Abstract: Provided is a sensor 100 provided with a detection element 700 for detecting heat of a heat air current generated in association with a fire in a monitoring area, in which the detection element 700 is disposed so that a detector protrudes from a predetermined base portion of the sensor 100, the sensor 100 includes a control structure that has a stepped portion higher than the predetermined base portion, the control structure being configured to guide the heat air current to the detector of the detection element 700 along an outer peripheral wall of the stepped portion, at least a part of the detector of the detection element 700 is located on a base portion side lower than the uppermost step of the stepped portion, a labyrinth portion guides the heat air current to the detector of the detection element 700 along a side end portion corresponding to an outer peripheral side of the stepped portion of a plurality of partition walls, and the heat air current containing smoke introduced into the labyrinth portion i

Abstract: A device includes a housing, one or more sensors configured to detect at least one of a voltage or a current in proximity to the device, one or more lighting elements configured to output light responsive to the one or more sensors detecting the at least one of the voltage or the current in proximity to the device, one or more speakers configured to output audio responsive to the one or more sensors detecting the at least one of the voltage or the current in proximity to the device, one or more network interfaces configured to communicatively couple the device to one or more additional devices, and one or more fastening mechanisms configured to secure the device to a surface.

Abstract: Devices, methods, and systems for monitoring a self-testing fire sensing device are described herein. One device includes a memory, and a processor configured to execute instructions stored in the memory to receive, from a self-testing fire sensing device, measurements of outputs of light-emitting diodes (LEDs) of the self-testing fire sensing device during operation of the self-testing fire sensing device, determine when a deviation in the measured outputs of the LEDs of the self-testing fire sensing device meets or exceeds a threshold deviation amount, determine an action to take on the self-testing fire sensing device upon determining the deviation in in the measured outputs of the LEDs meets or exceeds the threshold deviation amount, and send a notification of the determined action to take on the self-testing fire sensing device to an additional computing device.

Abstract: A smoke detection device comprises a housing, a control unit with a power unit, and a scattered light sensor. The sensor comprises an optical chamber having a first emitter, a second emitter, and a photoreceiver therein. The optical chamber is within a filtration chamber having output openings that are coupled to the optical chamber via a labyrinth that terminates as a ring slit between the optical chamber and the filtration chamber. The control unit constantly provides power impulses to the first emitter, and connects the second emitter to the power unit at a moment when a threshold signal arises at the photoreceiver, determines signal levels of the photoreceiver that arise during providing of the power impulses to the first and the second emitters, and initiates an alarm if the level within the second emitter connection period is at least 20% greater than the level within the first emitter connection period.

Abstract: Multi-mode operation of fire alarm devices is described herein. One device includes a self-test component, an alarm component, and a power supply configured to operate in a first mode to provide power to the self-test component and operate in a second mode to provide power to the alarm component.

Abstract: Example implementations include a smoke detector comprising a smoke chamber; an LED that generates light in the smoke chamber; a photodetector configured to detect whether a threshold amount of light is scattered by smoke particles in the smoke chamber; and one or more self-testing components configured to re-direct the light from the LED toward the photodetector for self-testing the LED and the photodetector. Some further implementations include one or more masking self-test components configured external to the smoke chamber to direct light from outside the smoke chamber into the smoke chamber and toward the photodetector for determining whether the smoke detector has been masked. Some further example implementations include a method comprising controlling one or more self-testing components of a smoke detector to re-direct at least a portion of light from an LED toward a photodetector; and determining whether the photodetector causes an alarm trigger in response to the controlling.

Abstract: An optical particulate detection system for an aircraft is provided. The optical particulate detection system includes an optical particulate detector and a controller. The optical particulate detector includes at least two optical sources and at least one optical sensor distributed in series with respect to a flow path of a component surface of the aircraft. The controller is configured to interface with the optical particulate detector, monitor the at least one optical sensor, and characterize one or more particles of foreign object debris based on a pulse width and two or more scattering ratios determined with respect to light emitted from the at least two optical sources.

Abstract: Devices, systems, and methods for providing smoke detectors are described herein. One smoke detector of a fire sensing system includes a circuit board body, having a set of front scattering emitting light sources located on one side of an optical chamber, a receiver of front scattering light beams from the front scattering emitting light sources and backward scattering light beams, and a set of backward scattering emitting light sources located between the set of front scattering emitting light sources and the receiver, the backward scattering light beams emitted from the backward scattering emitters.

Abstract: An operation control method suitable for a fire extinguishing system of an extra-high voltage converter station is provided. The method includes: after an upper computer control system receives a sound-light alarm signal, an alarm position signal, and a switch position dividing signal, starting a spray range prediction analysis subsystem for a fixed fire monitor; determining, by the spray range prediction analysis subsystem for the fixed fire monitor based on an external wind direction and an external wind speed, whether a range of a fire monitor effectively covers an entire area of a converter transformer; and if yes, automatically presetting a first fire monitor to which a first compressed air foam generation subsystem belongs and a second fire monitor to which a second compressed air foam generation subsystem belongs; or if no, replacing a fire monitor with a mobile fire-fighting robot to extinguish a fire.

Abstract: There is provided an optical machine of a smoke detector including a substrate, a light source, a light sensor and a light blocking member. The light source and the light sensor are arranged on the substrate in a first direction. The light blocking member is arranged upon the light source and blocks a part of an emission angle of the light source in the first direction far away from the light sensor.

Abstract: A method of hushing one or more fire detectors of a fire detector system including: receiving an alert using a computer application of a trusted individual computing device, the alert indicating that fire has been detected by at least one of the one or more fire detectors; searching for a wireless advertisement emitted from the one or more fire detectors in response to the alert using the computer application; detecting the wireless advertisement being emitted from the one or more fire detectors using the computer application; and receiving a manual input via an input device of the trusted individual computing device to hush the fire detector from a trusted individual in possession of the trusted individual computing device; and transmitting a hush request to the one of the one or more fire detectors in response to the manual input using the computer application.

Abstract: A smoke detector includes a substrate, an optical detection module, a base and a top cover. The substrate has a ring shape region surrounding a central detection region, and a first block structure of the central detection region is protruded from the substrate and higher than an upper surface of the ring shape region. The optical detection module is disposed inside the central detection region. The base is disposed on the substrate and around the optical detection module. The base has a second block structure. The top cover is connected to the base. A lateral wall of the top cover is partly overlapped with the second block structure to form a guiding channel. The optical detection module analyzes variation of scattering parameters resulted from gaseous matter entering the top cover through the guiding channel for determining concentration of the gaseous matter.

Abstract: Provided is an apparatus for detecting smoke based on polarization. The apparatus includes a chamber into which smoke is introduced, a detection unit comprising a light-emitting unit configured to emit light beams having a plurality of different wavelengths into a space in the chamber, and a light-receiving unit configured to receive scattered light from a plurality of light sources, a control unit configured to control an operation of the detection unit, and a fire determination unit configured to distinguish between fire smoke and non-fire analogous smoke by detecting and analyzing a light-receiving signal received by the light-receiving unit, in which horizontal polarization and vertical polarization are applied to the plurality of light sources of the light-emitting unit and the light-receiving unit.

Abstract: A smoke detection apparatus based on multiple wavelengths is provided, which includes: a chamber configured to receive an inflow of a smoke; a detector including a light emitter having a plurality of light sources that radiate light having a plurality of different wavelengths into a space in the chamber, and a light receiver configured to receive scattered light by the plurality of light sources; and a controller configured to control an operation of the detector and to distinguish between fire smoke and non-fire quasi-smoke by detecting and analyzing a light receiving signal of the light receiver.

Abstract: A detection chamber assembly of a smoke detector is provided. The detection chamber assembly includes upper and lower covers, louvers and a corrugated bug screen. The louvers are arranged with the upper and lower covers to define a chamber bound between the upper and lower covers and the louvers. The louvers include a first pair of louvers defining a first space therebetween to permit fluidic ingress to the chamber and a second pair of louvers defining a second space therebetween to permit fluidic ingress to the chamber. The second space is wider than the first space. The corrugated bug screen includes a body disposed about the louvers and a mesh corrugation feature coupled to the body at the second space to permit fluidic ingress to the chamber at the second space and to inhibit bug ingress to the chamber at the second space.

Abstract: The invention relates to a housing for a detection unit for optically detecting smoke particles. The detection unit has a light source for emitting radiation to be scattered by smoke particles to be detected and a light detector for detecting the scattered radiation. The housing 2 has a cylindrical outer surface 7 having smoke openings 8 through which the smoke particles enter housing 2, and a radially symmetric light-guiding structure 9 with guide members. The guide members are so designed that adjacent guide members each form a guide channel through which the radiation emitted from the light source and not scattered by the smoke particles is guidable to the outside in the direction of the smoke openings 8 by multiple reflection. Higher detection sensitivity for optically detecting smoke particles can be achieved as a result.

Abstract: A smoke detection device includes a housing, a smoke collector, an optical detector and a cover plate. The housing has a piercing hole. The smoker collector has a smoke hole, and position of the smoke hole is close to position of the piercing hole. The optical detector is disposed inside the smoke collector and adapted to detect gaseous concentration inside the smoke collector. The cover plate is disposed between the housing and the smoke collector, and used to set a channel from the piercing hole to the smoke hole, so that gaseous matter flows from outside the smoke detection device into the smoke collector through the piercing hole and the smoke hole.

Abstract: Non-coaxial systems, methods, and devices for detecting smoke are described herein. A smoke detection system may comprise a laser emitter configured to emit a laser beam, and a light receiver. The light receiver may comprise a first receiver lens, wherein a field of view of the first receiver lens includes at least a portion of the laser beam. The light receiver may also comprise a second receiver lens, wherein a field of view of the second receiver lens includes at least a portion of the laser beam and a region between an edge of the field of view of the first receiver lens and the laser emitter.

Abstract: Analog signal measurement and related apparatus, systems, and methods are disclosed. Such an apparatus may include a signal analyzing circuitry to enable responsive to the assertion of the first enable signal, compare the amplified analog input signal to one or more threshold values responsive to the assertion of the second enable signal, and generate an alert signal responsive to a determination that the amplified analog input signal falls outside of the one or more threshold values.

Abstract: A fire detection apparatus 1A includes a heat detection unit 110A provided such that a part of the heat detection unit 110A is accommodated in an outer cover 20A and another part of the heat detection unit 110A is exposed to an outside of the fire detection apparatus 1A through an insertion hole 120A formed in a top surface portion 22A, and a guard portion 130A which is provided to cover a periphery of the insertion hole 120A and another part of the heat detection unit 110A in the top surface portion 22A and has a plurality of ribs, in which a material of a rib corresponding to a first guard side rib 131A among the plurality of ribs is made different from a material of some other ribs, or a shape of the first guard side rib 131A among the plurality of ribs is made different from a shape of some other ribs.

Abstract: A particulate matter sensor device comprising an enclosure (21) that comprises a flow inlet (11), a flow outlet (12) and a flow channel (2) extending therebetween, a radiation source for emitting radiation into the flow channel (2) for interaction of the radiation with the particulate matter in the flow (20) of an aerosol sample when guided through the flow channel (2), a radiation detector (4) for detecting at least part of said radiation after interaction with the particulate matter. The sensor device comprises a flow modifying device (511) arranged upstream of the radiation detector (4) and/or of the radiation source (3) for modifying the flow (20) for reducing particulate matter precipitation onto the radiation detector (4) and/or onto the radiation source (3) and/or the channel wall sections in close proximity to the detector (4) and/or source (3). The invention also relates to a method of determining parameters of particulate matter in an aerosol sample by using such a particulate matter sensor device.

Abstract: A fire detection system for monitoring a monitored environment includes a smoke detector configured to determine a concentration of smoke in a sample of air from the monitored environment; a gas sensor configured to determine a concentration of a predetermined gas in the sample of air, the predetermined gas is one of carbon monoxide, carbon dioxide, nitrogen dioxide and sulphur dioxide; and a control module in communication with the smoke detector and the gas sensor; the control module is configured to identify a source of the smoke based on the concentration of smoke and the concentration of the predetermined gas; and the source of the smoke is identified to be a non-fire source when the concentration of the predetermined gas in the sample of air is below a first threshold.

Abstract: An optical smoke detector 1 includes an ultrasonic transducer 4 configured to cause oscillations in its housing 2 so as to dislodge accumulated particulate matter from the walls of a sensor chamber or a labyrinth of the smoke detector 1. Additionally or alternatively, the ultrasonic transducer 4 may be configured to cause oscillations that dislodge accumulated particulate matter from a light source or a light receiver of the smoke detector 1.

Abstract: A light-receiving element and a first light-emitting element are disposed in a position in which the light-receiving element receives forward-scattered light produced when smoke in the smoke detection part is irradiated with first irradiation light emitted from the first light-emitting element. A secondary reflecting plate is provided on a side of the first light-emitting element inside the peripheral wall. The secondary reflecting plate is configured to form secondary reflected light when the smoke detection part without smoke is irradiated with the first irradiation light. The secondary reflecting plate receives primary reflected light resulting from reflection of the first irradiation light from the peripheral wall and reflects the primary reflected light, and then allows the formed secondary reflected light to enter the light-receiving element.

Abstract: Devices, methods, and systems for a self-testing fire sensing device are described herein. One device includes a fan, an optical scatter chamber configured to measure a quantity of particles therein, and a controller configured to compare the quantity to a baseline quantity and transmit a command to a fan responsive to the quantity being greater than the baseline quantity, wherein the fan is configured to activate for a particular period of time to remove particles from the optical scatter chamber responsive to receiving the command, wherein the optical scatter chamber is configured to measure the quantity of particles therein after the particular period of time, and wherein the controller is configured to compare the quantity of particles after the particular period of time to the baseline quantity and report a confirmed fire responsive to the quantity of particles after the particular period of time being greater than the baseline quantity.

Abstract: Light fixtures and safety detection systems are provided that enable smoke detection devices to be installed in a manner that is out-of-sight, thus alleviating the need to unsightly smoke detection devices to be installed throughout a building. The safety detection system comprises: an electrical fixture, for installation in a building; and a smoke detection device, for detecting at least smoke in the building. The smoke detection device is integrated with the electrical fixture such that the smoke detection device is concealed when installed.

Abstract: A life safety device includes a housing, a detector for detecting one or more conditions, and an actuatable mechanism coupled to the housing. The actuatable mechanism includes a light assembly operable in response to detection of at least one of the one or more conditions.

Abstract: A system includes a depression, a liquid, a gas inlet, an aspiration system, an aspirator, and a gas detector. The depression is formed into a floor. The liquid is disposed within the depression. An unoccupied space is delineated by a surface level of the liquid and a depth of the depression in the floor. The gas inlet is located within the unoccupied space in the depression. the aspiration system is connected to the gas inlet by a tube and located outside of the depression. The aspirator is located within the aspiration system and configured to create a vacuum to draw a gas mixture from the unoccupied space into the aspiration system using the gas inlet and the tube. The gas detector is located within the aspiration system and is configured to detect a specific gas.

Abstract: An optical chamber assembly of a life safety device includes a light ring for supporting at least one light device and an optical cover defining an interior chamber of the optical chamber assembly. The optical cover has a plurality of side members spaced from one another to define a plurality of smoke flow paths connected to the interior chamber. A light cover is disposed between the light ring and the optical cover and optically couples the at least one light device with the interior chamber. A primary smoke entry location is defined by at least one of the plurality of smoke flow paths in the optical cover and a secondary smoke entry location distinct from the primary smoke entry location is arranged in fluid communication with the interior chamber.

Abstract: A detector device includes a light source disposed within a chamber, a sensor disposed within the chamber, a compensator circuit electrically coupled with the sensor, and a controller. The controller is operable to receive a sensor signal generated by the sensor, determine a compensation factor to adjust the sensor signal, and generate a compensation offset signal based on the compensation factor. The controller is further operable to output the compensation offset signal to the compensator circuit to produce a compensated sensor signal as an adjustment to the sensor signal, energize the light source, monitor the compensated sensor signal with respect to an alarm limit, and trigger an alarm event based on the compensated sensor signal exceeding the alarm limit.

Abstract: The present disclosure concerns a smoke detector (1) including: a detection chamber, a baffle system surrounding the chamber enabling to isolate the chamber from outer light and enabling air to flow from the outside to the inside of the chamber, and a mechanical actuator capable of cleaning, in case of an obstruction, intervals between the elements.

Abstract: A particle detector formed by a body defining a chamber and housing a light source and a photodetector. A reflecting surface is formed by a first reflecting region and a second reflecting region that have a respective curved shape. The curved shapes are chosen from among portions of ellipsoidal, paraboloidal, and spherical surfaces. The first reflecting region faces the light source and the second reflecting region faces the photodetector. The first reflecting region has an own first focus, and the second reflecting region has an own first focus. The first focus of the first reflecting region is arranged in an active volume of the body, designed for detecting particles, and the photodetector is arranged on the first focus of the second reflecting region.

Abstract: A smoke or fire detector is described for mounting on a ceiling. A first part (110) is for mounting on the ceiling and a second part (110) houses a detector. The second part has a top-plate (116) with an annular recess. Electrical connections are arranged above the recess. A pair of drains (111) are provided through a surface of the recess, with conduits (113) extending downwards from the drains. The annular recess directs condensation to the drains (111) and down through the conduits (113), away from the electrical connections. In use, a differential air pressure between a ceiling void above and a lower surface of the smoke or fire detector provides a stack effect to assist drainage of condensation.

Abstract: A server associated with a building automation emergency response system, receives indications of a detected emergency from sensors distributed among zones in the building, comprising a sensor reading level and a sensor identity. The server determines a zone danger level, based on the sensor identity and on the sensor reading levels. The server calculates an evacuation route commencing from user interfaces distributed among the zones. The user interfaces include a display device. The evacuation route is calculated to traverse the zones with a lower route danger level. The evacuation route is directed toward a safe exit, based on a floor plan. The server then transmits a depiction of the evacuation route to the user interfaces for display. The server continues receiving updated indications from the sensors, determines updated route danger levels, calculates an updated evacuation route, and transmits an updated depiction of the evacuation route to the user interfaces for display.

Abstract: A fire detection apparatus 1 includes a first light emitting unit 101 that irradiates a detection space located inside or outside the fire detection apparatus 1 with first detection light, a second light emitting unit 102 that irradiates the detection space with second detection light having a different wavelength from a wavelength of the first detection light, a light receiving unit 103 that receives scattered light of the first detection light irradiated from the first light emitting unit 101 due to smoke, outputs a first light receiving signal according to the received scattered light, receives scattered light of the second detection light irradiated from the second light emitting unit 102 with respect to smoke, and outputs a second light receiving signal according to the received scattered light, and an identification unit 107a that identifies a type of smoke present in the detection space on the basis of an output ratio of an output value of the first light receiving signal to an output value of the seco

Abstract: Optoelectronic modules operable to measure proximity independent of object surface reflectivity and, in some implementations, operable to measure characteristics (such as surface reflectivity or absorptivity) of stationary or moving objects are disclosed. The optoelectronic modules are operable to determine, for example, pulse rate, peripheral blood circulation, and/or blood oxygen levels of moving objects, such as the appendage of a user, in some instances. The optoelectronic modules can be used to measure peripheral blood circulation, for example, when a user of the optoelectronic module is engaged in physical activity, such as walking, running or cycling.

Abstract: A photoelectric smoke detector (14) connected to a signal line (12-1) drawn into a warning area from a receiver (10) transmits a fire signal including identification information of smoke caused in detection zones Z1 and Z2. In the detection zones, a sensor (18) for sensing a change of physical phenomenon other than smoke involved in fire is provided, and the sensor (18) is connected to the signal line (12-1) via a relay device (16). The sensor (18) is at least one of a CO2 sensor, a CO sensor, a fire sensor, and a heat sensor. A fire alarm control unit (48) of the receiver (10) causes an alarm to be given, when determining the identification information of the smoke by the photoelectric smoke detector (14) and a sensing value by at least one of the CO2 sensor, the CO sensor, the fire sensor, and the heat sensor.

Abstract: Devices, methods, and systems for a self-calibrating fire sensing device are described herein. One device includes an adjustable particle generator and a variable airflow generator configured to generate aerosol having a particular particle size and optical scatter properties at a controllable density level, a first transmitter light-emitting diode (LED) configured to emit a first light that passes through the aerosol, a second transmitter LED configured to emit a second light that passes through the aerosol, a photodiode configured to detect a scatter level of the first light that passes through the aerosol and detect a scatter level of the second light that passes through the aerosol, and a controller configured to calibrate a gain of the photodiode based on the detected scatter level of the first light, the detected scatter level of the second light, and the controllable aerosol density level.

Abstract: A method of calibrating an optical detector includes positioning a calibration block relative to the optical detector and determining a first calibration point of the detector using the calibration block.

Abstract: A method of calibrating an optical detector includes affixing a calibration material to a first surface of the optical detector and calibrating one or more parameters of the optical detector using the calibration material.

Abstract: A protection device for an oil-smoke sensor has a protection housing having two ends and an inner chamber; the first end having a first opening for receiving a probe of the oil-smoke sensor and in communication with the inner chamber; a second opening is disposed on the second end which is opposite to the first opening and in communication with the inner chamber. Because the probe is sealing mounted in the first opening, the probe will not be directly exposed in oil-smoke flow. The protective device is mounted such that the axial direction of the protective device is vertical to the oil-smoke flow direction. Therefore, the inner chamber of the protection housing has a pressure with respect to the oil-smoke flow that tangentially flows at a high speed, and the oil-smoke can only be diffused into the protection housing, thus, the probe is much less likely to be contaminated.

Abstract: The following is an apparatus and a method that enables the automated collection and identification of airborne particulate matter comprising dust, pollen grains, mold spores, bacterial cells, and soot from a gaseous medium comprising the ambient air. Once ambient air is inducted into the apparatus, aerosol particulates are acquired and imaged under a novel lighting environment that is used to highlight diagnostic features of the acquired airborne particulate matter. Identity determinations of acquired airborne particulate matter are made based on captured images. Abundance quantifications can be made using identity classifications. Raw and summary information are communicated across a data network for review or further analysis by a user. Other than routine maintenance or subsequent analyses, the basic operations of the apparatus may use, but do not require the active participation of a human operator.

Abstract: The hold-open arrester arrangement has a hold-open arrester arrangement having a hold-open function to hold a door open. The arrangement has also an electric release arrangement. The release arrangement is arranged to release the hold-open function in a fire alarm situation. The hold-open arrester arrangement comprises a sliding block and an arrester unit. The sliding block is connectable with a slide rail in a sliding manner and also pivotable connectable to an arm of a door closer. The arrester unit is connectable to the slide rail and has a body, said electric release arrangement, and said hold-open function with the sliding block.

Abstract: A smoke detector with a surface mounted emitter configured to emit light substantially vertically and a surface mounted receiver configured to receive light at an angular distance less than 90° reflected by ambient materials, and a method of operating the smoke detector are provided. The angular distance at which the light is reflected by the ambient materials generates a back scatter effect. The smoke detector includes a housing defining a chamber for receiving the ambient materials, a supporting structure (e.g., a printed circuit board (PCB)) disposed adjacent to the housing, an emitter mounted substantially vertically to an upper surface of the supporting structure, and a receiver mounted substantially vertically to the upper surface of the supporting structure. The smoke detector may also include a controller configured to receive output signals from the receiver (to determine whether a current condition of the chamber indicates a need to trigger an alarm).

Abstract: An apparatus for monitoring an actuator system, a method for providing an apparatus for monitoring an actuator system, and a method for monitoring an actuator system where the has at least one actuator and at least one data output signal. An anomaly detector detects anomalies. A suppressing engine determines time periods in which a control intervention has been performed. In a resulting monitoring signal, only anomalies are indicated which do not overlap with time periods in which the control intervention has been performed resulting in less irrelevant alerts and false positives output to a human supervisor monitoring the actuator system. The apparatus for monitoring a system may be provided with a plurality of actuators that may affect one another over time. The apparatus may be applied to a system of submersible pumps, or a system of conveyor belts.

Abstract: An optical detector device may receive a spectroscopic measurement from a multispectral sensor. The optical detector device may determine, based on the spectroscopic measurement, a particulate size of a particulate. The optical detector device may determine, based on the spectroscopic measurement, an identification of the particulate. The optical detector device may determine, based on the particulate size and the identification of the particulate, that an alert condition is satisfied. The optical detector device may trigger an alert based on determining that the alert condition is satisfied.

Abstract: A smoke detector alarm system configured with improvements that enable remotely positioning a smoke detector battery from a smoke detector while recharging the battery such that there is not a loss of battery power in case of a power outage and the battery replacement needs are reduced.

Abstract: A multi-point detection system includes one or more light sources, one or more light sensors, and a controller. The light sources are configured to emit an array of collimated light beams, and the light sensors define an array of lines of view. Each of the lines of view intersect different ones of the collimated light beams at respective detection nodes. The light sensors are operable to emit sensor signals responsive to received scattered light from interaction of the collimated light beams with an analyte at the detection nodes. The controller is connected to receive the sensor signals and configured to determine from the scattered light whether the analyte contains a contaminant.

Abstract: Analog signal measurement and related circuitry, systems, and methods are disclosed. Circuitry includes timing circuitry configured to assert a first enable signal at a first time and a second enable signal at a second time. The circuitry also includes an operational amplifier circuit configured to enable responsive to the assertion of the first enable signal. The operational amplifier circuit is configured to receive an analog input signal and, if enabled, generate an amplified analog input signal responsive to the analog input signal. The circuitry further includes signal analyzing circuitry configured to enable responsive to the assertion of the first enable signal, compare the amplified analog input signal to one or more threshold values responsive to the assertion of the second enable signal, and generate an alert signal responsive to a determination that the amplified analog input signal falls outside of the one or more threshold values.

Abstract: A smoke detector and method for testing a smoke detector are provided. The smoke detector includes a housing defining a chamber, an emitter, and a receiver. The housing includes an inlet port and an outlet port configured to allow an airflow to pass through the chamber. The emitter is configured to emit light into the chamber. The receiver is configured to receive light reflected by ambient materials in the airflow passing through the chamber. The smoke detector includes an entry point and an exit point, defining a channel therebetween. At least a portion of the airflow passes through the channel. The channel is in fluid communication with a sensor. The sensor is configured to detect at least one of a pressure differential and a mass flow of the airflow. The smoke detector and method for testing the smoke detector enable in situ testing of the smoke detector.