Abstract: A novel basic allergen/particulate data collection device and a novel multi-function personal air quality management device are disclosed. Both devices include sensor sub-assembly detecting and reporting on allergen/particulate data (preferably, for allergen/particulate with sizes smaller than 5 micron) for an indoor location (where the asthma patient is situated). Both devices are communication enabled to allow the allergen/particulate data to be provided to an air/asthma advice server, to generate air/asthma advice for an asthma patient, taking into consideration the allergen/particulate data as well as air quality data for a surrounding outdoor area of the indoor location. In one embodiment of the basic device, the communication interface is tailored for “harsh environment” local area networking.

Abstract: A method and apparatus for detecting a fluid; said method comprising providing one or more oscillators transmitting electromagnetic energy; providing one or more resonant circuits receiving electromagnetic energy from the oscillators; bringing the fluid and the one or more resonant circuits into contact with each other so that the receptions of electromagnetic energy of the resonant circuits are changed; and detecting changes of the transmissions of the oscillators by changes in one or more characteristics thereof upon the changes in the receptions of the electromagnetic energy of the resonant circuits; and use thereof for the detection of fluid levels, empty containers, and leak of fluids from containers and bodies containing said fluids; e.g. for monitoring collection of drain fluid from a human or for monitoring leak of fluid from a human suffering from urinary and/or fecal incontinence.

Abstract: A sealant stream anomaly detecting assembly for detecting anomalies such as gas bubbles in a high-pressure sealant stream. The assembly includes an ultrasonic transducer supported on a manifold defining a sensing chamber of a fluid channel. The transducer converts electrical voltage pulses into ultrasonic acoustic pulses and propagates the acoustic pulses through the manifold and into the sensing chamber. The transducer also receives resulting echo pulses from a back wall of the sensing chamber and converts the echo pulses into electrical output impulses. A control module including drive electronics is connected to the transducer. The module detects diminished and lost echo pulses by comparing the output impulse strength values for a given fluid passing through the sensing chamber to a known output impulse strength value for that same type of fluid having no anomalies.

Abstract: An apparatus for detecting and containing chemical or biological contaminants. The invention includes one or more optical contaminant detectors, capable of detecting chemical and biological agents. A containment assembly is installed in the duct work of a building, just downstream from the main intake. Air flows linearly through the containment assembly. The air first flows through a first damper, then through the contamination sensor or sensors, and then through a second damper. If a sensor senses a contaminant, a controller shuts off the HVAC system, while simultaneously closing the first and second dampers. The containment assembly is thereby hermetically sealed—trapping any contaminants inside. The sensors and second damper are spaced sufficiently far apart so that no contaminant will flow through the second damper before its closure. The controller can also be configured to alert authorized personnel as to the potential contamination.

Abstract: A system and technique for detecting the presence of foreign material is presented. An ultrasound transmitter interrogates the bulk material and an array of detectors receives the off angle ultrasound scattering response of the bulk material. The presence of foreign material is determined when the off angle scattering response exceeds a predetermined threshold. The technique is especially suitable for the detection of bone in meat.

Abstract: A respirator system (10; 100) for a worker in an environment with hazardous airborne contaminants comprises a respirator (12, 112), a helmet (14, 114), a camera (40, 140), and a gas sample analyser (16, 116) capable of analysing samples of gas from within the respirator and in the immediate area near the user. An RF emitter (20, 120) sends a signal to a remote receiver (24, 124). The emitted signal is a real time view through the camera (40, 140) and overlaid on that is a graphical representation of the protection factor being achieved by the respirator. The system (100) may also have a data storage device (162, 170) to store data such as how protection factor varies with time and may have a position sensor (160). The provision of the position sensor (160) allows a map of contamination levels with position to be built up as a user moves around a site.

Abstract: A novel basic allergen data collection device and a novel multi-function personal asthma management device are disclosed. Both devices include sensor sub-assembly detecting and reporting on allergen data (preferably, for allergen with sizes smaller than 5 micron) for an indoor location (where the asthma patient is situated). Both devices are communication enabled to allow the allergen data to be provided to an air/asthma advice server, to generate air/asthma advice for an asthma patient, taking into consideration the allergen data as well as air quality data for a surrounding outdoor area of the indoor location. In one embodiment of the basic device, the communication interface is tailored for “harsh environment” local area networking. When combined with its streamlined functionality, the device is particularly suitable (especially in terms of economics) for multiple deployment (along with a “base station”), such as in the case of an home application.

Abstract: A microcontroller establishes normal operation and vacuuming operation profiles of time and vacuum for a pool or spa circulating pump. A user slightly adjusts the levels of vacuum within a predetermined range for storing a vacuum profile envelope within the memory for a normal pump circulating operation and a vacuum profile envelope within the memory for a vacuuming operation. A comparator compares actual inputs of time-from-start and pump vacuum with the normal operation envelope during normal operation of the circulating pump. The comparator compares real time inputs of the sensed vacuum and the time-from-start when the controller is in the vacuuming mode with the vacuuming envelope stored in the memory. Deviations of the sensed pressures from the envelope cause pump shutdown and alarm activation. A calibration switch is positioned inside a locked weatherproof control enclosure.

Abstract: This invention provides a particle size distribution measuring apparatus, which has a function of informing an operator of a procedure of validation work of the particle size distribution measuring apparatus. A storage medium which records validation data providing a procedure of validation work for the particle size distribution measuring apparatus and a control unit which has a validation help function which successively reads a validation procedure from the validation data and controls the particle size distribution measuring apparatus according to a measuring procedure without any operation by an operator in the validation procedure while teaching the operator a work procedure requiring an operation by the operator.

Abstract: A gas detection system for use in multiple zones. The system includes a plurality of gas sensor assemblies, a central control, and an alarm. The alarm includes a plurality of indicator lights that are disposed at the central control, with a respective indicator light being in electrical communication with an associated gas sensor so as to allow the respective indicator light to illuminate when the associated gas sensor detects the gas and provide a visible alarm that is detected from a central location remote from the plurality of gas sensor assemblies, and a sound generator that is disposed at each sensor assembly, with a respective sound generator being in electrical communication with an associated gas sensor so as to allow the respective sound generator to activate when the associated gas sensor detects the gas and provide an audible alarm that is detected at the associated gas sensor.

Abstract: A novel air/asthma advice method and apparatus for providing air/asthma advice to an asthma patient, taking into consideration indoor allergen as well as outdoor air quality conditions, is disclosed. Allergen data (preferably for allergen with sizes smaller than 5 micron) for an indoor location (where the asthma patient is situated) are collected, and provided to a geographically removed air/asthma advice server. The server, in turn, retrieves air quality data for a surrounding outdoor area of the indoor location (from either a private or an independent source), and generates an allergen advice response for the asthma patient. The air/asthma advice is generated based at least in part on the received allergen data and the retrieved air quality data. The air/asthma advice may be delivered to the asthma patient in any one of a number of forms (a beeping alert, a pager, fax, email or voice message, and so forth). Various other alterations and modifications under different embodiments are also disclosed.

Abstract: A light emitting diode 1 and a condenser lens 2 are arranged in an optical axis direction. In the light emitting diode 1, a cover 4 having a tip end lens 5 is attached to one side of a main unit base 9, a light emitting chip 6 is supported by a bonding wire 8 drawn out from the body base 9 inside the cover 4, and a reflector 7 is placed behind the light emitting chip 6. With respect to a first light source of the light emitting chip 6, the position where light which is forward reflected by the reflector 7 impinges on the tip end lens 5 is set as a virtual second light source 10, and the focal point of the condenser lens 2 is set at the position of or in the vicinity of the position of the second light source 10.

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: An apparatus for dispensing particles includes a storage tank for containing particles to be dispensed a metering mechanism for transferring particles from the storage tank and an air distribution system for receiving particles from the metering mechanism. The air distribution system includes a bank of tubes for transporting particles in a flow of air having a flow rate, and a damper mechanism at the bank of tubes for selective control of the flow rate within the bank of tubes. The apparatus for dispensing particles also includes an air flow source for providing a flow of air to the bank of tubes, a sensor located at each tube for providing a sensor output signal indicative of a value of a flow characteristic, and a controller operably connected to the sensors and to the damper mechanism.

Abstract: An alarm system for portable chemical monitors comprising a housing configured for attachment to the portable chemical monitor having a twist lock mechanical connector capable of connecting to the portable chemical monitor, at least three pins mounted within the housing that are capable of inserting into the portable chemical monitor, a circuit board electrically connected to the pins and capable of receiving electrical signals from the chemical monitor, and a ceramic disk supported within the housing having an indicator means for generating vibrational movement that provides a audible sound. A method for monitoring for the presence of chemical agents is disclosed.

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 sensing device in which a high frequency signal is transmitted from an oscillator to a sensor through a transmission path, a reflection signal generated according to a variation of an impedance of the sensor sensing the presence or absence of an article is detected by a reflected wave sensor, and the presence or absence of the article is detected by the presence or absence of the reflection signal and a level of the signal, whereby the presence or absence of an article other than metal and the kind of the article can be detected regardless of whether a container holding the article is transparent or opaque.

Abstract: An alarm system 10 for the fill tube 20 of an engine oil fill tube for heavy equipment to warn the operator of the equipment that an attempt has been made to sabotage the equipment by the introduction of metal particles 100 through the inlet end 22 of the engine oil fill tube 20. The alarm system 10 includes a non-metallic electrical contact member 42 having a magnetic tip 43 disposed proximate to the angled face 41 of a plate member 48 disposed within the fill tube 20. The accumulation of metal particles 100 on the plate member 40 will establish an electrical connection between the plate member and the magnetic tip 43 to activate one or more alarm members 50, 70.

Abstract: An allergen particle detecting apparatus has a sample area through which environmental air is directed. A light beam is directed through the air sample so that portions of the beam will be scattered if any particles are present in the path of the beam. A beam blocking device on the opposite side of the air sample is arranged to block all light except light scattered in a predetermined angular range corresponding to a predetermined allergen particle size range. Light transmitted through the blocking device is detected by a light detector and an alarm output signal is produced if the detected amount of light is above a predetermined level.

Abstract: A light beam is directed from a light source through an air sample so that portions of the beam will be scattered if any particles are present in the path of the beam. A beam blocking device on the opposite side of the air sample is arranged to block all light except light scattered in a predetermined angular range corresponding to a predetermined allergen particle size range. A light focusing lens in front of the light source is arranged to focus the unscattered part of the light beam onto the blocking device. Light transmitted through the blocking device is detected by a light detector and an alarm output signal is produced if the detected amount of light is above a predetermined level. The signal may be used to activate filtering or air conditioning devices.

Abstract: An allergen particle detecting apparatus has a sample area through which environmental air is directed. A light beam is directed through the air sample so that portions of the beam will be scattered if any particles are present in the path of the beam. A beam blocking device on the opposite side of the air sample is arranged to block all light except light scattered in a predetermined angular range corresponding to a predetermined allergen particle size range. Light transmitted through the blocking device is detected by a light detector and an alarm output signal is produced if the detected amount of light is above a predetermined level.

Abstract: The present invention is a contamination measuring device and method of using the same according to a Chemical Mechanical Polishing (CMP) brush cleaner equipment/technology. A collection device is mounted in a brush cleaning device for collecting effluent which flows off of a wafer. The effluent is passed to a particle counter which measures the contamination levels of the effluent. A computer stores the data collected by the particle counter and computes the particles per liter of effluent and provides real time data. The contamination of the effluent corresponds to the contamination of the brushes in the cleaning device and therefore is means for predicting when the brushes in the cleaning device should be replaced.

Abstract: An allergen particle detecting apparatus has a sample area through which environmental air is directed. A light beam is directed through the air sample so that portions of the beam will be scattered if any particles are present in the path of the beam. A beam blocking device on the opposite side of the air sample is arranged to block all light except light scattered in a predetermined angular range corresponding to a predetermined allergen particle size range. Light transmitted through the blocking device is detected by a light detector and an alarm output signal is produced if the detected amount of light is above a predetermined level.

Abstract: A probe rod is provided with sensor housings, pipe sections, and joint sleeves all having a common outer diameter. The sensor housings and joint sleeves are threadably connected to the various pipe sections. The threadable connections have a double seal using an O-ring and threading paste that ensure a gas tight seal while being easy to assemble. Pressure and temperature sensors are mounted within the sensor housings. Output leads from the sensors are threaded through the pipe sections and through throughways in the sensor housings and joint sleeves to a circuitry box mounted on the top of the probe rod. The circuitry box contains electronics for processing signals generated by the sensors and for transmitting the results to a remote location.

Abstract: An apparatus for the detection and identification of metal particles, coolant or water in engine oil or hydraulic fluid. The apparatus comprising means for generating a high frequency oscillating field within the fluid, means for generating an electric field within the fluid, means for measuring the real and imaginary part of the complex impedance associated with the interaction of the electric field and the fluid, and means for determining at least one of the presence, the absence or the variation of metal particles, coolant or water in the fluid based upon the impedance measured. The high frequency oscillating field has a frequency range of approximately 2 megahertz to 10 gigahertz. Also, apparatus for the detection and characteristic identification of contaminants in engine oil or hydraulic fluid is provided.

Abstract: An apparatus is disclosed for continuously sampling, at a point downstream of the air cleaner, the normally clean air entering an air induction system of a diesel engine to produce a signal indicating a leakage malfunction condition in the air induction system by measuring dust/particulate matter. The disclosed apparatus includes an arrangement in the form of a sample collector assembly for obtaining a representative sample of leakage particulates within the diesel engine intake system, a measurement assembly for the quantification of the dust/particulates by optical methods, a signal conditioning assembly (200), a processor (300), and a remote annunciation assembly (400).

Abstract: The present invention is a contamination measuring device and method of using the same according to a Chemical Mechanical Polishing (CMP) brush cleaner equipment/technology. A collection device is mounted in a brush cleaning device for collecting effluent which flows off of a wafer. The effluent is passed to a particle counter which measures the contamination levels of the effluent. A computer stores the data collected by the particle counter and computes the particles per liter of effluent and provides real time data. The contamination of the effluent corresponds to the contamination of the brushes in the cleaning device and therefore is means for predicting when the brushes in the cleaning device should be replaced.

Abstract: An improved method and apparatus for monitoring, in real time, the quality of a flowing fluid stream and of automatically taking samples therefrom when the level of particulate matter in the flow stream exceeds an acceptable limit for a predetermined period of time. The apparatus includes a particle monitor and at least one three-way valve electronically linked via a programmable logic controller to the particle monitor. Not only is the latter an instrument for continuously measuring, on-line, numbers known as particle indices which are indicative of particulate matter concentrations in the flow stream, but also the particle monitor generates electronic signals. Both these signals and the particle index are proportional to fluctuations in the intensity of a light beam traversed by particles which are present in a portion of the flow stream during a fixed interval of time. Importantly, the particle monitor can detect relatively short-lived "spikes" in the level of 0.

Abstract: Apparatus for monitoring particles in fluid systems in which a detector has electrical contacts that are bridged by particles captured from suspension in the fluid. Upon detection of a particle, a control microprocessor stores a predetermined quantity of electrical energy on a capacitor, which is then discharged through an inductor to burn off the particle at the detector. The burn-off charge and return lines from the charge storage capacitor are un-grounded, and are connected by respective electronic switches through relay contacts to the conductors connected to the chip detector. The relay contacts are also connected to the inputs of a differential amplifier for detecting presence of a chip bridging the detector contacts and monitoring continuity of the conductors to and from the detector. The relay is powered by system voltage, and in the event of system power failure connects the chip detectors directly to warning lamps on an operator panel.

Abstract: A sensor for monitoring a cooling liquid circulating in a circuit of a heat exchanger of an automobile, for example, includes a support for mounting the sensor on a pipe of the circuit so that the liquid is in contact with at least a part of the sensor, a corrodible membrane in contact with the liquid, and a visual indicator reacting to the degree of corrosion of the liquid. The visual indicator includes a piston movable under the combined effect of the breaking of the corrodible membrane and of the pressure difference between inside and outside of the pipe, at least one seal mounted on the movable piston, and the visual indicator protruding from the pipe and/or from the support when the membrane is corroded.

Abstract: A device for the reliable detection of air or air bubbles in transparent or translucent tubing carrying a fluid which includes a transmitter element for transmitting a light beam to the fluid contained in a large-bore thin-walled transparent tubing, and a pair of first and second light receiver devices for receiving reflected and transmitted light emitted from the transmitter element and which is incident upon the fluid conducting tubing. The light transmitter and receivers are located within a body member around the fluid conducting tubing. Also, an acrylic optical spacer which has a passage for accommodating the tubing is located within the body member. One light receiver is disposed at a 90.degree. angle in relation to the optical axis of the transmitter, while the other receiver is arranged at a 180.degree. angle. Outputs of the light receivers are applied to a processor, which processes the light receivers outputs to detect air in the tubing.

Abstract: An apparatus for detecting particles within a hydraulic system having a hydraulic line includes a capacitor formed by a pair of electrodes. A charging circuit produces a charging current of constant magnitude. The charging current is used to charge the capacitor to a predetermined voltage. A timing circuit measures the elapsed time between the time at which the charging circuit begins to produce the charging current and the time at which the capacitor has been charged to the predetermined voltage. The timing circuit produces a pulse width modulated signal. The magnitude of the pulse width modulated signal is indicative of the time difference. A controller receives the pulse width modulated signal and detects particles by comparing the duration of each pulse with a reference pulse.

Abstract: An allergen particle detecting apparatus has a passageway through which environmental air is directed. A light beam is directed across the passageway so that portions of the beam will be scattered if any particles are present in the path of the beam. A beam blocking device on the opposite side of the passageway blocks any non-scattered portion of the beam while transmitting any scattered portions of the beam along a light path in the apparatus. Any light scattered by allergen size particles will be traveling in a predetermined angular range, and a pinhole device is positioned in the light path so as to transmit only light traveling in that angular range. Light transmitted through the pinhole device is detected by a light detector and an alarm output signal is produced if the detected amount of light is above a predetermined level.

Abstract: Methods, circuits, and kits for converting battery powered smoke detectors to AC power include a power converter which converts standard household AC voltage to a DC voltage suitable for use by a battery powered smoke detector and a battery clip connector for connecting the power converter to the battery clips of a battery powered smoke detector. According to one embodiment of the invention, a light emitting diode is coupled to the battery clip connector to indicate the presence or absence of DC voltage at the smoke detector. According to another embodiment of the invention, several battery powered smoke detectors are coupled to a single power converter. In yet another embodiment of the invention, several battery powered smoke detectors are provided with an AC power supply having an automatic battery back-up power supply. Preferred aspects of the invention include: providing the battery backed-up AC power supply with a battery tester and providing fuses for each smoke detector and for the battery.

Abstract: A data display unit for a bicycle includes a means for determining and displaying an operational data signal in a normal operating mode and a workout data signal of a workout window mode having predetermined data information including time, distance, average and maximum speed. The unit is configured to calculate and display the predetermined information of the operational data signal information and to allow for the manual actuation to begin separate calculation, display and resetting of the predetermined information of the workout data signal. The display includes a liquid crystal display for displaying separately operational data signals and workout data signals.

Abstract: A smoke detector unit with a fan that creates an airstream which flows through a smoke detector. Both the fan and the smoke detector are located within a housing that is mounted to the fuselage of an airplane. The smoke detector generates an output signal that is provided to an indicator when a threshold level of smoke is detected. The output signal is typically latched by a relay that is also located within the housing.

Abstract: An improved method of monitoring condensate quality in a condensate return system and of controlling the level of particulate matter in the condensate flow so that when this level exceeds an acceptable limit, valves for discharging the condensate flow from the system open automatically or, alternately, an alarm is sounded. Utilization of the method facilitates the conservation of hot steam condensate for reuse in a boiler while preventing water contaminated with particulate matter from returning to the boiler, thereby protecting it from certain types of deposits and corrosion. The improved method includes measuring, on a continuous basis, relative numbers of particulate-type impurities under conditions in which rust or other particles large enough to block flow into a particle counter can be produced in sudden surges. Tests show that a suitable instrument for measuring the impurities under such conditions is a particle monitor.

Abstract: The application describes a method and apparatus for detecting fire. The apparatus includes a fire detector and a mounting means adapted for attachment to both existing structures and new construction in such a manner as to not protrude into the interior spaces of structures. The method includes the steps of providing a fire detector and recessing the detector into the walls of the structure providing power to the detector and monitoring the detector.

Abstract: A smoke detecting system monitors smoke from different monitored areas. A main system fan is energized to draw air from all the monitored areas through a smoke detecting unit via individual pipes and via a location unit. When smoke is detected, a control unit produces an indication. In addition, it energizes a sequencing unit which switches off the main fan and then sequentially and individually energizes small fans, each of which draws air through a respective one of the individual pipes and feeds it through the smoke detection unit. When the small fan corresponding to the pipe connected to the particular one of the monitored areas from where the smoke originates is energized, there will be an increase in the output of the smoke detector. This is detected by the control unit which causes the sequencing unit to identify this monitored area on an indicator.

Abstract: A mobile fire detecting system for detecting fire conditions at the incipient stage before visible smoke has been released having an air sampling fire detector mounted to a cart supported by wheels. A tubular network in communication with the air sampling detector has a manifold enclosed by a box with four sensing hoses releaseably connected to the lateral outlets of the manifold and a telelscoping mast supporting the manifold to position it at selectable heights. Four sampling heads are connected to the other ends of the sensing hoses and are peripherally spaced equally so that the maximum area is sampled for air to detect fire conditions.

Abstract: An air cleaner with a smoke alarm unit for a forced air recirculating system is disclosed. The smoke alarm unit is housed within a module that fits within the frame of the air cleaner with minimal impact on the cleaning ability of the cleaner. In a preferred embodiment of the invention, a battery capacity tester and air cleaner functionality detector are included in the module. Signals from the battery tester and functionality detector are used by the smoke alarm unit to drive an alarm generator with different signals to produce distinguishable alarms for a smoke condition, low battery condition, and an air cleaner failure. A control unit may receive any of the alarm conditions to execute different control actions in the forced air system.

Abstract: An air cleaner with a smoke alarm unit for a forced air recirculating system is disclosed. The smoke alarm unit is housed within a module that fits within the frame of the air cleaner with minimal impact on the cleaning ability of the cleaner. In a preferred embodiment of the invention, a battery capacity tester and air cleaner functionality detector are included in the module. Signals from the battery tester and functionality detector are used by the smoke alarm unit to drive an alarm generator with different signals to produce distinguishable alarms for a smoke condition, low battery condition, and an air cleaner failure. A control unit may receive any of the alarm conditions to execute different control actions in the forced air system.

Abstract: The blockage module is designed to be mounted on air seeder seeding equipment. Piezoelectric sensors extending into the flow tubes monitor flow by producing high frequency ringing signals when struck by seeds. During a calibration step, the module will monitor each sensor and adjust the gain of the signal until the number of seed hits per second above a fixed voltage threshold is near a predetermined value. Each sensor connected to the module will be similarly calibrated, and the calibrated gain and hit rate will be stored. It has been found that if a blockage or partial blockage occurs under these calibrated conditions, the number of hits above the fixed voltage threshold will be sharply reduced. The reduced hit rate is compared to the calibrated hit rate, and an alarm is generated if the reduction is great enough. Because the reduced hit rate is immediately detectable, the response time to report a blockage is very short.

Abstract: Reliability of bubble or particle detection in a flowing fluid is improved using a pulsed doppler frequency detector. When an echo signal is received, impliedly indicating the existence of a bubble or particle in the carrier fluid, then, based on the flow rate of the carrier fluid, a predetermined time interval is established following a second interrogating pulse during which the second interrogating pulse would be predicted to produce an echo if the first echo did, in fact, represent a real bubble or particle in the fluid. Detection of the second echo during this time interval confirms the existence of the bubble or particle. For fluid flows with cross section velocity profiles that are not constant, e.g. laminar flow, a plurality of different predicted time intervals are established for different points in the velocity profile spaced radially from the fluid conduit and multiple sensing cycles are employed to thereby detect bubbles or particles at different radial positions in the fluid cross section.

Abstract: An allergen detector and allergen detection method for sampling the environment where the detector is located and providing an alarm indication when allergen particulates exceed a predetermined level. The invention comprises a housing having a passageway formed therethrough with a fan disposed in the passageway that is responsive to a flow control signal for creating air flow in a first direction through the passageway. At least one filter is disposed in the passageway for removing particulates larger than allergen particulates in air flowing through the passageway in the first direction. An allergen particulate detector is disposed in the passageway downstream of the filter, with respect to air flow in the first direction, for detecting allergen particulates in the air flowing through the passageway and for providing a corresponding detection signal.

Abstract: In acoustic level sensing apparatus, in which pulses of acoustic energy are transmitted by an electrically energized transducer towards a surface to be sensed, and the electrical output from the transducer following the pulse is digitized and analyzed to detect a return echo from the surface, so as to produce a digitized echo profile. The digitzed echo profile is enhanced by removing narrow peaks likely to correspond with certain types of spurious echo, and narrow valleys which may represent fragmentation of a wanted echo. Echoes are identified by comparing the profile with a time varying threshold generated derived from a linear regression performed on part of the threshold, various different types of comparison being performed and their results combined prior to selecting the most likely true echo on the basis of the combined results.

Abstract: Method and apparatus for sampling the gaseous medium of a zone or area to determine the concentration, or changes in concentration, of submicron particles suspended in the gaseous medium of that area or zone using an elongated cloud chamber. A light source and a phototransistor are disposed in the cloud chamber and spaced apart so as to be electronically responsive to varying levels of light. A microprocessor is connected to a programmable memory EPROM and has pre-programmed data instructions on particle concentration levels. The EPROM sequences the microprocessor to operate the valves that sequentially sample the gaseous medium in the cloud chamber, and opens the exhaust valve in the cloud chamber to create a condition of reduced gas pressure therein. The sample of gaseous medium containing submicron particles then precipitates or condenses a portion of the cloud in the chamber in proportion to the concentration of the particles.

Abstract: An improved detector and alarm circuit for use with electric apparatus which is connected to power lines and where the body of the apparatus is insulated from ground is disclosed. This circuit varies the response time of an alarm in accordance with the magnitude of a sensed voltage thereby reducing the response time as the potential danger increases.

Abstract: In acoustic level sensing apparatus, in which pulses of acoustic energy are transmitted by an electrically energized transducer towards a surface to be sensed, and the electrical output from the transducer following the pulse is digitized and analyzed to detect a return echo from the surface, so as to produce a digitized echo profile. The digitized echo profile is enhanced by removing narrow peaks likely to correspond with certain types of spurious echo, and narrow valleys which may represent fragmentation of a wanted echo. Echoes are identified by comparing the profile with a time varying threshold generated derived from a linear regression performed on part of the threshold, various different types of comparison being performed and their results combined prior to selecting the most likely true echo on the basis of the combined results.

Abstract: An analog ASIC (Application Specific Integrated Circuit) circuit has a power control section, a conductivity filter testing section, a light emitting diode (LED) driving section, and a bias section. The LED driving section is responsive to the conductivity filter testing section for indicating when the filter should be replaced. The power control section, conductivity filter testing section, LED driving section, and bias section are all operated in a controlled timed relation by a digital ASIC logic system to minimize power use.