Abstract: A solid state temperature and/or anemometer measuring instrument for a fluid medium such as atmosphere the instrument including a pair of semi conductor junction means such as a zener diode one of which is exposed to fluid flow the other being isolated therefrom and providing outputs which are a function of the temperature of the fluid and a measuring device for measuring the respective outputs the differential being an indication of temperature or fluid speed. Such a device has specific application in an optical air pollution monitor to give a continuous indication of fluid flow thus ensuring that the monitor is sampling fresh batches of fluid from a monitored space.

Abstract: In the known electrical mobility analyzer, a novel means for charged particle detection instead of measuring the low level current carried by the particles is provided. This detection is based on the burst corona occuring from a positive corona electrode applied with a voltage slightly lower than its onset voltage at an instant when a negatively charged particle arrives at the tip of the corona electrode. This detection detects and counts the burst corona pulses produced by the particles negatively precharged.

Abstract: An improved incipient fire detector that employs a sub-micrometer size particle detector of the Wilson cloud chamber type in conjunction with a continuous on-the-fly sequential selector valve assembly and sample gas conduit system for monitoring a plurality of different enclosed spaces (zones). The sampling line for each zone can have up to ten heads, and delivers air or other gaseous atmosphere samples from the respective parts of the zone to the centrally located particle detector at a continuous flow rate of about 14 liters a minute. Each zone line is sampled sequentially by an electronically controlled selector valve assembly for a 15 second interval, once a minute. The cloud chamber particle detector operates at a cycling rate of about once per second and provides a continuous analog voltage corresponding to small particle concentration in the portions of the zone being sampled.

Abstract: A dust detector ring assembly for detecting extremely small quantities of particulate contamination in air being taken into the carburetor of an engine is disclosed. The assembly includes a series of infrared light emitting diodes alternately interposed with a like series of infrared light detecting diodes and arranged in a circle around an interior surface portion of a frame defining a passageway of circular cross-section therethrough. A light beam generated by each of the emitters is directed against a different one of the detectors so that the light beams intersect one another at a common point in the passageway. The sensitivity of the assembly is thus greatest at the common point of intersection of the light beams and decreases proportionally moving away from the intersection point toward the defining surface of the passageway. A flexible circuit board is formed in a circle and is connected to the emitters and detectors. A flat circuit board is connected to the circular circuit board.

Abstract: An apparatus is provided for detecting metal debris particles in a fluid flowing in machinery. The apparatus is adapted to be installed in machinery and has a grid means of electrically insulating material provided with openings of a first type and a second type respectively to allow fluid passage therethrough. Each opening is conductively connected to electric means adapted to provide an electric signal when a conducting particle of metal debris having a predetermined size is trapped in or across any of the openings.

Abstract: A boiler blowdown monitoring system wherein the conductivity of the water in the boiler blowdown line is monitored to determine if it exceeds either a preset maximum or minimum level. The system includes a blowdown sensor, a blowdown valve, a blowdown controller and an interrogation means. The water conductivity is sensed by the sensor located on the blowdown line and transmitted to the interrogation means (e.g. microprocessor) through the boiler blowdown controller. If the sensor senses a water conductivity level above a preselected maximum conductivity level or below a preselected minimum conductivity level after a predetermined time period has passed since the boiler blowdown valve was opened, then an alarm signal is sent to the boiler operator.

Abstract: Airborne dust concentration in a silo or the like is measured by inducing flow in one or more Venturi nozzles (10) located in the area of airborne dust. A triboelectric sensor probe electrode (20) is located at the nozzle inlet section (12) and flow is induced by a feed of inductive air through an annular channel located in the wall of the nozzle downstream of the electrode.

Abstract: An electrostatic probe (27) includes seals (47, 54) adapted to engage sealing surfaces of a borescope access hole provided in the inner and outer walls (24, 25) of the fan duct (22) of a gas turbine engine. The probe includes a center conductor (60), the exposed proximal end of which (31) forms an electrode tip, insulated (35, 36) from an outer metallic wall structure (38, 66), the conductor and wall structure terminating in a coaxial connector 64. A latch means (34, 58) cooperates with a lock pin (76) in one of the fan duct walls.

Abstract: Detecting or measuring of the particle content in gases particularly in exhaust gases of fossil fuels such as soot concentration in exhaust gas of diesel engine and the like, is performed by means of arranging in a gas flow of a sensor which has two electrically heating faces for particle deposition and arranged in two parallel bridge branches of a Wheatstone bridge circuit, wherein one of the heating faces is constantly preheated so that the particle deposition on its surface is at a minimum, voltage or current or their increase are measured in a diagonal branch of the bridge circuit during a heating time period, and a warning signal or a measuring value for the particle content is derived from a maximum of the voltage or current or from a steepness of the voltage or current increase.

Abstract: The invention provides an apparatus and method for measuring the concentration of particles in a gas using an electrode disposed within but electrically insulated from an electrically-conductive conduit member, a current measuring device and means for maintaining the conduit member and the electrode at substantially the same potential. Flow of gas containing charged particles along the conduit induces a current passing from the electrode through the current measuring device. If the concentration of particles in the gas becomes excessive, the current measuring device activates a warning device or takes other action to prevent damage to any gas-consuming device attached to the apparatus. The apparatus might include an optional ionizer upstream of the electrode to charge the particles in the gas.

Abstract: A smoke detector receiving at two input terminals DC power from a remote source not only gives an alarm indication in response to a significant density of smoke, but senses the polarity of DC power at the terminals and generates a secondary signal, distinguishable from the alarm signal, when the polarity of power source is reversed.

Abstract: Oil mist detecting apparatus comprises a measuring chamber which receives air, and oil mist if present, from an engine compartment. The apparatus includes a radiation source which emits light into the measuring chamber, and the radiation sensor which is so disposed as to receive light scattered by oil mist in the chamber. A second radiation source is preferably provided for testing purposes, the second source being arranged to emit radiation directly to the sensor.

Abstract: A device is provided for determining the density or concentration of solid contaminants suspended in a fluid, having an orifice or narrow passage through which the fluid carrying suspended solid contaminants is passed, and monitoring the rate of build-up of the contaminants at the orifice or narrow passage as a function of the density or concentration of the contaminants in the fluid.

Abstract: An air pollutant and/or fire combustion sensing apparatus includes a capacitive sensor having spaced sensing electrodes producing a free space mounted within an environment subject to possible fire or the like. One of the sensing electrodes has an outer dielectric layer for absorbing contaminating gaseous products. The electrodes are connected to a high voltage power source for producing a charged capacitor with a high intensity static electric field of substantially 5.times.10.sup.5 V/M up to the dielectric breakdown of air in the free space or gap. The electric field reacts upon the contaminating gaseous products of combustion and environmental pollution and produces an opposing electric field with a net change in the electric field and the summated voltage appearing across the electrodes. A high input impedance detecting circuit with good electrometer characteristics responds to the change in the field.

Abstract: A method and apparatus for monitoring char flow in a coal gasifier system cludes flow monitor circuits which measure acoustic attenuation caused by the presence of char in a char line and provide a char flow/no flow indication and an indication of relative char density. The flow monitor circuits compute the ratio of signals in two frequency bands, a first frequency band representative of background noise, and a second higher frequency band in which background noise is attenuated by the presence of char. Since the second frequency band contains higher frequencies, the ratio can be used to provide a flow/no flow indication. The second band can also be selected so that attenuation is monotonically related to particle concentration, providing a quantitative measure of char concentration.

Abstract: An electromagnetic system is provided to monitor the activity of a ferrous debris detector of the type which uses electric discharges to automatically disintegrate magnetically concentrated accumulations of micron sized wear particles in hydraulic systems. The data provided are used to detect instances of abnormal wear as shown by either an unusually large number of such discharges or an excessive rate of discharge. Where such abnormality occurs the monitor will provide an audiovisual alarm to warn of the problem in time to prevent catastrophic failure of the system.

Abstract: A fire detection system which includes an environmental sampling assembly upled to a programmable digital processor for detecting a threat of fire and reducing the occurrences of false alarms in a changing environment. The sampling assembly comprises a network of air ducts, a chamber, two sensors, and an exhaust fan. The processor includes two analog-to-digital (A/D) converters, a multiplexed digital summer, short and long-term storage mediums, a signal magnitude comparator, logic circuitry, and a timing generator. The fan continuously draws ambient air through the air ducts and the chamber. Sensors within the chamber sample the air. If the sensors detect particulates of combustion in the air, the sensors provide electrical signals of varying amplitudes, which amplitudes depend on the number and sizes of the particulates being sampled, to the A/D converters of the processor.

Abstract: The invention relates to a dust indicator for detecting the presence of suspended particles, either solid or liquid, in a gas. A concentrated, substantially parallel light beam (1) of suitable wavelength is directed through a measuring chamber (2) containing the gas to be examined. The light beam is surrounded by an internally reflecting elliptical cylindrical reflector (4) in a manner such that the beam (1) coincides with one focal axis (B.sub.1) of the reflector. Arranged in the other focal axis (B.sub.2) of the reflector (4) is at least one light detector (6) with its active surface facing the reflector and the center axis of its field of view directed, preferably perpendicularly, towards the first said focal axis (B.sub.1) along which the beam (1) is directed.

Abstract: Apparatus and methods for detecting an incipient fire condition based on a shift in the size distribution of particles generated by a developing incipient fire condition. Particulate mass concentrations of at least two different particulate sizes are monitored and the ratio of the outputs from the sensing devices is processed as an indication of an incipient fire condition. In another form of the invention, the rate of change of the ratio of the outputs from the monitoring devices is processed as an indication of an incipient fire condition.

Abstract: A protective system for electrical apparatus mounted in a vault which has an opening to the atmosphere. Overheating of the electrical apparatus is distinguished from tobacco smoke, engine exhaust fumes, and other air borne particulates, by an ion chamber monitor and a thermally activated material in the vault which decomposes at a predetermined elevated temperature indicative of overheating. The material is selected to decompose above 300.degree. C. and produce a gas which decreases the self-recombination rate of the ion in the ion detector monitor to increase the ion current. An alarm is generated on a predetermined increase in ion current, instead of upon a decrease, such as caused by particulates.

Abstract: A circuit for a home safety unit having an emergency light system for providing light in the event of a power failure or when a fire is detected, and a fire detection system for providing an audible alarm indicating the existence of a fire. The circuit includes a battery which is constantly being charged and a low voltage responsive system for indicating a low voltage condition on the battery. A latching system causes the emergency light to be turned off when this low voltage condition is reached, and to remain off until the battery is recharged.

Abstract: Disclosed is an ion-controlled device for providing an electrical indication of a specific ion concentration in a fluid. An ion-sensitive membrane is placed over the junction of a gate controlled diode whose impedance is being measured. An external reference electrode is biased such that an inversion layer forms in the semiconductor material near the ion-sensitive membrane. Changes in the concentration of the unknown ion in fluid passing over the ion-sensitive membrane will affect the inversion layer in the gate controlled diode. The change in inversion layer will result in measurable changes in the diodes impedance.