Abstract: An ionization smoke detector device including means for insuring that adjustment can be made in the triggering potential for the alarm device so that should circumstances change, an operator can make a simple adjustment to take into account the changed circumstances. This means comprises a programmable Zener diode which is connected to a voltage dividing resistance network at the output of a field effect transistor, the other end of the Zener diode being connected to the input of a silicon controlled rectifier device which functions to trigger the alarm.Another primary feature of the present invention is the provision of a means for testing the operation of the system in such a way that all of the elements of the system will be tested rather than merely some of them.

Abstract: A smoke detector containing at least one smoke measuring chamber which possesses a mounting or socket plate having an upper surface intended to be mounted at the ceiling of a room or other appropriate area to be monitored and a housing enclosing the smoke measuring chamber and suspendingly secured at the socket plate. The housing possesses openings for the entry of the ambient air into the smoke measuring chamber. The smoke detector comprises a manually adjustable device by means of which it is possible to change the air entry openings in a manner such that the smoke detector can be accommodated to different environmental or ambient conditions, especially those containing different quantities of dust and other contaminants.

Abstract: This invention is a smoke detector for giving a warning that a fire is imminent. The detector has an ionization chamber with a central electrode which is covered by insulation except at a restricted area closely spaced from a measuring electrode, a second electrode being constituted by a perforated wall of the ionization chamber. The detector is very sensitive to the presence of smoke, because of the concentration of the electric field in the area between the measuring electrode and the exposed part of the first electrode.

Abstract: Condensation of water vapor on a radiation source in a fire detector is prevented by heating the source using the Joule effect. The heat is provided by a resistor embedded in the ceramic support for the source.

Abstract: In an electronic smoke sensing and alarm device, a dual ionization chamber arrangement comprises a single source of radioactive material and first and second chambers separated by a common electrically conductive electrode. A portion of the radioactive material ionizes the air in the first chamber and another portion of the radioactive material ionizes the air in the second chamber. This arrangement provides an accurate control on the current flow through each chamber.

Abstract: Method and apparatus for detecting the presence of very small concentrations of certain vapors and gases in air or other gaseous backgrounds. A gas sample is ionized by a source of ionizing radiation. The ionized gas is then directed through a first drift region where the ions are subjected to a drift potential. Electrical biased grid means are provided to allow only heavier ions of lower mobility to pass through the first drift region into a second drift region, where electrical shutter means are provided to allow discrete packets of ions to pass and to drift at speeds depending upon their mobilities and be detected. In an alternate embodiment, the first draft region is positioned downstream from the second drift region.

Abstract: An ionization-type particle detector having an insulating base which mounts an inner electrode provided with a source of ionizing radiation which directs a generally conical beam perpendicularly away from the base; an intermediate cylindrical electrode symmetrically disposed around the inner electrode which has an open upper end through which the radiation beam exists from a compensation zone defined by the inner and intermediate electrodes; and an outer cup-shaped electrode symmetrically disposed about the intermediate electrode and which defines therewith a sensing zone into which radiation enters from the top opening in the intermediate electrode. The sensing zone is divided by the envelope of the radiation beam into an upper bipolar region and a lower unipolar region.

Abstract: An ionization chamber for a smoke detector is disclosed wherein entry of airborne combustion products to the chamber is enhanced by an improved aperture and inlet surface arrangement which is formed in an electrode housing member for the chamber.

Abstract: Method and apparatus for the detection of electronegative chemical species in gas flows, such as exist from gas chromatographs, by sampling the detector volume via an aperture connecting to a lower pressure region containing apparatus to collect and measure the negative ion current. Because of the free diffusion of electrons in the region of the aperture, as opposed to ambipolar diffusion in a conventional electron capture detector volume, the electrons are largely removed from the negatively charged components in the gas stream there. Similarly, positive ion current may be measured, thus extending the analytical capability of the invention to classes of chemical species normally not yielding a response in electron capture detectors.

Abstract: Method and apparatus for detecting the presence of very small concentrations of certain vapors and gases in air or other gaseous backgrounds. A gas sample is ionized by a source of ionizing radiation. The sample of ionized gas is then directed through a recombination region where ions are selectively recombined. The ionized gas is further directed through a drift region where the ions are subjected to a drift potential and separated into different groups, depending upon their mobilities. In an alternate embodiment, the ionized gas is first directed through a drift region, followed by a recombination region.

Abstract: An ionization detector, such as an electron capture detector for use in pesticide residue analysis, utilizes a scandium tritide beta particle source. The scandium tritide forms a surface portion of a metallic foil. If the foil initially exhibits an unacceptably high tritium emanation rate at desired high operating temperatures, e.g., at temperatures above 250.degree. C, the foil can be treated so as to exhibit an acceptable tritium emanation rate at such temperatures. The treatment comprises heating the foil at a predetermined treatment temperature, e.g., at a selected temperature in the 300.degree. to 400.degree. C range, until the tritium emanation rate for the foil at the selected treatment temperature reaches a value which correlates with an acceptable tritium emanation rate for the foil at a particular desired operating temperature.

Abstract: In a hydrogen cooled dynamoelectric machine, an ion chamber detector monitors thermally produced particulates. Specificity and sensitivity of the ion chamber detector are improved by applying an electrical potential of a limited predetermined range to the electrodes of the detector and operation of the detector occurs within a well defined subsaturation range.

Abstract: An improved detector apparatus is provided in combination with a gas cooled dynamoelectric machine for detecting the presence of pyrolysate products in the machine gas coolant indictive of localized overheating of certain dynamoelectric machine parts. The detector apparatus is of the type which analyzes an ionized gas sample by measuring the current flow in the gas sample. A decrease in current flow is indicative of the presence of submicron particulates. The present invention resides in heating the gaseous sample to eliminate more volatile submicron particulates so that the output signal from the detector apparatus is indicative only of the presence of pyrolysate products resulting from the localized overheating of certain dynamoelectric machine parts.

Abstract: An instrument to detect submicron particles by charge-transfer attachment. The instrument is made up of a charging chamber with two concentric cylindrical electrodes, a remote third collector electrode, and a pump to force ambient air through the charging chamber and into the collection electrode. The innermost electrode of the charging chamber is supplied with a radioactive material having a gold foil covering. This material can create a small bipolar region symmetrical to the inner electrode where primary ionization takes place. Positive ions created in this region move to the larger outside unipolar region to attach themselves to submicron particles. These charged particles are then forced from the charged chamber at which time they may either impinge on the collection electrode to create a measurable axial current or the particles may enter a size discrimination chamber.

Abstract: This invention relates to a detector for detecting the state of electrically non-conductive or substantially electrically non-conductive fluid, such as its flowing velocity, direction, composition or pressure, comprising a transducer to generate an electric signal responsive to said state of said fluid, said transducer having at least one ionizing area exposed to said fluid and said electric signal appearing as variation in conductance across said ionizing area, an amplifier to amplify said electric signal from said transducer, having a high input impedance and a low output impedance, and means to shield said transducer and said amplifier.

Abstract: Ionization detector capable of operation at elevated temperatures and utilizing iron-55 as a radioactive source within the ionization chamber.

Abstract: The detector comprises a chamber having at least one radiation source disposed therein. The chamber includes spaced collector plates which form a part of a detection circuit for sensing changes in the ionization current in the chamber. The radiation source in one embodiment is in the form of a wound wire or ribbon suitably supported in the chamber and preferably a source of beta particles. The chamber may also include an adjustable electrode and the source may function as an adjustable current source by forming the wire or ribbon in an eliptical shape and rotating the structure. In another embodiment the source has a random shape and is homogeneously disposed in the chamber.

Abstract: An ionization analyzing alarm system of extreme accuracy independent of aspheric turbulences caused by fire and of minute dimensions, ease and safety of manufacture, assembly and repairs and devoid of forced air devices, is provided, having an air baffle zone, a first ionization chamber with advantageously located electrodes, radioactive source and circuitry and optionally a second ionization chamber with radioactive source and an additional electrode, the central of the three electrodes serving both chambers and with sensitivity controls.

Abstract: An ionization analyzing alarm system of extreme accuracy independent of atmospheric turbulences caused by fire and of minute dimensions, ease and safety of manufacture, assembly and repairs and devoid of forced air devices, is provided, having an air baffle zone, a first ionization chamber with advantageously located electrodes, radioactive source and circuitry and optionally a second ionization chamber with radioactive source and an additional electrode, the central of the three electrodes serving both chambers and with sensitivity controls.