Abstract: The present invention is directed to a system and method for accessing home monitoring devices remotely via a distributed wide-area network (WAN). More specifically, the present invention is directed towards smoke detector system, which monitors for the presence of smoke and communicates the smoke condition to a remote location. The smoke detection system comprises a smoke detection device connected to a communication device. The smoke detection device outputs a signal or a change in a signal upon detection of smoke. This signal or change in signal is monitored by the communication device. The smoke condition is then communicated to the remote central location via a message system.

Abstract: A gas detection instrument comprises a combustible gas sensor and associated circuitry, which supplies power to the sensor and measures and displays resulting sensor response. The supplied power is switched between timed pulses of electricity and steady state electricity, with the intermittent electricity being employed only when no significant change in sensor output has been detected. Alternatively, timed pulses of electricity are maintained, and predictive software algorithms are used to give readings for gas concentration during interruption of the power supply. The sensor operation enables the instrument to respond to rapid changes in gas concentration while minimizing power consumption of the sensor.

Abstract: A dispersion light smoke detector has a structure for providing a definite measuring volume, the structure being formed as two light receivers or an imaging optical system for one light receiver.

Abstract: A method and a fire-alarm system controls stationary fire-extinguishing systems. The fire-alarm devices of the fire-alarm system are equipped with one or more detectors. If at least one pre-adjustable alarm threshold of a fire identification characteristic is reached, the fire-extinguishing device is activated and the fire detectors are selectively switched to a higher stage of sensitivity. The detectors to be switched are locally selected depending on the actual development of the fire in terms of space. The dynamic adaptation of the sensitivity of the detectors to the development of a fire permits analyzing the development of the fire through the generated smoke, water vapor or extinguishing-water mist, and to influence the fire-extinction process in a targeted manner.

Abstract: A clock and ambient air condition sensing apparatus includes an alarm and ambient air sensor positioned in a housing and operatively connected to a logic circuit. The logic circuit is capable of evaluating air sensor data and energizing the alarm upon a preselected ambient air condition. A first battery is connected to the circuit for powering the air sensor. The housing includes a front cover pivotally movable between open and closed configurations. A clock is mounted to the front cover for displaying a relative time and is releasably electrically connected to the circuit. A second battery is connected to the circuit for powering the clock. The circuit is capable of evaluating the strength of the first and second batteries and of directing current from the second battery to the air sensor if the first battery is inoperable.

Abstract: A microcontroller-based hazardous condition detector having an intelligent hush feature is presented. The microcontroller controls the operational mode of the detector by monitoring a single user-actuated switch, the inputs from a smoke chamber and a carbon monoxide detector circuit, and the current operating mode of the detector. When in a normal or no-alarm mode, actuation of the switch will cause the microcontroller to place the detector in a test mode of operation. If the detector is in a carbon monoxide alarm mode, actuation of the switch will act to reset the accumulator function of the microprocessor for the carbon monoxide alarm sensing. If the detector is in a smoke alarm mode, actuation of the switch may place the detector in a hush mode if the level of smoke is sufficiently low, or will have no effect if the level of smoke is too high. Once in the hush mode, actuation of the switch will place the detector into the smoke alarm mode.

Abstract: An improved fire detector unit has a plastic base defining a smoke chamber for detection of a smoke density in terms of light scattering due to the smoke particles in the smoke chamber. The base carries a circuit board mounting a light emitting element, a light receiving element, and other components forming a fire detecting circuit responsible for generating a fire warning signal based upon the detected smoke density. A metal-made electromagnetic shield is molded into the base to protect the light receiving element from electromagnetic radiation noises. The electromagnetic shield includes a ground terminal for connection with a ground line of the circuit board. In addition, terminal pins are molded into the base for electrical and physical connection of the circuit board to the base.

Abstract: Provided is an alarm for detecting radiation, smoke and/or other air pollutants and includes detection means, first means for connection to a light fitting, and second means for connection to a light source. Electrical connection means connects the first means and the second means to enable the light source to be powered from the light fitting. In addition, a battery powers the alarm during periods of non-use of the light source, and isolating means thermally isolates the detection means from at least one of the electrical connection means, the light fitting and the light source.

Abstract: A mounting kit and smoke detecting apparatus releasably mountable to a distant support surface, including a smoke detector weighing W, a support plate securable to the support surface and releasably securable to the smoke detector by a separating force of Y, and a longitudinal member having a proximate end graspable by a user and a distal end releasably securable to the smoke detector. A selectable first connector on the distal end is releasably securable to the smoke detector for mounting the smoke detector to the support plate and a selectable second connector is securable to the smoke detector for detaching the smoke detector from the support plate. The first connector is secured to the smoke detector by a separating force no greater than X and the second connector is secured to the smoke detector by a separating force no less than Z. At least one of X<(Y−W) and X<Y is true, and at least one of Y<Z and (Y−W)<Z is true.

Abstract: A hush mode disabling device for a smoke alarm having a self-test function, a hush mode that engages upon activation of the self-test function to silence or desensitize the smoke alarm for a predetermined period of time, and a remote self-test controller. An improvement includes a hush mode disabler for determining whether the self-test function has presently been activated by the remote self-test controller and for disabling the hush mode if the self-test function has presently been activated by the remote self-test controller.

Abstract: A flame-sensing element and supporting circuitry is disguised by installing it in an object normally found within the type of room in which it is to monitor. In the best example, a lavatory is monitored by installing a mock fire-safety sprinkler head on the ceiling; the glass-bulb trigger element of a sprinkler head is replaced with a glass bulb flame-sensing element. Alternatively, the glass bulb flame-sensing element and associated electronics may be concealed in a housing designed to house a room deodorant, an air purifier of the ultraviolet or ozone-generating type, a reservoir for a liquid toilet bowl or urinal deodorant, behind the grille of a ventilating air vent, behind the grille of a loudspeaker housing, or within the housing of a smoke detector. The disguise or concealment is meant to hide the apparatus from notice by a surreptitious smoker who would smoke tobacco in an area wherein smoking is prohibited, especially in school lavatories.

Abstract: A smoke detector is provided with a light emission section holder having a light-emission element and a light receiving section holder having a light-receiving element. The light emission section holder and the light-receiving element are provided in a smoke detection section constituting a smoke detection space. The light emitted from the light-emission element is scattered by smoke entered the smoke detection space. The thus-scattered light is received by the light-receiving element,thereby detecting occurrence of fire. An insect screen is formed from soft fiber having a mesh pattern and is arranged so as to cover the entirety of the smoke detection section.

Abstract: Christmas ornament (10) for attaching to a Christmas tree, with a housing (12), which is preferably spherically shaped, the housing (12) being provided with a decorative outside, and at least one gas sensor (22), which, in case of detection of smoke, scorching or combustion gases triggers an acoustical and/or optical alarm (30, 26), the gas sensor (22) being arranged in the inside of the housing (12), the housing (12) being provided with gas inlet openings (24). Alternatively or additionally to the gas sensor (22) a position or inclination sensor (20) is arranged in the inside of the housing, which triggers an acoustical and/or optical alarm (30, 26) in case of a change of position or inclination of the Christmas ornament (10).

Abstract: In a flame ionization sensor type gas combustion control apparatus, the sensor is provided with a power supply which will increase the voltage as contamination build up occurs on the in-flame sensor electrode thereby keeping a constant sensor current and enabling the sensor to perform as intended even though insulative contaminant build up is present on the electrode.

Abstract: A smoke alarm device has an ASIC (1) with an integrated photo detector (3) and control circuit. The photo detector output is compared every ten seconds with an alarm threshold level in a comparator circuit (10), with a sensitivity-decrease threshold in a comparator circuit (11), and with a sensitivity-increase threshold in a comparator circuit (12). A logic block (2) causes sensitivity to be increased or decreased in which decreases take place at intervals of six hours and increases take place after 40 secs. The logic block (2) provides for least sensitivity at power-up with rapid increases to the appropriate level according to the level of back-scatter caused by dust contamination. The logic block (2) maintains a high signal on an interconnect terminal (9) for four seconds after a test button (7) is pressed so that a maintenance person can hear remote interconnected devices after the local device has stopped sounding.

Abstract: A smoke sensor and a carbon monoxide sensor are integrated into a common detector housing. The smoke sensor is coupled to a smoke detector control integrated circuit which generates a binary output signal indicative of the presence of smoke. This signal is coupled to a programmed microprocessor in the detector housing. The carbon monoxide sensor is also coupled to the microprocessor. Outputs from the two sensors are processed substantially independently. In the presence of smoke, the smoke alarm is generated by the microprocessor. In the presence of sufficient levels of carbon monoxide, in the absence of smoke, a carbon monoxide alarm will be generated.

Abstract: A method and apparatus is provided for detecting airborne particles in an electronic enclosure. The electronic enclosure may be used to house one or more electronic devices or components of an electronic system, such as a computer or data storage system. A particle detection system is provided to monitor the air within the enclosure and to generate an alarm signal in response to detection of a threshold level of airborne particles within the enclosure that is indicative of an operational anomaly associated with at least one of the electronic devices or components. In response to the alarm signal, the electronic devices housed within the enclosure may be automatically shut down to reduce potential damage to at least the devices housed within the enclosure. The detection system is particularly suited for detecting the presence of smoke within an electronic enclosure, such as may be generated during a combustion event by overheated or electrically shorted electronic components.

Abstract: A smoke detector that is easily attached to the limb of a Christmas tree that includes a smoke detector circuit and an audible alarm circuit for generating an audible alarm in response to detecting smoke. The smoke detector circuit is capable of detecting small amounts of smoke and triggering an alarm. An additional fire detector element is also provided in the form of an infrared detector that detects rapid changes in infrared levels and generate an activation signal for causing the speaker to generate an audible alarm. The housing of the smoke detector has a Christmas decoration theme so as to not detract from the decorations on the Christmas tree.

Abstract: A smoke detector has a geometry that locates a sensor or sensors at or near a boundary layer of smoke movement thus facilitating smoke entry into the sensor and/or sensors. The sensors are mounted so as to protrude from the bottom of a cover instead of into the cover of the detector.

Abstract: A sounder assembly comprising a housing, means for providing a sounder plate; a base for attaching the sounder assembly to a support surface, and an electrical sounder mounted generally within the housing, the arrangement being such that, in use, the sounder plate is spaced from the housing and is located between the housing and the support surface, with the electrical sounder facing the sounder plate such that sound is generated towards the sounder plate and is directed away from the housing so that the sound emerges generally laterally of the sounder plate, and wherein the sounder plate is concave and the center of the electrical sounder is displaced from the center of the sounder housing.

Abstract: A smoke alarm having both an ionization detector and a photoelectric detector coupled to each other to generate an alarm signal when either of the detectors senses a potential fire. The smoke detector includes a power supply circuit having both an AC power supply and a DC battery power supply. During normal operating conditions, the AC power supply operates both the ionization detector and the photoelectric detector of the smoke alarm. Upon power interruption, the DC battery supply provides power to operate both the ionization detector and the photoelectric detector. The smoke alarm includes an interconnect that allows multiple smoke alarms to be coupled together.

Abstract: A low power local alarm indicating system for interconnectable detectors enables a viewer to, after the fact, determine which detector or detectors had previously gone into a local alarm. An alarm latch, such as a bistable multi-vibrator circuit, is set each time the respective detector goes into a local alarm. Subsequently, if the detector's test switch is activated, a local alarm visual indicator is provided. In a disclosed embodiment, the indication is provided by blinking a light emitting diode on the detector, for a predetermined interval. Where multiple detectors are interconnected, each detector that goes into alarm not only sets its local alarm latch and emits a local alarm, it also generates an interconnect alarm signal to the remaining interconnected detectors. The interconnected detectors go into alarm at least for as long as the interconnect signal is present.

Abstract: The present invention provides an adverse condition detection apparatus that enables a user to test the apparatus in close proximity without having to endure fully operational alarm noise. In one embodiment, the apparatus includes a detector, a transducer, and a test system. The detector provides an adverse condition signal in response to detecting an adverse condition (e.g., smoke). The transducer is operably connected to the detector for receiving the adverse condition signal. The transducer generates an operational alarm in response to receiving the adverse condition signal when the detector detects the adverse condition. The test system is operably connected to the transducer and causes it to generate a test alarm in response to a user activating the test system. However, the test alarm, at least initially, is lower in audibility than the operational alarm.

Abstract: A wireless detection system for monitoring a predetermined area for an emergency situation. The wireless smoke detection system includes a plurality of detector units strategically positioned throughout the monitored area. Each of the plurality of detector units include a detector for sensing one of a characteristic and condition within a section of the monitored area and generating a signal indicative of the monitored. A signal processor is connected within each detector unit for analyzing the signal generated by the detector and upon determining if the signal is above a predetermined level generating an emergency signal. A transmitter is provided for transmitting the emergency signal to a plurality of receiver units strategically positioned about the monitoring area. Each receiver unit includes an alarm for generating an alarm signal and thereby alert persons to the emergency situation at a position within the monitored area.

Abstract: The present invention is directed to a system and method for accessing home monitoring devices remotely via a distributed wide-area network (WAN). More specifically, the present invention is directed towards smoke detector system, which monitors for the presence of smoke and communicates the smoke condition to a remote location. The smoke detection system comprises a smoke detection device connected to a communication device. The smoke detection device outputs a signal or a change in a signal upon detection of smoke. This signal or change in signal is monitored by the communication device. The smoke condition is then communicated to the remote central location via a message system.

Abstract: An ionization chamber that detects changes in temperature of electrical insulation with a corresponding change in voltage. This voltage change can be relayed through an operational amplifier and a comparator to a device receiving the signal, thus triggering the necessary alarm and preventing fires caused by electrical arcing.

Abstract: A smoke detection system comprises a manifold (4) connected to a series of sampling pipes (2). A fan (6) which draws a large volume of sampling air through the sampling pipes is connected to the inlet manifold and a small proportion of that air is directed to the inlet of a smoke detector (12), the outlet of which is connected to the manifold. The configuration obtained by the connection of the outlet from the detector into the inlet manifold provides a large pressure drop across the flow path through the detector. As a result of the large pressure drop, a filter (10) for removing dust and other contaminants can be incorporated in the flow path and the filter can also incorporate a fine filtering stage to produce a secondary clear air flow which can be directed into the detector to prevent smoke particles from settling on critical components of the detector.

Abstract: A detector includes a sensor of an ambient condition. Outputs from the sensor are sampled at a predetermined rate when the outputs do not represent an alarm condition. The outputs are analyzed using pattern recognition techniques to determine if a predetermined profile, which precedes the presence of an alarm condition, is present. In the event that the profile is detected, the sample rate is increased along with associated sample value processing. The detector includes a programmable processor coupled to the sensor. The processor includes pattern recognition instructions for detecting the presence of the predetermined profile. The processor also includes instructions for altering the sampling rate in response to the detected presence of the profile. A second sensor can be incorporated to provide sample rate altering signals.

Abstract: The fire detector for sensing a fire, comprises; a smoke chamber, a light emitting element, and a light detecting element for detecting a scattered light caused by scattering a light emitted by the light emitting element with a smoke which enters in the smoke chamber, wherein a wall part of the smoke chamber is formed in a shape based on a circle having a predetermined size, and comprises a projecting portion which projects from at least a part of the circle to an outside of the circle, the light emitting element is disposed on the projecting portion of the smoke chamber, and the light detecting element is arranged out of the smoke chamber and an optical axis thereof is approximately perpendicular to a plane including the circle.

Abstract: An improved fire detector is obtained by combining a conventional smoke particle sensor with a fire radicals odor sensor; the latter being an electronic nose tuned to respond to the presence of a family of radicals, produced by most fires, that is responsible for the odor associated with a fire. The conventional smoke particle sensor is prevented from producing an alarm signal unless the tuned electronic nose senses that the fire-produced radicals are increasing at a rate that exceeds a preset threshold rate. In another aspect of the invention, the smoke particle sensor is provided with a second, lower, threshold connected to a timer so that an alarm will be produced if the lower threshold is exceeded, without interruption, for a preset time. The improved fire detector, using the combined sensors, has greater sensitivity and a lower false alarm rate.

Abstract: A warning apparatus provides an alarm indication of the location of an exit from an enclosure or room in the event of a detected fire as well as the safety of the exit. An alarm housing is located remote from a smoke detector on or in proximity to a surface of the exit. The smoke detector output is an ultrasonic frequency signal generated upon detection of a fire. The ultrasonic signal is detected by a receiver carried by the alarm which activates the alarm. The alarm is in the form of at least one, and preferably both of a visible light and an audible alarm mounted within the alarm housing. A temperature sensor on the alarm housing detects the temperature of the exit surface and deactivates the alarm if the temperature exceeds the predetermined safe temperature. A test circuit is included in the smoke detector or on a separate transmitter which, when activated, transmits an ultrasonic signal to the receiver to test the proper operation of the alarm.

Abstract: A fire and smoke detector utilizes a statistical analysis of the near infrared radiation incident on it. The spectral radiation intensities incident on the fire detector are continuously measured at two near-infrared wavelengths, and a time series of apparent source temperatures is obtained from these measurements. The power spectral density and the probability density function of the apparent source temperatures are sufficient to determine the presence of a fire in the vicinity of the detector. The detector can indicate the presence of a fire in an adjoining room from the radiation which is incident on it due to reflections from common building materials. The present invention relates to fire and/or smoke detection methodology and associated apparatus. The detector utilizes fiber optic as a viewing and absorption/scattering detection means.

Abstract: A pump failure alarm system which is provided in a hydraulic working machine comprising hydraulic pumps driven by a prime mover, delivery lines joining with one another into one common delivery line on the downstream side, check valves provided in the delivery lines upstream of a point where the delivery lines join with one another, a hydraulic cylinder driven by a hydraulic fluid introduced through the common delivery line, and a hydraulic reservoir. The pump failure alarm system comprises pressure sensors for detecting respective delivery pressures of the hydraulic pumps, bypass lines having one ends connected to the delivery lines at points upstream of the check valves and the other ends connected to the hydraulic reservoir, solenoid switching valves for opening and closing the associated bypass lines, an alarm display unit for giving an alarm in correspondence to each of the hydraulic pumps, and a controller.

Abstract: Smoke alarms that incorporate dust repelling screens exhibit improved performance with fewer false alarms. Effective screens include conductive strands combined with non-conductive elements.

Abstract: An ionization smoke detector comprising: an inner electrode; an intermediate electrode having an electrode body and an electrode piece extending from the electrode body, facing the inner electrode and connected to a field effect transistor; an outer electrode provided in an opposite side to the inner electrode with respect to the intermediate electrode; and an insulating supporter for supporting the intermediate electrodes to face the inner electrode.

Abstract: An ultraloud ambient condition detector incorporates a sensor in combination with a control circuit. An alarm indicating signal from the control circuit energizes a multi-frequency drive circuit which produces a band of output frequencies usable to drive a piezoelectric output element. The output element has one or more resonant frequencies which fall within the band of the drive frequencies. A feedback circuit is provided to maintain the unit in an alarm state, after it has switched into that state, even if the input ambient condition indicator signals a decline in the value of the sensed ambient condition or in the presence of noise perhaps generated by the audio output device. A high current, low duty cycle battery test current repetitively loads the battery consistent with current load when the detector is in an alarm state.

Abstract: Gas pressure in a chamber is determined by injecting alpha particles. The alpha particles ionize the gas. By determining a number of gas ions which are ionized, the pressure of the gas in the chamber can be determined.

Abstract: An extra security alarm system for monitoring conditions within a predetermined monitoring area and alerting persons located throughout the monitoring area, persons in the vicinity and appropriate emergency personnel of an emergency situation. The extra security alarm system includes a plurality of sensors strategically positioned throughout the monitoring area for sensing conditions within the monitoring area. Each of the sensors includes a control unit for analyzing the sensed conditions to determine if an alarm situation exists and generating a sensor signal indicative of the sensed conditions, a transmitter for transmitting the generated signal to the other sensors, a receiver for receiving sensor signals from the other sensors and an alarm for generating an alarm signal upon determining an alarm condition has been sensed by the system.

Abstract: A bar code reader includes a laser source for emitting a laser beam, and a scan device for scanning a bar code with the laser beam according to a predetermined scanning pattern. A window passes the laser beam from the scanning device toward the bar code which is in the vicinity of the window. A condenser condenses reflected light return from the bar code through the window and scanning device along the route traced by the laser beam. A photosensor detects the condense light and provides an electric signal which is proportional to the intensity of the detected light. A main body accommodates the laser source, the scanning device, the window, the condenser, and the photosensor. A cover is attached to the main body, and has an opening corresponding to the window. A buzzer is provided, to create a buzzing sound which resonates in a space formed between the main body and the cover.

Abstract: A Christmas tree ornament-shaped fire alarm is provided including a housing shaped as a Christmas ornament and having an interior space. The housing is adapted to be situated on a Christmas tree. Further provided is a fire alarm situated within the housing for providing an indication to a user upon the detection of the Christmas tree being on fire.

Abstract: A very low profile ionization chamber provides increased operating current by using alpha particle emitting isotopes having low emission energies as an ionization source. The chamber includes a cylindrically shaped housing having height generally equal to a radius thereof. A conically shaped sensing electrode is carried within the housing. The housing is closed at one end by a main field electrode and at the other end by an insulating closure panel. A second field electrode is carried on the closure panel. The second field electrode also carries the ionization source. The conically shaped sensing electrode has an open central region which permits alpha particles to travel therethrough toward the first field electrode. The first field electrode could either exhibit a conical cross-section or could be planar. A chamber height on the order of 1.5 to 2 centimeters and a diameter in a range of 3-4 centimeters with a Gd148 source produces operating currents on the order of 10 pA.

Abstract: A smoke/heat detector in the form of a Christmas tree ornament utilizes a spherical ornament housing divided by a fire-resistant barrier into lower and upper chambers. A transmitter circuit is mounted atop the barrier and transmits signals to a remote receiver upon detection of entry of smoke or heat into the lower chamber by means of sensors therein. Upon receipt of the transmitted signals by a remote receiver, an energized alarm circuit sounds an alarm indicative of the smoke or fire presence. Both circuits include SCR components and internal power sources so that the circuits, once initially energized, will continue to transmit signals and/or sound the alarm after initial start up.

Abstract: The invention provides a self-contained automatic fire detection, warning, and suppression life safety system having an extinguishant source and a fire detector coupled to an electronic processor. The processor has logic to interface with components for detecting and warning of a fire and releasing the extinguishant. Self-diagnosis logic checks the entire system's function, pressure, power level, and power source. Additional sensors are provided for detecting various hazards, and the processor has logic for proper response.

Abstract: A combination smoke, carbon monoxide and hydrocarbon detector including a smoke detection mechanism adapted to transmit a smoke signal upon the detection of smoke, a carbon monoxide detection mechanism adapted to transmit a carbon monoxide signal upon the detection of carbon monoxide, and a hydrocarbon detection mechanism adapted to transmit a hydrocarbon signal upon the detection of hydrocarbon. Next provided is an audio alarm mechanism situated within the housing and connected to the each detection mechanism. The audio alarm mechanism is adapted to emit a high intensity audio alarm upon the receipt of a signal, whereby the type of audio alarm is unique to the signal received. Further provided is control circuitry having a first mode of operation when only one signal is received from the detection mechanism whereby the control circuitry continuously transmits the one signal to the audio alarm means upon the receipt thereof.

Abstract: A smoke detector (10) has internal self-adjustment and self-diagnostic capabilities. It includes a microprocessor-based alarm control circuit (24) that periodically checks the sensitivity of a smoke sensing element (20) to a smoke level in a spatial region (12). The alarm control circuit and the smoke sensor are mounted in a discrete housing (25) that operatively couples the smoke sensor to the region. The microprocessor (30) implements a routine (50) stored in memory (32) by periodically determining a floating adjustment (FLT.sub.-- ADJ) that is used to adjust the output (RAW.sub.-- DATA) of the smoke sensing element and of any sensor electronics (40) to produce an adjusted output (ADJ.sub.-- DATA) for comparison with an alarm threshold. The floating adjustment is not greater than a maximum value (ADJISENS) or less than a minimum value (ADJSENS). Except at power-up or reset, each floating adjustment is within a predetermined slew limit of the immediately preceding floating adjustment.

Abstract: A multiple sensor smoke detector includes at least an ionization and a photoelectric sensor. Outputs from the sensors are fed to circuitry for generating continuously variable coefficients. One coefficient corresponds to each sensor output. Respective coefficients and sensor outputs are multiplied in multiplier circuitry to produce processed outputs. The processed outputs are combined in a summing circuit to produce at least one output value indicative of a level of detected smoke. The coefficient generating circuitry, the multiplier circuitry and the combining circuitry could be implemented in a programmed microprocessor. The coefficient generating circuitry could be implemented using prestored membership functions indicative of various types of fires.

Abstract: A multi-signature fire detection method and apparatus, utilizing first and second detectors for detecting first and second fire signatures. The first detector outputs a first signal indicative of the first detected fire signature, and the second detector outputs a second signal indicative of the second detected fire signature. A signal processor is provided for combining the first and second signals using a number of correlations, wherein outputs of the first and second detector means are coupled to the signal processor, and the signal processor compares and combines the first and second signals to a first predetermined reference value, and outputs a fire condition signal if a combination of the first and second signals exceeds the predetermined reference value.

Abstract: A light scattering type smoke detector arranged such that even if the range in which light from an LED is emitted has a dispersion, a labyrinth member 90 in the light emitting range has no edge or only a predetermined labyrinth member exist therein. The labyrinth member 90 is preferably formed by a single plate larger than the other labyrinth members 9. The edges of the labyrinth members 9 are preferably formed to a curved surface or chamfered, and the dispersion of the 0 point of a detection output is reduced and the level of the 0 point of the detection signal is lowered to thereby accurately detect light scattered by smoke.

Abstract: An ionization chamber for use in a smoke detector includes first and second outer electrodes and a non-reflective center electrode. The non-reflective center electrode can be formed as a metal electrode having a non-reflective coating or as a non-reflective, conductive plastic elements. The ionization chamber can be incorporated into combination smoke detector which includes a photoelectric sensor. A non-reflective center electrode, associated with the ion-type sensor is symmetrically located in the detector and displaced from the photoelectric sensor.

Abstract: A photoelectric type fire detector is capable of accurately adjusting sensitivity using a scattering and translucent plate and exhibits excellent reliability.