contamination (dust and dirt build-up), heavy contamination and faults (sensing chamber failure).
The LED provides an optical indication of the operating status of the ORS 142 5000552-0301. A long-term compensation function automatically maintains a constant difference between the quiescent signal and the alarm threshold, until a set limit indicating heavy contamination is reached. A relay contact opens in the alarm condition or on power failure.