US3028490A - Apparatus responsive to the composition of a gaseous medium - Google Patents

Apparatus responsive to the composition of a gaseous medium Download PDF

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US3028490A
US3028490A US714341A US71434158A US3028490A US 3028490 A US3028490 A US 3028490A US 714341 A US714341 A US 714341A US 71434158 A US71434158 A US 71434158A US 3028490 A US3028490 A US 3028490A
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chamber
gas
anode
grid
composition
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US714341A
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English (en)
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Guilleux Robert
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A RESPONSABILITE LA DETECTION ELECTRONIQUE FRANCAISE Ltee Ste
SARL LA DETECTION ELECTRONIQUE
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SARL LA DETECTION ELECTRONIQUE
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C51/00—Shaping by thermoforming, i.e. shaping sheets or sheet like preforms after heating, e.g. shaping sheets in matched moulds or by deep-drawing; Apparatus therefor
    • B29C51/08—Deep drawing or matched-mould forming, i.e. using mechanical means only
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/62—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating the ionisation of gases, e.g. aerosols; by investigating electric discharges, e.g. emission of cathode
    • G01N27/64—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating the ionisation of gases, e.g. aerosols; by investigating electric discharges, e.g. emission of cathode using wave or particle radiation to ionise a gas, e.g. in an ionisation chamber
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/62—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating the ionisation of gases, e.g. aerosols; by investigating electric discharges, e.g. emission of cathode
    • G01N27/64—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating the ionisation of gases, e.g. aerosols; by investigating electric discharges, e.g. emission of cathode using wave or particle radiation to ionise a gas, e.g. in an ionisation chamber
    • G01N27/66—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating the ionisation of gases, e.g. aerosols; by investigating electric discharges, e.g. emission of cathode using wave or particle radiation to ionise a gas, e.g. in an ionisation chamber and measuring current or voltage
    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B17/00—Fire alarms; Alarms responsive to explosion
    • G08B17/10—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means
    • G08B17/11—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means using an ionisation chamber for detecting smoke or gas
    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B17/00—Fire alarms; Alarms responsive to explosion
    • G08B17/10—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means
    • G08B17/11—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means using an ionisation chamber for detecting smoke or gas
    • G08B17/113—Constructional details
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J41/00—Discharge tubes for measuring pressure of introduced gas or for detecting presence of gas; Discharge tubes for evacuation by diffusion of ions
    • H01J41/02—Discharge tubes for measuring pressure of introduced gas or for detecting presence of gas
    • H01J41/04—Discharge tubes for measuring pressure of introduced gas or for detecting presence of gas with ionisation by means of thermionic cathodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J41/00—Discharge tubes for measuring pressure of introduced gas or for detecting presence of gas; Discharge tubes for evacuation by diffusion of ions
    • H01J41/02—Discharge tubes for measuring pressure of introduced gas or for detecting presence of gas
    • H01J41/08—Discharge tubes for measuring pressure of introduced gas or for detecting presence of gas with ionisation by means of radioactive substances, e.g. alphatrons

Definitions

  • This invention relates to apparatus responsive to the composition of a gas, of the type wherein variations in said composition induce corresponding variations in the ionizing current flowing through an ionizing chamber exposed to the gas being tested.
  • Apparatus of this type have applications in various fields, e.g. as fire detectors, control of furnace combustion, automatic control of chemical processes, and the like.
  • a general object of this invention is to provide improved apparatus of this type which will be simple, accurate and reliable and will have a more rapid response than obtainable heretofore;
  • a first ionization chamber through which the gas is caused to flow and containing a sourc of radiations such as a small body of radio-active material in the path of said gas and an ion-collecting electrode or anode positioned beyond said source so that the ions generated in the gas flow by the radiation source are collected by said electrode.
  • a sourc of radiations such as a small body of radio-active material in the path of said gas and an ion-collecting electrode or anode positioned beyond said source so that the ions generated in the gas flow by the radiation source are collected by said electrode.
  • a secondary ionization chamber defining a sealed enclosure containing a reference gas therein has an electrode thereof connected in series with the output electrode of the primary chamber, so as to provide on a junction common to both said electrodes a reference potential which may be made to represent the departure of the condition of the gas being tested from a reference condition.
  • This potential can be utilized in a suitable controller transducer circuit to provide an indication of the tested gas composition or to operate any desired controlled means, such as warning apparatus and equipment adapted to restore the gas to the prescribed condition.
  • This potential may also be similarly utilized to provide an indication of both the tested gas composition and to operate any desired controlled means.
  • the primary ionization chamber is required to be installed at a location remote from the space in which the gaseous atmosphere is to be controlled, and is connected with said space by way of a conduit, and a fan is provided for impelling the gas stream from the space to the chamber. Difiiculties have been encountered in the past in installations of this sort because, if the rate of flow of the gas through the conduit is slow, there is a delay or leg in the response of the apparatus corresponding to the time required for the gas to pass from the space to the chamber and such delayed response can have serious consequences as in cases where the system is used, for example, as a fire-alarm or for automatic process control.
  • the invention provides an electrode in the form of a screen grid which is carried to a negative voltage potential relative to the ion collector electrode and is disposed beyond the latter in the direction of flow. There is provided in this way an electrostatic barrier which acts to repel the negative ions towards the collector electrode thereby ensuring that all said ions are collected regardless of the rate of gas flow, so that uniform indications are produced.
  • the ionization chamber usually comprises a cathode in the form of a conductive cylinder coated with radio-active material,
  • ionization chambers so constructed are apt to respond to stray or parasitic radiation fields from external sources, and it is therefore another object of this invention to remove this additional cause of unreliability.
  • this object is achieved by the provision of an ionization chamber comprising a conductive outer casing maintained at a fixed reference potential, e.g. ground, and a coaxial inner cylinder of insulating material serving as a support forthe electrodes of the chamber.
  • the invention provides apparatus of the type specified comprising a first ionization chamber including a conductive outer cylinder maintained at ground potential, an insulating inner cylinder coaxial therewith, a cathode, a radiant source and an anode all supported in the chamber from said insulating cylinder, a screen grid supported from said insulating cylinder in a downstream position relative to said anode and maintained at an adjustable potential negative with respect to the anode potential, means for delivering gas to be tested through said chamber, a scaled reference ionization chamber having a cathode electrically connected to a common junction with theanode of the first chamber, so as to provide at said junction a potential depending on the composition of said gas, and control circuit means connected with said junction and responsive to said potential for operating output apparatus in accordance therewith.
  • control circuit means preferably includes a multielectrode electron tube comprising a cathode, a first grid positively biassed with respect to the cathode and a second or control grid beyond the first grid biassed negatively so as to maintain the tube beyond cut-off, the potential from the above mentioned junction being applied to said value.
  • FIG. 1 is a diagrammatic view, partly in simplified axial cross section and partly in schematic form, of apparatus according to the invention.
  • FIG. 2 shows fragmentarily a modified form of the ionization chamber according to the invention.
  • an improved ionization chamber 1 comprises an outer tubular member 4 of electrically conductive material through which a stream of gas to be tested, i.e. air from an enclosure that is to be supervised for fire hazard, is blown by means of an electrically operated fan 3.
  • a stream of gas to be tested i.e. air from an enclosure that is to be supervised for fire hazard
  • the fan 3 may be disposed at a point remote from the ionization chamber 1 at the far end of a conduit connecting said chamber with the premises being supervised.
  • the ends of the tubular member 4 have protective screens 5 and 6 secured across them for preventing the ingress of dirt and other foreign objects into the ionization chamber.
  • Internally lining the tubular shielding member 4 is a tubular member 7 made of insulating material and serving as a support for the electrodes in the chamber.
  • the said electrodes include a cathode 8, which may be provided in the form of a grid, an ion collector electrode or anode 9 which is supported from member 7 by means of an insulator support 10, and a screen grid electrode 11.
  • a source of radiations such as a strip 12 coated with radium salt or other source of predominantly alpha particles.
  • a rod 13 made of suitable metallic material for arrestin the radiations, and adjustable in position in front of the emissive surface of the source 12, operable from outside the chamber by means of a knurled head and screw threads thereon.
  • a heating filament 14 is provided near said surface and parallel thereto and is connected with a source of voltage so as to be raised to a temperature slightly above ambient.
  • the screen grid electrode 11 is connected with a negative potential relatively to the anode 9.
  • the function of electrode 11 is to repel back towards the collector anode 9 any negative ions that may be carried with the gas flow past said anode, and to collect any positive ions formed in the gas flow due to bombardment by the alpha particles.
  • the degree of ionization and the ionizing current are maintained substantially constant between electrodes 8 and 9 for high and variable values of the gas flow velocity.
  • Optimum operating conditions are obtained by a proper adjustment of the voltage difference between electrodes 9 and 11, as well as by appropriate shaping, dimensioning and spacing said electrodes.
  • the electrode 11 is mounted in a slidable sleeve 15 the axial position of which within the insulating support member 7 can readily be adjusted by means of a knob 16 formed at the Outer end of a stem projecting through a helical guiding slot 17 formed in said member.
  • the repelling or stabilizing electrode 11 instead of being in the form of a grid as shown, may be provided in the form of an emissive filament or cathode operated to create a space charge in the area beyond (to the right of) the collector anode 9 with similar beneficial effects to those indicated above for the case where electrode 11 is a grid.
  • a reference ionization chamber 2 is provided in the form of a sealed enclosure containing a body of gas having predetermined characteristics, and including a cathode 20, a radio-active source adjacent thereto, and an ion collector anode 21.
  • the cathode 20 is connected to the anode 9 of the primary or detecting ionizing chamber 1 to provided a common junction 19 constituting the voltage take-off or output terminal of the detector system.
  • a source 18 of D.-C. voltage is shown as providing the necessary power for polarizing the respective electrodes of the system.
  • the cathode 8 and screening electrode or grid 11 of the primary chamber are both connected to the negative terminal of source 18 by way of a resistor.
  • the anode 21 of the reference chamber is connected to the positive terminal by way of a resistor.
  • Thermistor devices or resistors having a high negative thermal coeificient of resistance are shown at 22 and 23 as connected between the primary chamber cathode 8 and the positive pole of the source 18 for compensation of effects of temperature variations on the circuit charac teristics.
  • the adjustments are so made that the reference ionization chamber 2 is operated substantially at saturation.
  • the voltage variations at the junction 19 are accurately representative of the variations in composition of the gas flowing through the primary chamber 1, i.e. are representative of the departure of the condition of the gas in chamber 1, from the reference condition of the gas present in chamber 2.
  • the use of the reference chamber 2 in conjunction with the primary detector chamber 1 provides a comparison effect which substantially eliminates the influence of disturbing factors such as variations in temperature and pressure, since such disturbing factors can be made to affect the gases in both chambers equally.
  • the voltage appearing at junction 19 is applied to an output or control circuit which is so designed as to prevent any back-action from said circuit upon the voltage at junction 19 liable to disturb the proper operation of the detector system.
  • a multi-electrode tube 26 including a cathode 27, a first grid 28 and a second or control grid 29.
  • the tube 26 may be a conventional multi-electrode tube including further electrodes, such as a plate, in addition to those mentioned, in which case such additional electrode or electrodes would not be used.
  • the cathode 27 is connected to the negative terminal of an adjustable D.-C. source 30, which negative terminal is desirably grounded and simultaneously provides the reference voltage for the shielding member 4 of the primary ionizing chamber 1.
  • a connection from said negative terminal of source 30 to the adjustable tap of a potentiometer resistance connected across the source 18, as shown, permits of adjusting the various afore-mentioned polarizing potentials relatively to said reference voltage.
  • the first or output grid 28 of tube 26 is connected to one end of the winding of a milliammeter instrument 31 the other end of which is connected with the positive terminal of source 30.
  • the second grid 29, which constitutes a control electrode of the tube 26, is connected to the junction 19.
  • the bias potentials for tube 26 are so adjusted that the control grid 29 is at all times biassed to a voltage negative relative to cathode 27, so that the tube 26 is at all times cut off, that is to say, there is no electron current in the tube 26 to the control grid 29 but only to the output grid 28.
  • the variations of the negative voltage on control grid 29 as derived from the junction 19 generate within tube 26 a varying inhibitor field so that the current applied from grid 28 to the milliammeter winding constitutes an amplified replica of the voltage variations at point 19.
  • the source 30 is indicated as being adjustable, e.g. by means of a voltage divider or the like schematically indicated by the arrow across the source, and the voltage is so adjusted that in the normal or reference condition of the gas being tested the pointer of the milliammeter 31 indicates the central zero of the scale.
  • Contacts 32 and 32 are provided at the opposite ends of the scale with which the pointer is adapted to make contact When it is displaced beyond either end of a pre set range.
  • the system is used as a fire detector, in which case the gas flowing through the ionization chamber 1 is atmospheric air from the space being supervised, then should the air-flow be contaminated with smoke or combustion gases, the ions emitted by the source 12 are retarded and tend to recombine more rapidly so that the internal resistance of the chamber -1 increases.
  • the potential at point 19 rises and the current through milliammeter 31 also rises.
  • a connection is established from a positive voltage source with which said pointer is connected to the base 34 of a power-transistor 35, thereby arresting the flow of current from the emitter 33 to the base, and hence also arresting the current in the collector electrode 36 of said transistor.
  • a relay winding 37 connected in the collector circuit is thereby deenergized and the relay contacts 3839 move to their normally closed position; this completes an energizing circuit for an alarm siren 40 and a warning signal lamp 41.
  • a similar circuit including a power-transistor, relay and alarm devices is connected to a contact 32 provided at the opposite end of the milliammeter scale, symmetrically with the circuit just described; the components thereof are designated by the same references primed.
  • the milliammeter pointer would be displaced to its rightward or leftward end position thereby operating the warning signal means and attracting attention to the defect.
  • a push-button switch 42 is used depression of which connects the pointer of the milliammeter to a negative polarity without requiring operation of a switch to cut off the energizing circuit for said pointer.
  • FIG. 2 illustrates a modified construction of the primary ionizing chamber, which can be substituted for the chamber 1 in FIG. 1.
  • the modified chamber shown in FIG. 2 is of symmetrical construction and includes, to either side of the ion collector anode 9 two pairs of radiation sources 24a, 24b on one side and 25a, 25b on the other side each emitting alpha-particles in opposite directions. Such a chamber can be exposed to gas flow in either direction indiscriminately.
  • any of the ions formed between source 2412 and the anode 9 and entrained without being captured by the anode are compensated for, at least in part, by those ions that are formed from the source 24a and carried towards the anode 9. Since the rate of recombination of the ions depends on the velocity of gas flow, it will be seen that should the flow velocity increase thereby increasing the amount of ions produced by source 24b that are lost by entrainment with the gas, at the same time the number of ions produced by the particles emitted by source 240 and collected by the anode 9 also increases so that satisfactory compensation obtains.
  • Such an ion1z ing chamber is especially well-suited for use in circumstances where the gas flow is apt to occur at variable velocities and is even liable to reverse in direction, as is the case in large drafty halls such as warehouses, hangars and the like.
  • the detecting and supervising system of the invention s susceptible of receiving a wide number of different applications especially owing to the number of different adjustments of which it is capable. It can readily be constructed in the form of a compact portable unit. Alternatively it may be installed at a central supervising station and a rotary distributor may be provided whereby the atmosphere in a plurality of different locations may be cyclically supervised by means of a common detector unit. In such case, a common electrically operated fan may be provided for delivering the gas to be controlled from a plurality of conduits into the ionizing chamber.
  • a plurality of similar detecting units may be provided in the respective spaces to be supervised, all connected electrically to a central station including the control, indicating and alarm circuitry.
  • the system provides a means of supervising the variations in composition of a gaseous mixture, and such variations may be recorded, e.g. as concentrations of a predetermined constituent in cases where only a single constituent of the mixture is variable. This may be the case in installations for supervising the combustion gases from a furnace or the like, exhaust gases of combustion engines or from jet engines, e.g. during bench tests, and similar applications.
  • Another possible application of the system is for the supervision and control of the degree of atmospheric pollution in underground highways and highway tunnels, buildings containing various kinds of pressure gas equipment, mines (including firedamp control), and the like.
  • the system can also serve for controlling a reducing gas atmosphere against the possible ingress of atmospheric air (or other gases) in various apparatus such as treating furnaces, A.-C. generators operated in an atmosphere of hydrogen, and so on.
  • a tubular outer member of electrically conductive material a tubular inner member of insulating material defining an ionization chamber
  • means for delivering a stream of gaseous fluid through said inner member a cathode electrode, a radioactive source adjacent the cathode, an ion-collecting anode electrode spaced from the cathode and a screen electrode positioned downstream from said ion-collecting anode spaced from the anode, means supporting said electrodes from said inner member Within said chamber, means applying a fixed reference potential to said outer member, electric supply means applying operating potentials to said electrodes, the potential applied to the screen electrode being negative relative to said anode, and circuit means connected to said anode and responsive to the variations in ions collected thereby from said stream gheireby to respond to the composition of said gaseous 2.
  • a tubular outer member of conductive material In apparatus continuously responsive to the composition of a gaseous fluid, a tubular outer member of conductive material, a tubular inner member of insulatmg material, spaced cathode, anode and screen electrodes supported in and from said inner member, means applymg a fixed reference potential to said outer member, electric supply means applying operating potentials to said electrodes to maintain the screen electrode negative relative to the anode, means for delivering a stream of said fluid through the inner member to be ionized by said source, a sealed reference chamber containing a body a of reference gaseous fluid therein, a cathode and anode and a radioactive source within said sealed chamber, means applying an operative potential to said last mentioned anode, a junction connected both to said first mentioned anode and to said second mentioned cathode, and circuit means connected to said junction and responsive to the potential thereat as determined by the variations in composition of said stream of gaseous fluid relative to the composition of said gaseous fluid in the reference
  • an electric heater element adjacent said source for preventing moisture condensation on an emissive surface of said source.
  • circuit means comprises a multielectrode tube having a.
  • cathode a first grid and a second grid
  • a multielectrode tube in said circuit means including a cathode, a first grid and a second grid, means biassing the first grid posieluding a winding connected to said first grid, a displaceable member operable by current in said winding and limit stop means operable by said pointer on predetermined displacement thereof from a null position, a transistor having a base, a collector and an emitter, means applying an operative bias to said base; relay means connected to said collector, a load operated by said relay means, and means connecting said limit contact means with said base bias means for modifying said bias to operate said load.
  • means for adjusting the range of said predetermined displacement of said pointer from null position to modify said bias and operate said load including means whereby said pointer is displaced beyond said range in case of defective operation of said apparatus.
  • a tubular outer member continuously responsive to variations in composition of a gaseous fluid, a tubular outer member 'of electrically conductive material, a tubular inner memher of insulating material defining an ionization chamber open at both ends for free circulation therethrough, an ion-collecting anode electrode within said tubular inner member, two pairs of radioactive sources one pair on each side or said anode and arranged to emit ionizing radiation in opposite directions, means for comparing the rate of ion collection by said anode, said means being electrically connected to said anode and to said outer member, and circuit means connected to said anode and responsive to the variations in ions collected thereby from the gas inside of said ionization chamber whereby to respond to the composition of the gas.

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US714341A 1957-10-24 1958-02-10 Apparatus responsive to the composition of a gaseous medium Expired - Lifetime US3028490A (en)

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FR1089193X 1957-10-24

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US (1) US3028490A (fr)
CH (1) CH349105A (fr)
DE (1) DE1089193B (fr)
FR (1) FR1185495A (fr)
GB (1) GB828121A (fr)
NL (1) NL224264A (fr)

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3244914A (en) * 1962-03-20 1966-04-05 Union Carbide Corp Thermoelectric conversion process and apparatus
US3304545A (en) * 1962-10-01 1967-02-14 Owen K Bell Combustion products detector
US3322977A (en) * 1962-03-20 1967-05-30 Union Carbide Corp Thermionic conversion process and apparatus
US3361908A (en) * 1964-01-03 1968-01-02 Barber Colman Co Method and apparatus for electron attachment detection
US3423585A (en) * 1964-08-24 1969-01-21 Central Investment Corp Of Den System for detecting suspended colloidal solids in a gas utilizing an ionization chamber and a step-down amplifier
US3445757A (en) * 1965-10-14 1969-05-20 Mc Donnell Douglas Corp Capillary ionization gas detector and analyzer using timed interval current fluctuations
US3765842A (en) * 1970-07-31 1973-10-16 Cerberus Ag Fire alarm signalling system
US4099178A (en) * 1977-04-07 1978-07-04 Emdeko International, Inc. Test means for light responsive smoke detector
EP0004124A1 (fr) * 1978-03-15 1979-09-19 Pye (Electronic Products) Limited Procédé et appareil pour détecter des traces de vapeur
US4177378A (en) * 1978-04-24 1979-12-04 Randam Electronics, Inc. Long-lived reference cell simulating the α scintillation of radon-222
US4308458A (en) * 1978-09-11 1981-12-29 Commissariat A L'energie Atomique Fire detectors utilizing an ionization chamber not subject to condensation of water vapor during variations of temperature
US4338568A (en) * 1980-03-28 1982-07-06 Nasa Method and device for detection of a substance
US4345154A (en) * 1979-01-12 1982-08-17 The United States Of America As Represented By The Secretary Of The Army Bias-compensated, ionization sensor for gaseous media and method for attaining proper bias for same
US4704536A (en) * 1983-12-23 1987-11-03 Hochiki Corporation Gas sensor and gas detecting method
US4770027A (en) * 1986-03-24 1988-09-13 Katuo Ehara Method of measuring concentrations of odors and a device therefor
US5058418A (en) * 1988-05-18 1991-10-22 Newbow Engineering Industries Limited Reversible adaptor and gas analyzer for tires
FR2746184A1 (fr) * 1996-03-15 1997-09-19 Lewiner Jacques Detecteur de fumee a ionisation d'air par voie electrique
EP0838795A1 (fr) * 1996-10-24 1998-04-29 Pittway Corporation Détecteur de condition ambiante
US20080117065A1 (en) * 2006-11-20 2008-05-22 Honeywell International, Inc. Sensing Chamber with Enhanced Ambient Atmospheric Flow
EP2090325A2 (fr) * 2006-11-07 2009-08-19 Andrey Andreevich Churkin Procédé de désinfection de l'air à l'aide d'ions négatifs d'oxygène et dispositif permettant sa mise en oeuvre

Families Citing this family (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH380594A (de) * 1960-11-02 1964-07-31 Securiton Ag Ionisations-Brandmeldeanlage
DE1198712B (de) * 1961-12-30 1965-08-12 Danske Securitas As Elektrische Alarmanlage
DE1194293B (de) * 1962-02-16 1965-06-03 Telefonbau UEberwachungsgeraet mit Ionisationskammer
DE1279513B (de) * 1963-10-16 1968-10-03 Pour Applic Electroniques Ets Ionisationsmelder, dessen Ionisationskammer fuer die Atmosphaere zugaenglich ist
IL22673A (en) * 1964-12-27 1968-06-20 Jaffe A Sensitive smoke and fire detector
FR1480257A (fr) * 1966-03-28 1967-05-12 Commissariat Energie Atomique Chambre d'ionisation à circulation
NO129270B (fr) * 1970-05-16 1974-03-18 Preussag Ag Feuerschutz
JPS5737916B2 (fr) * 1972-07-14 1982-08-12
FR2208150B1 (fr) * 1972-11-29 1977-07-22 Hochiki Co
CH554033A (de) * 1973-04-03 1974-09-13 Cerberus Ag Iomisations-feuermelde-einrichtung.
US4021671A (en) * 1975-07-07 1977-05-03 Gulf & Western Manufacturing Company (Systems) Ionization detector
BE831296A (fr) * 1975-07-11 1975-11-03 Detecteur ionique
US4013913A (en) * 1976-01-19 1977-03-22 Hnu Systems Inc. Ion detection electrode arrangement
DE2724510C2 (de) * 1977-05-31 1985-04-11 Brunswick Corp., Skokie, Ill. Frühwarnfeuermelder
FR2430612A1 (fr) * 1978-07-05 1980-02-01 Ugon Pierre Chambre d'ionisation reglable
DE2846310C3 (de) * 1978-10-24 1982-01-28 Preussag Ag Feuerschutz, 2060 Bad Oldesloe Brandmeldeeinrichtung für einen Raum großer Höhe und vorzugsweise großen Volumens, insbesondere eine La ger- oder Fabrikhalle
FR2594953B1 (fr) * 1986-02-25 1989-05-05 Lewiner Jacques Detecteur de fumee a chambre d'ionisation

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB389722A (en) * 1931-08-10 1933-03-23 Bbc Brown Boveri & Cie Improvements in and relating to the transmission of electrical energy between alternating current networks of different frequencies
US2594777A (en) * 1950-07-14 1952-04-29 Ionics Ion controller
US2641710A (en) * 1951-03-02 1953-06-09 Shell Dev Radiological gas analysis
US2702898A (en) * 1953-10-06 1955-02-22 Electro Watt Electrical And In Gas-responsive control apparatus
US2761976A (en) * 1951-04-17 1956-09-04 Illinois Testing Laboratories Methods and apparatus for measuring quantitatively the amount of gas in a mixture
US2817768A (en) * 1954-09-16 1957-12-24 Tung Sol Electric Inc Radiation alarm
US2883555A (en) * 1956-05-28 1959-04-21 Curtiss Wright Corp Thickness measuring apparatus with compensation for atmospheric conditions

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH199517A (de) * 1936-12-02 1938-08-31 C Jaeger Walter Verfahren und Vorrichtung zur Anzeige des Zustandes eines Gases.
GB657548A (en) * 1947-12-15 1951-09-19 Electronic Instr Ltd Improvements in or relating to devices for testing gases

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB389722A (en) * 1931-08-10 1933-03-23 Bbc Brown Boveri & Cie Improvements in and relating to the transmission of electrical energy between alternating current networks of different frequencies
US2594777A (en) * 1950-07-14 1952-04-29 Ionics Ion controller
US2641710A (en) * 1951-03-02 1953-06-09 Shell Dev Radiological gas analysis
US2761976A (en) * 1951-04-17 1956-09-04 Illinois Testing Laboratories Methods and apparatus for measuring quantitatively the amount of gas in a mixture
US2702898A (en) * 1953-10-06 1955-02-22 Electro Watt Electrical And In Gas-responsive control apparatus
US2817768A (en) * 1954-09-16 1957-12-24 Tung Sol Electric Inc Radiation alarm
US2883555A (en) * 1956-05-28 1959-04-21 Curtiss Wright Corp Thickness measuring apparatus with compensation for atmospheric conditions

Cited By (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3244914A (en) * 1962-03-20 1966-04-05 Union Carbide Corp Thermoelectric conversion process and apparatus
US3322977A (en) * 1962-03-20 1967-05-30 Union Carbide Corp Thermionic conversion process and apparatus
US3304545A (en) * 1962-10-01 1967-02-14 Owen K Bell Combustion products detector
US3361908A (en) * 1964-01-03 1968-01-02 Barber Colman Co Method and apparatus for electron attachment detection
US3423585A (en) * 1964-08-24 1969-01-21 Central Investment Corp Of Den System for detecting suspended colloidal solids in a gas utilizing an ionization chamber and a step-down amplifier
US3445757A (en) * 1965-10-14 1969-05-20 Mc Donnell Douglas Corp Capillary ionization gas detector and analyzer using timed interval current fluctuations
US3765842A (en) * 1970-07-31 1973-10-16 Cerberus Ag Fire alarm signalling system
US4099178A (en) * 1977-04-07 1978-07-04 Emdeko International, Inc. Test means for light responsive smoke detector
EP0004124A1 (fr) * 1978-03-15 1979-09-19 Pye (Electronic Products) Limited Procédé et appareil pour détecter des traces de vapeur
US4177378A (en) * 1978-04-24 1979-12-04 Randam Electronics, Inc. Long-lived reference cell simulating the α scintillation of radon-222
US4308458A (en) * 1978-09-11 1981-12-29 Commissariat A L'energie Atomique Fire detectors utilizing an ionization chamber not subject to condensation of water vapor during variations of temperature
US4345154A (en) * 1979-01-12 1982-08-17 The United States Of America As Represented By The Secretary Of The Army Bias-compensated, ionization sensor for gaseous media and method for attaining proper bias for same
US4338568A (en) * 1980-03-28 1982-07-06 Nasa Method and device for detection of a substance
US4704536A (en) * 1983-12-23 1987-11-03 Hochiki Corporation Gas sensor and gas detecting method
US4770027A (en) * 1986-03-24 1988-09-13 Katuo Ehara Method of measuring concentrations of odors and a device therefor
US5058418A (en) * 1988-05-18 1991-10-22 Newbow Engineering Industries Limited Reversible adaptor and gas analyzer for tires
FR2746184A1 (fr) * 1996-03-15 1997-09-19 Lewiner Jacques Detecteur de fumee a ionisation d'air par voie electrique
WO1997035287A1 (fr) * 1996-03-15 1997-09-25 Jacques Lewiner Detecteur de fumee a ionisation d'air par voie electrique
EP0838795A1 (fr) * 1996-10-24 1998-04-29 Pittway Corporation Détecteur de condition ambiante
US5926098A (en) * 1996-10-24 1999-07-20 Pittway Corporation Aspirated detector
US6166648A (en) * 1996-10-24 2000-12-26 Pittway Corporation Aspirated detector
AU737951B2 (en) * 1996-10-24 2001-09-06 Pittway Corporation Aspirated detector
EP2090325A2 (fr) * 2006-11-07 2009-08-19 Andrey Andreevich Churkin Procédé de désinfection de l'air à l'aide d'ions négatifs d'oxygène et dispositif permettant sa mise en oeuvre
EP2090325A4 (fr) * 2006-11-07 2010-01-20 Andrey Andreevich Churkin Procédé de désinfection de l'air à l'aide d'ions négatifs d'oxygène et dispositif permettant sa mise en oeuvre
US20080117065A1 (en) * 2006-11-20 2008-05-22 Honeywell International, Inc. Sensing Chamber with Enhanced Ambient Atmospheric Flow
US7656302B2 (en) 2006-11-20 2010-02-02 Honeywell International Inc. Sensing chamber with enhanced ambient atmospheric flow

Also Published As

Publication number Publication date
FR1185495A (fr) 1959-07-31
CH349105A (fr) 1960-09-30
DE1089193B (de) 1960-09-15
GB828121A (en) 1960-02-17
NL224264A (fr)

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