Abstract: The capacitive effect of a coaxial cable coupled to an ionization probe is reduced by an operational amplifier which applies a constant bias voltage to the coaxial cable.

Abstract: A halogen gas detector employing the negative corona principal is equipped with a corona discharge sensing tip utilizing the "electrical wind" phenomenon of field corona discharge to create a continuous flow of the gas sample being sensed through the corona, thereby ensuring that virtually every molecule of halogen gas impurity comes into contact with the corona discharge for dependable, uniform, and substantially instantaneous gas sensing operation.

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: A short-circuited loop of conductor 10, 32, 44, 54 comprises an electromagnetic short-circuit hoop probe which is electrically insulated from a gas stream passing therethrough either by spatial isolation (FIG. 2) or by a coating of electrical insulation (FIGS. 3-5), whereby to reduce noise and DC current levels which could otherwise pollute signals of interest therein. A large hoop version of the non-contact probe permits electrostatic diagnostics of gas streams downstream of flame (FIG. 2).

Abstract: An improved apparatus for measuring the grain-size composition of powders in which a device for transforming a powder into a gaseous flow of individual particles, a charging chamber in which each particle acquires a charge which is proportional to its surface area, a precipitating capacitor in which the flow of charged particles is separated into various fractions in accordance with the charge on the particles, an electrometric device for measuring the total charge of individual fractions are provided, the electrometric device having inductive sensors of charged particles, the number of inductive sensors being equal to the number of fractions, and an amplifier to which are connected all inductive sensors of charged particles. The improvement comprises a plurality of switching devices, one switching device being provided for each sensor.

Abstract: The invention provides apparatus and method for measuring the concentration of large particles in a gas which may also contain small particles. The apparatus comprises a triboelectric charging means which effects triboelectric charging of the large particles in the gas, and charge measuring means for measuring charges on the particles in the gas after it has passed the triboelectric charging means. The triboelectric charging means can be a curved section of an air intake duct or the compressor of a turbocharger. The apparatus enables the operation of an engine or other air consuming device to be interrupted when the concentration of large particles in the incoming air is sufficient to damage the engine, but avoids unnecessary shutdowns due to the presence of small particles, e.g. smoke particles, which are too small to damage the engine or other device.

Abstract: A device for detecting the isoelectric end point in an isoelectric focusing system by electronically integrating, over successive time intervals, a characteristic of the electrical input to said zone as it varies with the increasing resistance of the zone. Most conveniently, the measured characteristic is the current through the zone which, under constant impressed voltage or power, asymptotically approaches a minimum value as the end point is reached.The measured characteristic is continually converted to a sequence of pulses indicative of the value of the characteristic. The end point is indicated when the difference between counts of these pulses over successive time intervals reaches a preselected value. At the end point, provision is made for replacement of the focusing voltage with a lower voltage to keep the ampholytes focused. A signal can be activated at the end point.

Abstract: A combustible gas detection system in which remotely located combustible gas sensors of the analog type are monitored by a central controller. The sensor analog data is converted to digital data and transmitted to the controller. The controller tests the integrity and validity of data received from the sensor, identifies the nature of any faults therein and vocally signals the cause of such faults. The controller computes the concentration of combustible gas at the sensor and automatically determines sensor calibration constants from received sensor data.

Abstract: A method and apparatus are provided for indicating an operating characteristic of a periodically combusting internal combustion engine, such as a diesel engine, having exhaust gas issuing from one or more combustion chambers in a periodic manner through a duct. The particulate in the exhaust gas stream are electrically charged and of the same polarity, and are grouped in packets associated with the periodic combustion in the respective chambers. An electrically conductive, passive electrode, preferably annular in shape, is disposed such that most or all of the exhaust gas flows therethrough so as to electrostatically sense, principally by induced image charge, the passage of the respective packets of charged particles. The electrode is electrically isolated from the duct.

Abstract: A tri-electrode probe consisting of a central electrode and a pair of measuring electrodes on the opposite sides of the central electrode disposed so as to symmetrically cover an immaginary surface having a plane of symmetry, is connected to a measuring system including minute current ammeters and a variable D.C. voltage source, the tri-electrode probe is positioned at a measuring point within an electric field where both positive and negative ions coexist as oriented in such direction that the plane of symmetry is directed in perpendicular to the direction of the electric field with one of the measuring electrodes opposed to a negative ion source and the other measuring electrode opposed to a positive ion source, a current flowing through the minute current ammeter connected to the central electrode is made substantially zero by varying the voltage of the variable D.C.

Abstract: A method and apparatus are disclosed for measuring interfacial electrokinetic phenomena such as electrophoresis by applying stationary electric field to a sample, wherein the voltage between two points in the sample other than the electrodes for an electric current application is detected and the electric current is supplied to the sample to maintain the detected voltage constant, and the sample is preheated while the particles being substantially kept in a stationary state by applying an alternating voltage prior to the application of the stationary voltage, to thereby obtain the mobility of the charged particle in the sample at high accuracy.

Abstract: The flame ionization detector includes basically a nozzle for a measuring gas fuel gas mixture and is coaxially disposed to a target electrode. Materials and dimensions for these components are critical and include a platinum metal nozzle tip, a noble metal surface target electrode, a limited range for the nozzle duct diameter, a limited range for the relative position between the nozzle tip and the lower end of the target electrode, and angle ranges for conical nozzle contour surfaces.

Abstract: A gas discharge tube is provided for use in a detector of the type capable of identifying ionizable species in a carrier gas. The tube contains an inert gas at reduced pressure and the gas is excited by an external circuit including a coil about the tube. The circuit generates a radio frequency which excites the gas and emits ultraviolet radiation. This radiation passes through a transversely located window at the end of the tube for ionizing the species in a chamber. Electrodes are also described for use in association with the chamber to sense ionization. These electrodes form part of a sensing circuit.

Abstract: A method of measuring the oxygen partial pressure in an atmosphere in which a temperature T.sub.c at which the free energy of formation of an oxide of a metal such as palladium in contact with the atmosphere is determined to provide a measure of the partial pressure of oxygen. Apparatus for use in the method comprises an electrolytic cell including an electrode of the said metal and an electrolyte such as yttria stabilized zirconia having ionic oxygen mobility.

Abstract: The present invention is directed to an ionization cell for detecting the presence of very minute concentrations of certain chemical agents. The effective sensitivity of conventional chemical agent detectors is restricted in the presence of certain interferants such as jet fuel, gasoline, smoke, turpentine and the like. Herein a "chemical bias," that is a background concentration of a simulant is provided at the inlet of an ionization detector, which chemical bias is effective by charge exchange to prevent the interferants from dominating the signal.

Abstract: Electrochemical measuring device for determining the oxygen content in gases with approximately constant pressure, especially in combustion exhaust gases, with an oxygen ion-conducting solid electrolyte having two electrodes connected to a voltage source, and measuring changes in current. In combination with the electrical measuring device, a constriction is disposed in the path of the constant pressure gas stream with the constriction having a passageway of cross sectional area to pass the gas stream at the velocity of sound under the condition of critical pressure ratio dependent on a ratio of the pressure at the outflow side of the inflow side of the constriction which brings about sound velocity of the gas stream.

Abstract: A device for measuring the amount of oxygen in combustion gas including succesively, a channel bordered by two plates between which exists a magnetic field, a central electrode divided in two, longitudinally, a gas discharge path, and finally a mechanism for measuring the current or ionization potential in each of the paths. This device is, accordingly, applicable to the automobile industry and automation and regulation of the operation of boilers of all kinds.

Abstract: An ionization detector unit innovatively adapted to provide mobility to the nit and to render it especially suitable for convenient "field-use" in point-source sampling and monitoring of the compositional characteristics of a gaseous medium such as, for example, the ambient atmosphere, and in emitting a discernible electrical signal which in response to a perceptible change in the compositional characteristics in the medium being monitored by the detector will be altered sufficiently to activate, or trigger, a suitable alarm or warning mechanism.

Abstract: A process for measuring the concentration of oxygen in a gaseous mixture, and particularly for determining the percentage of oxygen in the exhaust gases of an internal or external combustion engine, and ionization probes for the carrying out of this process.

Abstract: Method and apparatus for monitoring characteristics of a high energy neutral beam. A neutral beam is generated by passing accelerated ions through a walled cell containing a low energy neutral gas, such that charge exchange neutralizes the high energy ion beam. The neutral beam is monitored by detecting the current flowing through the cell wall produced by low energy ions which drift to the wall after the charge exchange. By segmenting the wall into radial and longitudinal segments various beam conditions are further identified.

Abstract: This device for measuring a physical operating characteristic of an ozonizer such as, for example, the ozonization power, the production of ozone or the concentration of ozone in the air, comprises a medium or high-frequency sensor placed in the ozonization zone of the ozonizer and an electronic processing circuit which delivers a signal which is an image of the energy received by the sensor. The sensor detects the medium or high-frequency energy produced in the ozonizer and produces a signal which is an image of one of the aforementioned physical characteristics owing to the fact that the curves of these characteristics are colinear with those of the medium and high-frequency energy components.

Abstract: A gas detecting means of this invention is provided with a discharge section which radiates light by electric discharge, a detecting section which collects an ion current of a sample gas ionized by the light, and an optical path which connects the discharge and the detecting sections. The discharge is formed by a pointed cathode and an anode having a penetration hole. The tip of the pointed cathode is directed to the optical path. The diameter of the penetration hole of the anode is smaller than that of the optical path. The anode is disposed in such a manner that any peripheral part of an inlet of the penetration hole is at an equal distance from the tip of the cathode. Both the discharge section and the detecting section are shielded electrically by an outer shell of metal.

Abstract: A probe operable in conjunction with an electrometer having a high input impedance to provide an instrument for measuring air ion flux density. The probe structure is such that its presence in the atmosphere in which a measurement is being carried out will not give rise to perturbations in the localized electric field and therefore has no perceptible effect on the accuracy of measurement. The probe is constituted by a metal target to which the ions give up their charge, the target being supported at the end of a barrel of dielectric material by a conductor attached thereto and extending axially through the barrel to a contact at the rear of the barrel which is connected to the line of a shielded coaxial cable which couples the target to the input terminal of a grounded electrometer, the shield of the cable also being grounded. The surface of the barrel is coated with a layer of semi-conductive material that makes contact at the lower end of the barrel with the grounded cable shield.

Abstract: An apparatus and method for momentary sampling of an atmosphere to determ electrostatic charge density is disclosed. A nonconductive elongated sampling tube is inserted into the area to be sampled. An intake valve on the end of the elongated sampling tube is opened momentarily and a small sample of the atmosphere to be sampled is moved through the intake valve and the elongated sampling tube into an isolated metallic inner cylinder filled with metallic wool. An outer metallic cylinder is located concentrically around the inner cylinder and is electrically isolated therefrom except for a single discharge path through an electronic control package. Current flow between the inner cylinder and outer cylinder is measured by a sensitive ammeter in the electronic control package and is electronically converted to indicate charge density in coloumbs/meters.sup.3.