摘要:
A fire alarm system comprises a first light emitting device (11), a first polarizing filter (31), a first light receiving device (21), a second light emitting device (12), a second polarizing filter (32), and a second light receiving device (22). With the above arrangement, the amount of the parallel polarized component to the scattering plane as well as the amount of the perpendicular polarized component to the scattering plane is detected. The ratio between these amounts of light has a correlation with the type of smoke. A calculation section (4) calculates this ratio from the outputs of the light receiving devices (21, 22). A decision section (6) compares the above-described ratio with a reference value which has been preset according to the type of smoke to be detected, whereby the judgement of whether there is a fire or not is performed depending on the type of smoke. Thus, the detection of a fire can be performed from the light scattered by smoke taking into account the type of smoke.
摘要:
A fire alarm system which radiates light towards a smoke detecting space. Scattered light resulting from smoke that may exist in the smoke detecting space is judged by a receiver with respect to the type of smoke that may prevail in the space. The presence of a fire is judged by comparing the light that has been received with a set threshold level. The threshold level is set to different levels in accordance with the type of smoke detected.
摘要:
To provide a heat detector in which thermal responsiveness of a heat detecting unit such as a ceramic element is improved.A heat detector 1 includes a ceramic element 10 accommodated in a sensing-device main body, and measures a temperature in a monitoring area based on a dielectric constant of the ceramic element 10. The Curie point temperature of the ceramic element 10 is set in a predetermined sensitive temperature range.
摘要:
In a light scattering smoke sensor of the present invention, a first diaphragm portion is disposed just aheat of a light receiving device, and a second diaphragm portion is disposed ahead of the first diaphragm portion. A gap between the first and second diaphragm portion is a smoke introducing portion which introduces smoke to a smoke detecting space via a gap between labyrinth members and the second diaphragm portion.
摘要:
A scattered light type smoke detector wherein a light source and a photo-cell are so disposed that light from the light source does not directly enter the photo-cell and the photo-cell is adapted to receive light from the light source scattered by intervening smoke to detect the presence of smoke. The photo-cell is accommodated in a cylindrical recess formed in a smoke detecting holder. The inner face of the cylindrical recess and the surface of the smoke detecting holder extending along the optical axis of the photo-cell has light traps formed in sawteeth configuration in section for reflecting light other than the scattered light to be detected into a direction not towards the photo-cell.
摘要:
An object is to build a protective structure which can protect a ferroelectric material from a surrounding environment when the ferroelectric material is used as a heat detecting element of a heat detector, thereby enhancing the reliability of the heat detector.A heat detector includes a heat detecting unit 11 that senses heat in a monitoring area, and a casing 81 that holds the heat detecting unit 11, and the heat detecting unit is held by the casing 11 via a laminating portion 60 which serves to protect the heat detecting unit 11.
摘要:
A light scattering type smoke sensor includes a sensor body, light-emitter for emitting light toward an open smoke-sensing space and outputting a light-received signal according to the amount of scattering light received, and a fire judging unit for judging whether fire occurs or not on the basis of the amount of received light determined on the basis of the outputted light-received signal.
摘要:
A smoke detector in which a plurality of labyrinth members are disposed on an upper wall in a standing position. In an area surrounded by the labyrinth members, a smoke detecting chamber is formed. A light emitting device and a light detecting device are disposed in such a manner that their optical axes intersect each other at the center of the smoke detecting chamber. In order for the visual field of the light detecting device with respect to the smoke detecting chamber to be restricted to the front area thereof, the labyrinth member which cross the optical axis of the light emitting device is formed so as to be longer than the other labyrinth members, and a gap is formed between the front end of the long labyrinth member and a light shielding plate for preventing the light emitted by the light emitting device from directly reaching the light detecting device. Therefore, the zero-point level of the detection output for light scattered by smoke is lowered to enhance the reliability and effectiveness of the smoke detector.
摘要:
A fire alarm system of the present invention is adapted to compute an approximation equation based on the detection data from a detector or detectors such about a smoke density, a temperature, a gas concentration, etc. and predictively determine a fire based on the approximation equation. The system including computing section for computing an approximation equation approximating a change in the physical phenomenon related to the occurrence of a fire which is output from the detector or detectors, sequentially sampled and stored and for computing a future value of the phenomenon estimated from the approximation by using a predetermined number of the data stored in a storing section. The future vale is compared with a data value preliminarily set in association with the fire alarming and an alarm is generated when the relation therebetween is not within a predetermined range.
摘要:
A light scattering type smoke sensor includes a sensor body, light-emitter for emitting light toward an open smoke-sensing space and outputting a light-received signal according to the amount of scattering light received, and a fire judging unit for judging whether fire occurs or not on the basis of the amount of received light determined on the basis of the outputted light-received signal.