The detector comprises of a Transmitter and Receiver contained within one enclosure.
The Transmitter emits an invisible infrared light beam that is reflected via a prism(s) mounted directly opposite and with a clear line of sight.The reflected IR light is detected by the Receiver and is analysed.Smoke in the beam path will reduce the received IR light proportionally to the density of the smoke.The detector analyses this attenuation, or obs curation and acts accordingly
In some gas detectors, the point detector operates on a short fixed path (30 to 150 mm) between the IR light source and the light detector, assuming uniform concentration along this path. IR light is passed through a sample of the gas/vapor, and received at the sensor(s).
The active sensor is set in the absorption band of the gas being monitored, while the reference sensor is not. The ratio of the wavelengths is compared to determine if the gas/vapor is present.
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