Silent Knight 30-3003 Optical Smoke Detect Explosion Proof

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Our Price : $5,857.00

Product Code: 30-3003

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Description

Specifications

The photoelectric smoke detector uses a solid state infrared emitting diode (IRED) and a light sensing photovoltaic cell arranged in a labyrinth assembly. The labyrinth permits free access to smoke but restricts external light. Because of its critical function to the operation of the detector, each IRED is selected with extreme care and is subjected to rigorous pre-production testing to ensure long-term reliability and performance. During normal operation (no smoke), the detector samples the air approximately every four seconds for a period of less than one millisecond. The photovoltaic smoke cell, which is placed at an angle to the pulsed invisible light source , is sensitive to the infrared light in the specified frequency emitted by the IRED light source and is designed to receive a signal only when the pulsed IRED source is activated. See Figure 1. When smoke enters the chamber, the light from the IRED reflects off the smoke particles and reaches the photovoltaic smoke cell. When the amount of light reflected by smoke reaches the factory set threshold level, the smoke alarm circuit is actuated. The detector will respond to a slow smoldering fire when smoke in the chamber reaches the pre-set sensitivity setting, typically 2.3%. If a fast burning fire should occur, including fires in flammable liquids and other materials such as plastics that generate black smoke, the abnormally rapid movement of smoke into the detection chamber is sensed by a special rate compensating circuit. An increase in smoke within the detection chamber that exceeds a pre-set rate causes the rate compensation circuit to increase the intensity of the light source, which increases detector sensitivity. If the smoke continues to build at this rate, an amplifier circuit is triggered and the unit generates an alarm. If not, the detector reverts to normal sensitivity.