摘要:
An ionization-type smoke detector having inner and outer ionization chambers, a radioactive source to ionize the air within the inner and outer ionization chambers and a printed board to mount electrical circuits for detecting electrical potential at the connecting portion between both chambers is made to be relatively thin by arranging the inner, intermediate and outer electrodes so that they are respectively vertically mounted to the printed board while being transversally spaced apart from each other.
摘要:
An alarm and control system for semiconductor factories or the like includes, at locations where poisonous and inflammable gases such as silane gas are used as in the manufacturing process of semiconductors, gas detectors to detect the leakage of the treatment gases and fire detectors to detect products of combustion of the treatment gases, and these detectors are adapted to cause, upon any changes in the output state of either of them, an alarm to issue and a protection device such as a fire distinguishing device as well as the manufacturing process to be controlled.
摘要:
A foam extinguishing system in which a foam generating net is provided at the front of a chamber, and foam nozzles and a gas discharge nozzle are provided at the rear of the chamber is disclosed wherein in order to lengthen the flying distance and suspension time of the non-combustible gas solution discharged from the gas discharge nozzle a deflector is provided in front of the nozzle to reflect and disperse a non-combustible gas solution discharged from the nozzle rearwards or sideways from the rear. The gas discharge nozzle provided with the deflector may be also located in such a position that the non-flammable gas solution reflected and dispersed by the deflector does not disturb the discharge pattern of a foam solution from the foam nozzles and that the non-combustible gas is pushed forward by an air flow generated in the air by a negative pressure.
摘要:
An ionization type smoke detector for fire alarm comprises an inner ionization chamber (a) defined by an inner electrode (6) and an intermediate electrode (8), an outer ionization chamber (b) defined by the intermediate electrode (8) and an outer electrode (11), and a single radioactive source (3) for ionizing air present in both ionization chambers (a; b). In this type of an ionization type smoke detector, for the purpose of protecting the radioactive source from contamination on one hand and assuring on the other hand that smoke positively supplied to the smoke detector for operational testing is promptly dispelled from the detector upon completion of the test so that the detector can be rapidly restored to the normal operating state, the radioactive source (3) is enclosed by the inner electrode (6), a substrate (1) and an annular wall (2), while the intermediate electrode (8) is supported by a plurality of studs (9) extending from the substrate (1). Openings (7; 10) are provided in the inner electrode (6) and the intermediate electrode (8), respectively, whereby the inner and outer ionization chambers (a; b) are irradiated with radioactive ray emitted by the radioactive source (3) by way of the openings (7; 10).
摘要:
A light extinction type smoke detector which uses simple pulsed light or modulation pulsed light to reduce energy consumption, and precisely discriminates smoke generated by fire from extraneous interruption of the light beam from the light source to the photoelectric element to prevent a false alarm.
摘要:
This invention relates to an element which can detect selectively carbon monoxide from other reducing gases contained in air. The element has a sensitive response to carbon monoxide at a comparatively low temperature and not to other reducing gases. The element has a composition comprising stannic oxide as a base material, platinum black as a catalyst and, if necessary, clay, ferric oxide or glassy substances as a sintering agent. A starting substance for stannic oxide may be stannic oxide itself or any stannic salt which is changed into stannic oxide by baking. A starting substance for platinum black may be platinum black itself or any platinum salt which is changed into platinum black by baking. The above starting substances are thoroughly mixed and baked to form a detecting element. The element may be used as a lump by itself, but it is convenient that it is used as a film of the element baked on a heat-resisting insulating material such as an alumina ceramics, quartz glass or boracic silica glass.
摘要:
A fire detector having a body comprising a cover part and a hood part and containing therein fire detecting means and electrical circuits, and a base detachably fastening the body by engaging means provided on them, respectively, is disclosed wherein in order to prevent the cover part from coming off the hood part due to shock, vibration, etc. possibly subjected thereto at the time of maintenance, inspection, etc. of the detector the cover part is provided on its upper surface with a plurality of vertically projecting posts each having at its upper end a hook member, the hood part being provided on its top wall with a corresponding number of openings each having an engaging portion formed at a part of the upper edge portion of the radially inner peripheral wall to be engaged by the hook members, respectively, and a corresponding number of grooves are provided in the upper surface of the top wall each in communication with a gap formed between radially outer walls of the grooves and the radially outer surface of the projecting post when the hook member engages the engaging portion, and a corresponding number of shifting members are provided on the under surface of the base which are adapted to be shiftably received in the grooves, respectively, to reach the respective gaps formed between the outer peripheral walls of the grooves and the radially outer surfaces of the posts when the engaging means provided in the body engage the engaging means provided in the base.
摘要:
Fire detection apparatus includes a fire detector panel and an accumulation-type control panel in which the fire detection element is non-latching but the fire voltage detection circuit includes a fire indicator which is latched when a fire signal is detected for longer than a predetermined time. The circuit for latching is controlled by an accumulation circuit in the control panel that controls a relay closing that generates a fixed voltage suitable for the fire indicator.
摘要:
A photoelectric smoke detector is provided with first and second radiation emitters and first and second radiation receivers. The first emitter emits pulsed radiation at a predetermined frequency. The second emitter emits pulsed radiation at twice this frequency. The first receiver receives the radiation of the second emitter directly and that of the first emitter by scattering only. When the first receiver receives alternate detection pulses reinforced by scattered radiation, an alarm is generated. The second receiver receives radiation directly from the first emitter and modulates the radiation output level of the second emitter proportionately. When the first receiver receives testing pulses between the alternating detection pulses, their level is discriminated to determine the functional state of the detecting elements and a corresponding function signal is generated.
摘要:
A sensor for detecting low concentrations of silane gas in air and a process for making the sensor are disclosed. The sensor comprises a silane-sensitive element and a heater to heat the element to 200.degree.-400.degree. C. The element comprises an electrode-equipped alumina porcelain tube coated with a mixture of SnO.sub.2, SbOCl, and Pt. The tube is calcined in air or in an oxidized antimony atmosphere at 600.degree.-850.degree. C. and is exposed to a silane atmosphere at 150.degree.-850.degree. C. to stabilize its properties.