RU92011358A - SMOKE DETECTOR - Google Patents

Claims (1)

The smoke detector relates to fire alarm systems, in particular, to smoke detector designs designed for use in optoelectronic fire detectors to detect fires, accompanied by the appearance of smoke in enclosed spaces of various buildings and structures by detecting optical radiation scattered by particles. The smoke sensor contains a housing inside of which there is an emitter with a focusing lens, a photodetector, a reflector made in the form of a hollow truncated cone, the base of which is an elliptical surface, its axis is aligned with the axis of the photodetector and is located at an angle full registration of the radiation directed forward, and the angle between the elliptical plane of the conical reflector and the optical axis of the radiator is equal to g and is calculated by the formula

d is the diameter of the focusing lens; f is the focal length of the lens; a is the distance from the radiation source to the focusing lens, while the focusing lens is installed at the site of a small circular cross section. The sensor is equipped with a spherical reflector, the concave side of which faces the conical reflector, and its focus is in the center of the elliptical section of the conical reflector. The distance from the optical axis to the plane of the base of the spherical reflector should not be less than half the diameter of the focusing lens. The design of the smoke sensor is effective in use, technologically advanced in manufacturing, provides an increase in the range of angles of registration of the scattered radiation due to the presence of a spherical reflector, and the focusing of radiation using a focusing lens and a specific location of the conical reflector made it possible to eliminate false alarms. All this allows to significantly increase the sensitivity of the smoke sensor (0.03 - 0.05 dB / m) regardless of the color of the smoke.