Abstract: Apparatus and method for collecting sidestream smoke produced by a cigarette is disclosed. The apparatus includes a chamber that has upper and lower portions between which smoke may freely move. A cigarette holder is attached to the lower portion so that substantially all of the sidestream smoke produced by the cigarette is released into the chamber means. Smoking means is connected to the cigarette holder means to intermittently draw air through the cigarette and segregate the mainstream smoke from the sidestream smoke. The total relative amount of sidestream smoke may be measured by measuring the opacity of the collected sidestream smoke.

Abstract: An electrooptical system and technique for direct quantitative measurement of the mass concentration of monodisperse aerosols by means of filling an enclosed chamber with a cloud or a sequence of separate clouds of essentially transparent and spherical, aerosolized particles or droplets of known density and known or selectively controlled particle size. While within the confines of the chamber the cloud, or each of the sequence of clouds, of aerosolized particles is maintained in a homogeneous condition and irradiated with a beam of high-intensity and constant wavelength irradiation selected to possess a wavelength to particle size ratio wherein attenuation of the irradiation will be almost exclusively, if not nearly entirely, attributable to optical scattering.

Abstract: A smoke detector utilizing a pulsing light source, a photo-voltaic cell, and an amplifier, in which the total current output on each light pulse is a function of the smoke concentration. In a preferred embodiment of the invention, the amplifier output current resulting from each light pulse is converted into an output signal which has a duration which is a function of smoke concentration.

Abstract: Apparatus is disclosed to accurately measure and analyze multiple component interfering gases which coexist in the stack gas effluent generated from a combustion process which utilizes a non-dispersive, narrowband infrared absorption technique. The apparatus includes a probe in the stack with an optical measurement cavity (34) through which the stack gases are passed. A transceiver (14) mounted to the probe includes an optical portion operatively associated with the measurement cavity including a chopped light source (54), (60), (62) for projecting beams of light into the measurement cavity and a detector (86) for detecting the attenuation of the gases to provide a measure of the extent of absorption of each gas of interest. A control unit, preferably remote from the transceiver, preferably a programmed digital computer, and preferably via a J-box (18) converts the electric outputs to a corresponding % modulation and in turn corrects for temperature, pressure and interference between gases.

Abstract: A smoke detector is disclosed having a radiation source operated in a pulsed mode. Externally of a direct radiation region of the radiation source there is arranged a radiation receiver which, in the presence of smoke or other particles emanating from a combustion process and located in the radiation region, is impinged by scattered radiation and delivers an output signal to an evaluation circuit. The evaluation circuit contains switching elements which, when the number of source output signals or pulses exceeds a predetermined threshold value for the number of source output pulses, delivers an alarm signal. Near to the radiation receiver there is arranged a reference cell in the direct radiation beam of the radiation source, this reference cell controlling the emission of radiation by the radiation source.

Abstract: Apparatus for controllably admitting a sample volume of engine exhaust into a bifurcated, closed-loop opacity chamber and wherein the exhaust sample is controllably directed away from the internal optics via symmetric flow inducing air guides. A pulsed light source is controllably directed through the opacity chamber and exhaust sample and the detected light is compared to a reference level so as to determine a relative measure of the sample's opacity. Attendant control circuitry permits the selected display of corresponding sample opacity and density values.

Abstract: A light extinction type smoke detector which uses simple pulsed light or modulation pulsed light to reduce energy consumption, and precisely discriminates smoke generated by fire from extraneous interruption of the light beam from the light source to the photoelectric element to prevent a false alarm.

Abstract: Apparatus for detecting oil mist or other light-affecting contamination in a fluid comprises a measuring chamber across which a light source directs a beam of light on to a photocell. Solenoid valves each control the connection of a respective inlet pipe (connected, for example, to a particular part of an internal combustion engine being monitored for oil mist) to the measuring chamber. The solenoid valves are operated in sequence so as to admit respective samples of the atmosphere into the measuring chamber where the degree of contamination is detected by the changing photocell output. The samples are drawn into the measuring chamber by suction from a fan unit. The fan unit is also connected by a by-pass chamber and by-pass pipes in the individual valve units to the inlet pipes on the upstream sides of the valves. In this way, the inlet pipes are kept charged with atmosphere from the areas being monitored so that each sample is very rapidly sucked into the measuring chamber when a valve is opened.

Abstract: Smoke detection and disconnection apparatus that includes a housing having an inlet and an outlet for the passage of smoke and a smoke detection chamber located between the inlet and the outlet. The smoke detection chamber has radiation emitting and detecting equipment for the detection of smoke. An external air deflector or smoke concentrator is connected to the housing for increasing the sensitivity of the smoke detection and disconnection apparatus. The smoke detection and disconnection apparatus not only detects smoke but it also disconnects the electrical equipment that is causing the smoke to prevent further damage. In addition, an alarm is sounded to alert personnel that there is a potential fire hazard with respect to the electrical equipment.

Abstract: An optical smoke detector having a conical masking body located directly between a light source and a light receiver. The masking body is provided with a reflecting surface so that rays from the light source are diverted into a reaction zone to supplement direct rays from the light source to the zone. In one embodiment the reflecting surface is cuspidate while in another embodiment a second masking body is added which shadows the light receiver from viewing the base of the first masking body.

Abstract: A photoelectric smoke detector for providing indications of both alarm and trouble conditions is disclosed having a source of light, a detector apparatus having a light responsive device, said detector apparatus providing an output subject to a first change dependent upon the presence of smoke, the smoke detector further having a housing for mounting the source of light and the light responsive device, the housing having light path means for allowing light from the source of light to fall upon the light responsive device, the output from the detector apparatus being subject to a second change dependent upon trouble conditions, a first level sensor responsive to the first change to provide an alarm indication, and a second level sensor responsive to the second change to provide a trouble indication.

Abstract: A method and apparatus for use in an outside collection baghouse to identify defective filter bags. Each filter bag is equipped with a sensing head adjacent the open mouth of the bag. Each sensing head includes a pair of optical fibers having free ends disposed in the path of gas flowing out the bag mouth. Light is applied to one optical fiber in each pair and the amount of light reaching the other optical fiber is sensed to provide a measurement of the amount of light intercepted by particulate matter leaking through the bag.

Abstract: An airborne dust monitor. Photosensitive elements detect a predetermined airborne dust level at a test region adjacent the photosensitive elements. The photosensitive elements are housed within a flue which shields the test region from ambient light while it conducts ambient air through the test region. In a preferred embodiment, the flue is formed of generally vertical sidewall members which define an ambient air passage through the test region, air passage outlets positioned above the test region and a baffle generally at the inlet of the air passage for allowing the entry of ambient air to the passage while blocking light from the test region. A test system may be provided by which a member is selectively positionable within the test region. Preferably, the photosensitive detecting elements include a radiant energy source and an element responsive to that radiant energy, most preferably infrared energy, the photosensitive elements being positioned to minimize dust settlement on the acting portions thereof.

Abstract: A smoke detector which responds to the presence of smoke or other aerosol particles within a smoke chamber. The detector includes a photocell and a pair of light sources, one light source aimed directly at the cell and the other light source shielded from direct illumination of the cell, but aimed at an inspection zone to which the cell is visible. The first light source shines in a generally steady state directly against the cell to bias the cell to a predetermined level. Cyclically, the first light source will be turned off and the second light source will be turned on to illuminate any smoke that may be present in the inspection zone. If smoke is present in excess of that which corresponds to the pre-bias of the cell, the output will rise due to reflection of light from the second light source against the smoke and onto the cell. The output will remain the same if the amount of smoke is equal to the pre-bias and the output will drop if the smoke is less than the pre-bias.

Abstract: An antifouling window assembly in a duct gas monitoring system comprises a mixing chamber positioned between a duct opening and a window unit. Purge gas is introduced into the mixing chamber through an inlet located adjacent the window unit. The velocity of the purge gas is such that laminar flow is established along the surface of the window unit. The purge gas circulates within the chamber and passes into the duct through the duct opening to mix with duct gases and deflect the gases from the mixing chamber.

Abstract: The highly sensitive spectrophone assembly of the subject invention simultaneously and continuously provides an accurate measure of the absorption of electromagnetic radiation by atmospheric gases and particulate matter by providing successive flow through chambers. The gases and particulate matter pass through the first chamber, are directed through a filter where the particulate matter is removed, leaving the gases to flow through the second chamber. The signal representative of the absorption of energy is generated in each chamber and fed into a differential amplifier, to provide an accurate indication of the particulate matter in the atmosphere being monitored. Grounding one side yields a signal attributable to the gaseous absorption.

Abstract: A reflected light optical smoke detector includes a thermistor in series with a light emitting diode connected in parallel to a photo-resistive cell. Alarm circuitry is connected to the photocell having a voltage output which is a function of the presence or absence of smoke in an examination zone illuminated by the light source and visible to the cell. The circuit is temperature-compensated automatically by the thermistor since the thermistor will increase the current to the LED in the event of an increase of ambient temperature. The increase in the LED light output will compensate for the loss of photocell sensitivity in the event of an increase in temperature.

Abstract: A photoelectronic smoke detector has walls around a dark chamber to which smoke, but not light, is admitted, and through which light is directed from a source on a path to a limited area of a chamber wall. A first photocell views light scattered from the through path by particles in the path primarily and also receives background light scattered from the chamber wall outside the limited area. A second photocell is disposed to receive background light substantially only from the limited area and other areas outside the source light path. The first cell produces a first signal in response to background and particle-scattered light. The second cell produces a second signal corresponding to background scatter. The first and second cells, preferably photovoltaic photodiodes, are coupled in opposition in a circuit whose output consequently is substantially independent of the background light.

Abstract: A smoke detector is provided in which two light sources are employed in conjunction with a single photo responsive device and control circuit elements adapted for sequential operation of the light sources. One light source is directed at the photo responsive device to pre-bias the device while the other is directed at a smoke chamber to which the device is exposed. If smoke is present in the chamber, the light from the second source will strike the smoke particles and be reflected against the photo responsive device changing the output thereof. The light sources in one embodiment are timed to operate in a series of pulses and measurements are made on the declining output of the photo responsive device, such that the presence of smoke in the chamber will produce a longer decay time than will occur in the absence of smoke. A timer connected to the circuit measures the decay time and is adapted to generate a signal under the appropriate conditions.

Abstract: A photoelectronic smoke detector has walls around a dark chamber to which smoke, but not light, is admitted, and through which light is directed from an exciter light source on a path to a limited area of a chamber wall. A first photocell views light scattered from the through path by particles in the path primarily to produce an alarm signal, and also receives background light scattered from the chamber wall outside the limited area. A second photocell is disposed to receive background light substantially only from the limited area and other areas outside the source light path. The first cell produces a first signal in response to background and particle-scattered light. The second cell produces a second signal corresponding to background scatter. The first and second cells, preferably photovoltaic photodiodes, are coupled in opposition in a circuit whose output consequently is substantially independent of the background light.

Abstract: An apparatus and a method for standardizing a gas measuring device has a source capable of emitting a beam of radiation aligned to impinge a detector. A housing means encloses the beam. The housing means has a plurality of apertures permitting the gas to enter the housing means, to intercept the beam, and to exit from the housing means. The device further comprises means for closing the apertures and a means for purging said gas from the housing means.

Abstract: A gas analyser of the infra-red radiation absorption type, particularly for measuring the amounts of CO.sub.2 and CO in vehicle exhaust gases, comprises a pair of infra-red radiation sources arranged to direct their radiation along a measurement path and a reference path respectively, the radiation entering each path being periodically interrupted by a rotating commutator. Two measurement chambers for receiving the gas to be analysed and respective detection chambers for CO.sub.2 and CO are alternately disposed along the measurement path, while two reference chambers and two more such detection chambers are alternately disposed along the reference path, corresponding detection chambers being connected to respective differential pressure sensors of the variable capacitance type. The analyser includes a calibration cell containing predetermined concentrations of CO.sub.2 and CO. The cell is selectively interposable in the measurement path, and is connected to a flexible-wall chamber.

Abstract: An apparatus is disclosed for the determination of particle size distribution of a granular material within a measuring channel. The measuring channel has radiation permeable side walls and a granular material is spread out through the measuring channel by a sifting air current in accordance with grain size. A scanning apparatus is movable external to the measuring channel and includes a frame on which is mounted a radiation transmitter and a radiation receiver lying opposite the transmitter. A measuring beam from the transmitter scans through a measuring zone of the measuring channel. The measuring frame is of closed-loop construction and surrounds the measurement channel. With such construction, the frame is not subject to vibration particularly when reciprocated in order to cause scanning movement of the measuring beam.

Abstract: An optical smoke detector comprising a radiation source transmitting radiation throughout a predetermined spatial region and at least one radiation receiver to which there is delivered the radiation scattered by particles located in the radiation region. One or a number of elements conducting radiation by reflection are provided and arranged such that they remove radiation, which has been forwardly scattered at an acute angle with respect to the radiation direction, at a substantially ring-shaped zone about the region of direct radiation and delivers such removed forwardly scattered radiation to the radiation receiver.

Abstract: A smoke detector and housing assembly therefore in which the housing components are designed to allow rapid assembly of the detector with a minimum amount of labor. In a preferred embodiment of the invention a retainer for a photo-cell and light source is provided with a medial portion retaining the photo-cell and portions extending forwardly from the ends of the medial portion for projecting a light beam through the field of view of the photo-cell. The retainer is molded in two similar halves and fastened together after assembly of the photo-cell, light source, and other components therein.A base plate is provided with suitable apertures for receiving the forwardly projecting portions of the retainer so that after assembly they protrude from the forward face thereof. A cylindrical member and cover are mounted on the forward face of the base plate between the forwardly projecting portions of the retainer, forming a dark chamber across which the light beam projects, and into which the photo-cell views.

Abstract: An optical smoke detector has a housing which forms a dark chamber into which light is directed on a path viewed by a photocell. Light scattered from the path by smoke causes the cell to trigger an alarm. The housing includes an interior wall around the dark chamber and an exterior wall exposed to ambient light. A wire mesh extending between offset ports in the exterior and interior walls screens insects from the chamber and obstructs light from passing directly to the interior part.

Abstract: An optical smoke detector having a conical masking body located directly between a light source and a light receiver. The masking body is provided with a reflecting surface so that rays from the light source are diverted into a reaction zone to supplement direct rays from the light source to the zone. In one embodiment the reflecting surface is cuspidate while in another embodiment a second masking body is added which shadows the light receiver from viewing the base of the first masking body.