Abstract: The electrolytic resistivity leak detector comprises the method of electrical resistivity to measure the gradual intrusion of aggressive chemicals into the wall of a plastic or fiber reinforced plastic vessel. This device and method includes the use of electric sensors within the wall of the vessel. The sensors provide an electrical circuit as the chemicals permeate through the wall and make contact with the sensors. A microammeter is included as an instrument to monitor and register the degree of electrical resistivity caused by the chemical intrusion.

Abstract: An interchangeable pinch valve system (10) is provided with a valve body (20) having a longitudinal dimension which is substantially identical to standard longitudinal dimensions for ball, gate and the like type valves of similar flow path diameter. The reduced longitudinal dimension of pinch valve system (10), as compared to prior art systems, is achieved by a flexible-walled tubular sleeve (50) having a pair of transversely directed folds (60, 62) which provide sufficient sleeve material to enable the pinch closing of the flow passage (52) without substantially stretching the tubular sleeve wall (51). The valve body 20 is provided with a pair of recessed openings (22, 24) formed in the interior of valve body wall (21) in parallel spaced relation transverse to the fluid flow axis of the valve for receipt of the respective folds (62, 60), whereby the tubular sleeve (50) is in contiguous contact with the interior surface of valve body wall (21).

Abstract: An apparatus and method for detecting leaks in rubber or plastic articles such as surgical or examination gloves that, in general, are insulators against an electric current. The apparatus comprises a power source, first and second electrical leads, and structure for measuring the electrical properties between the leads. In the method of the invention the apparatus, together with an ion-containing liquid, complete an electrical circuit between the inside and the outside of the article when a hole in the article permits ions in the liquid to carry electrons through the hole. When used to test for holes in surgical or examination gloves during the use thereof or between such us as in the case of examination gloves, the test can be conveniently carried out while the practitioner washes or rinses his gloved hands under a non-recirculated stream of running tap water or flowing sterile saline solution.

Abstract: A method and apparatus for the non-destructive testing of a protective baer material. In a preferred embodiment, the method comprises applying an alternating electrical current across the protective barrier material for establishing a conductivity, G, of the protective barrier material and/or a quality factor, Q, of the protective barrier material. The conductivity, G, and/or the quality factor, Q, are measured at more than one frequency. The quality factor and/or conductivity measurements so obtained at the more than one frequency are compared to predetermined quality factor and/or conductivity limits.

Abstract: A leak detection system and method are disclosed. The capacitance of a leak detection cable is changed by a leaking liquid. A capacitance measuring circuit detects changes in the capacitance of the cable and thereby detects the presence of a leak. The capacitance measuring circuit includes an inverter, a current source, a comparator, and a timer. The inverter inverts a DC voltage to produce a mirror-image invented DC voltage. The current source produces a constant current proportional to the mirror image inverted DC voltage and supplies the constant current to the cable such that the cable is charged. A comparator compares the voltage across the cable to the input voltage and produces a match signal when they are equal. A timer which is responsive to the match signal measures the time required for the cable to be charged. The capacitance of the cable is directly proportional to the charge time.

Abstract: A method and apparatus for testing, in situ, for imperfections in an inert coating of a moving metal component of an apparatus (e.g. a metal basket of a centrifuge) involves covering the inert coating with an electrically conductive liquid, applying an electrical voltage across the inert coating while the apparatus is operational, monitoring the current or applied voltage, and utilizing the measured current or voltge to provide an indication of the condition of the inert coating. If the coating is defective, the conductive liquid will find its way into any flaws or imperfections, thereby providing a path of lower electrical resistance.

Abstract: A method and apparatus for determining the properties of a particular insulation layer wherein an ion source is directly at the insulation layer. An electrode is provided between the insulation layer mounted on a support, and the ion source. A voltage U is generated across the electrode and the support and a particular current ratio is maintained between the electrode, the voltage generator and the support by adjusting the voltage U. The time behavior of this voltage U would determine the properties of the insulation layer.

Abstract: This invention relates to an improved arm sleeve testing apparatus and method of testing such tubular sleeves to determine whether any flaws or defects exist in their sidewalls which would permit the conduct of electrical current. The sleeves are sealed at their lower smaller ends by an inflatable sealing member which seals the inner sidewall surfaces in pressure-tight relation within a non-conductive cup-like member. The sleeves are mounted on a vertically-reciprocatable platform in vertical relation over an insulated tank containing a supply of conductive liquid. A second conductive liquid is introduced into the sleeve and an electrical current of predetermined magnitude is passed between the two liquids with the sleeve sidewalls therebetween. Any defects or flaws in the sidewalls permit electrical current flow which is detected by a visual signal or by an audible alarm indicating the sleeve is unsatisfactory for use in handling live power lines, for example.

Abstract: A technique for measuring the insulation resistance of an insulated rail joint in the presence of leakage ground resistance (ballast resistance), as well as other track run-around paths, without the use of calibrated meters, such technique characterized by the use of a bridge circuit which includes a leg having the insulated joint therein whose resistance is being measured, the other three legs including a resistor of fixed known value and two variable resistors respectively, such that when the variable resistors are varied to obtain simultaneously both (a) the null of the rail, or ballast, current, and (b) ballast in the bridge circuit, the resistance value of the insulated joint is determined.

Abstract: A device for detecting insulation defects in a cable having a conductor while an electrical signal is impressed on the cable conductor, the device being composed of an ion source for generating an ion cloud and arranged for causing the ion cloud to be displaced along, and to envelop, the cable, a sense conductor arranged to be disposed along, and in proximity to, the cable and to be in communication with the ion cloud, and a plurality of coded position conductors arranged to be disposed along, and in proximity to, the sense conductor and to be in communication with the ion cloud, each position conductor having at least one discrete region covered with insulation arranged in a pattern which differs from one position conductor to another. An alternating signal having a respectively different frequency is applied to each position conductor, the frequency of the signal impressed on each position conductor being different from the frequency of the signal impressed on the cable conductor.

Abstract: A device for monitoring an electrical cable comprising a conductor surrounded by insulation to locate insulation defects while a signal is impressed on the conductor, the device including an ion generator for creating an ionized atmosphere to envelop the cable, a sense wire assembly disposed in the vicinity of the cable and within the ionized atmosphere so that the signal impressed on the conductor is coupled into the sense wire assembly when the ionized atmosphere envelops an insulation defect, and a circuit for monitoring the signal coupled into the sense wire assembly from the cable conductor. The sense wire assembly comprises a first wire presenting a low resistance to the ionized atmosphere, a second wire presenting a high resistance to the ionized atmosphere, and a circuit unit for producing a sense wire signal which is a function of the difference between the signal coupled into said first and second wires.

Abstract: A method and apparatus for testing the integrity of the dielectric coating on an elongated member. The apparatus includes a pair of opposing, conducting surfaces that can be biased against the dielectric surface, a source of high voltge that can be switchably imposed on the conducting surfaces, a ground for completing an electrical circuit between the elongated member and the source of high voltage, and an electrical circuit for detecting the passage of current through the electrical ground. A first visible indicator on the apparatus shows when the high voltage is applied to the conducting surfaces and a second visible indicator shows when a current is detected through the electrical ground. This apparatus allows the conducting surfaces to be moved longitudinally along the elongated member to test the dielectric integrity of virtually the entire dielectric surface in a single pass.

Abstract: A system for monitoring the continuity and potential rate of leakage of an underground tank hole liner formed of a sheet of electrically insulating polymeric material in which a standard current measurement is made of a circuit comprising a standard electrode in the form of a container of electrically insulating material having a small hole in a side thereof and containing an electrically conductive fluid connected to an injection electrode through a current source, the electrodes being immersed in a conductive fluid in the bottom of the tank hole to provide a calibrated liner leakage value, and such measurement is compared with the current provided by a circuit comprising the injection electrode connected to a ground electrode through the current source.

Abstract: The invention relates to a method for the determination of the condition of the insulation of an object (1) made of an electrically conducting material, coated with an electrical insulation (2) and positioned in an electrically conducting medium. According to the invention, the determination of the condition of the insulation is carried out without any electric contact with the object to be monitored in such a way that a first electromagnetic field (6) is created in the conducting medium (3), which field induces eddy currents (7, 8) both in the medium (3) and in the conducting object (1) positioned therein, a second electromagnetic field created by the eddy currents (7, 8) passing both in the conducting medium (3) and in the conducting object (1) is measured in the form of electrical information, essentially excluding the effect of the first electromagnetic field, and said electrical information is analyzed for detecting any changes in the condition of the insulation.

Abstract: A power cable such as a rubber or plastic insulated power cable is diagnosed to be detected an insulation deterioration resulted from water tree generated in an insulation material thereof. At first, charging current flowing from the power cable through a grounding conductor connected to a metal shielding layer thereof to the ground is measured under a state that a rated AC voltage is applied to the power cable. In accordance with the charging current, stray current flowing from the ground to the power cable is calculated. Then, a direct current component of the charging current is detected, and an intrinsic direct current component is calculated by subtracting the stray current from the direct current component. The insulation deterioration is diagnosed in accordance with the level of the intrinsic direct current component.

Abstract: A moisture presence alarm system has a sensor system which extends over an area to monitored and a detector device which receives signals from the sensor system. This has spatially separated conductors in contact with a moisture absorbent material. The position of the leak is determined by selective interrogation of pairs of conductors. The conductors may be in an orthogonal matrix (A1 . . . X1 . . . A2 . . . X2), each conductor (10,11) being associated with a moisture absorbent strip (12,13).

Abstract: An electrical insulation testing device has a voltage source 12 for applying a test voltage through terminals 14. Measuring devices 16 take measurements to enable the resistance of the insulation under test to be determined. Results are shown by a display 20. The controller 24 prevents the display of results until the voltage source 12 has been turned off and discharge circuit 22 has discharged the capacitance of the insulation under test. This prevents the insulation being left charged after the test. Measurement is commenced by operation of the switch 28. Only one measurement can be taken each time the switch 28 is closed.

Abstract: This invention is directed to detecting and locating leaks in geomembrane liners used to contain liquid or liquid-solid materials, such as in waste landfills and liquid impoundments. An array of electric or magnetic field detectors is placed on one side of the liner. The detector array is on a plane generally parallel to the liner, and the location of each detector is known. A voltage is impressed across the liner. When a leak occurs in the liner, a current flows through the leak, creating an electric field and a magnetic field around the leak. The existence of the electric or magnetic field is detected by the detector array, which indicates a leak. The leak is located with orthogonal measurements from selected detectors, and these measurements are used to geometrically locate the leak.

Abstract: A pinhole detecting apparatus includes a first electrode which may be a needle electrode or a brush electrode. The first electrode is positioned to be closed to or brought into contact with a member to be detected such as an insulation sheet which seals food, a closed container which contains medicine, or the like. Such a member to be detected is put on a second electrode which may be a conveyer made of electrically conductive material. When a high voltage is applied between the first and second electrodes, if a pinhole was formed on the member to be detected, a discharge current flows between the first and second electrodes through the pinhole, whereby the pinhole can be detected through detection of such a discharge current. A portion of the member to be detected below the first electrode is cooled by an air stream or other coolant when the high voltage is applied to the first and second electrodes, whereby the portion of the member to be detected is prevented from being thermally destroyed.

Abstract: A method and a measuring device for localizing a damage in a dielectric corrosion resistant layer of a pipe line are described, especially for an enameled pipe line, through which an electrolytically conducting fluid is passed. Localization is achieved by performing a potential difference measurement between two electrodes arranged at the begining and at the end of a supervised region along the length of the pipe line, to which preferably a constant current source is connected, the positive terminal of which is connected with the carrier material of the pipe line and the negative terminal of which is connected with the two electrodes. Preverably a calibration is performed by means of an additional electrode, which can be connected to the measurement region.

Abstract: Method and apparatus for detecting leaks in a rubber glove or the like. The wearer of rubber gloves connects a clip to his ear and places each glove-covered hand individually into electrolyte liquid in an electrically conductive receptacle. A circuit including a buzzer or beeper sounds if there is a leak in the glove. The circuit includes a clip connected to the wearer's ear as well as the beeper, the electrolyte, a battery and the receptacle. An alternative embodiment includes a removable disposable electrically non-conductive receptacle for the electrolyte liquid with the circuit including an electrical conductor cemented to the inside of the receptacle and in the circuit.

Abstract: A method and apparatus for monitoring the degradation of elastomeric materials is provided. Piezoelectric oscillators are placed in contact with the elastomeric material so that a forced harmonic oscillator with damping is formed. The piezoelectric material is connected to an oscillator circuit,. A parameter such as the resonant frequency, amplitude or Q value of the oscillating system is related to the elasticity of the elastomeric material. Degradation of the elastomeric material causes changes in its elasticity which, in turn, causes the resonant frequency, amplitude or Q of the oscillator to change. These changes are monitored with a peak height monitor, frequency counter, Q-meter, spectrum analyzer, or other measurement circuit. Elasticity of elastomers can be monitored in situ, using miniaturized sensors.

Abstract: A high frequency and two low frequency electromagnetic signals are generated (1), the low ones being coherent with the second being a sub-harmonic of the first. The high frequency is modulated (4) by the second low frequency and applied (7,9) as a composite signal to an underground conductor, while the first low frequency is applied (9,10) additively. A receiver traversed over the line has aerials (12,21) or ground probes (24,25) for picking up these signals in separate channels. The high frequency is demodulated (18) to provide a reference signal for a synchronous detector (20) to which the first low frequency is fed. That suffers a phase reversal if there is a fault, and the output of the synchronous detector is arranged to indicate that.

Abstract: A method and device for detecting defects in wire or cable insulation without disconnecting the cable by synchronously detecting the current in a sense conductor with respect to the potential waveform existing or imposed on the cable under test. Both the ion source and the sense conductor are placed in close proximity to the cable under test. The current flowing in the sense conductor due to the ions from the ion source varies depending upon the presence of defects in the cable insulation and the potential waveform present on the cable under test. The synchronous detection enhances the signal to noise ratio of the current measurement.

Abstract: An apparatus for detecting position of internal fault in a gas-insulated bus bar (1) comprises electrodes (30) each of which are provided in section of predetermined length along axial direction of the tubular-shaped housing and the electrodes (30) can detect changes of voltage of a conductor (3) in each section and thereby can detect a point of fault.

Abstract: Apparatus for separating the amount of resistive leakage current passing through an insulating portion (14) of an aerial boom (12) which is in contact with an electrical line includes a first current collector band (24) and a second current collector band (22). A first current path extends from the first current collector band to ground. A second current path extends from the second current collector band to ground. A first current flows through the first current path due to current that leaks through the insulating portion of the boom as well as capacitance effects. A second current flows through said second current path due to capacitance effects caused by nearby sources of extraneous ambient electrical energy. A converter box (44) converts the first and second currents into representative first and second voltage signals. The first and second voltage signals are transmitted to an electronics and readout box (70) by a pair of shielded cables (50 and 52) or other conventional means such as optical fibers.

Abstract: In an insulation testing device for testing insulation characteristics of a gas insulated apparatus, at least one pair of positive and negative polarity impulse voltages each having a duration shorter than a half period of a commercial frequency voltage are applied to the gas insulated apparatus by a test voltage generator.

Abstract: Dielectric testing of rubber or plastic gloves, particularly an apparatus for suspending a plurality of pairs of water-filled gloves, then immersing the gloves into a water test tank. A high voltage test circuit includes a source of electrical power connected to the water test tank and a plurality of individual electrodes extending into each water-filled glove. Individual test circuits for each electrode enable continued testing, notwithstanding failure or removal of any one glove.

Abstract: A system for determining the location of a leak in a pond liner made of electrically insulating material supported by a medium which is electrically conductive consists of a movable nozzle for directing a stream of an electrically conductive liquid against the liner, a ground electrode connected to the electrically conductive supporting medium exterior of the pond and liner, a current source connected between the nozzle and the ground electrode, and a galvanometer located in the electrical circuit comprising the nozzle, current source and ground electrode for monitoring at least one electrical property in the circuit when a change in an electrical property occurs as a result of the stream of electrically conductive liquid completing the circuit by contacting the supporting medium through a hole in the liner.

Abstract: A system and a method for measuring the leakage flow rate from an impounded liquid through a tear or hole in a geomembrane liner is set forth. It utilizes a narrowed passage connected with an inverted funnel to confine the flow, and further includes forming a transverse magnetic field thereacross, a sensor mutually perpendicular to the passage and the magnetic field and a voltmeter connected to the sensor for measuring the voltage. The voltage is dependent on the rate of flow of the leaked liquid along the passage.

Abstract: A method and apparatus for determining the rate of flow of a leak through a geomembrane is set forth. In the preferred and illustrated embodiment, a surrounding lower skirt having a peripheral weight thereabout is placed on the bottom to surround the location of the leak. The skirt supports a cover. A portion of the skirt or cover is made of an ionic and electrically permeable membrane to permit current flow. A second liquid is defined to be miscible with the first liquid and to have a markedly different electrical conductivity. The rate of flow of the second liquid out of the lower skirt and cover is determined by measuring the electrical potential between liquid in the impoundment and the second liquid within the skirt as the electrical conductivity of the surrounding earth is altered by invasion of the second liquid into the soil under the geomembrane liner. The apparatus utilizes a reservoir of the second liquid which is delivered through a suitable valve and fill hose into the lower skirt and cover.

Abstract: A leak detection and location method and apparatus for detection of perforations in a obscure geomembrane liner is set forth. In a typical application, upper and lower liners are positioned contiguous to one another and a conducting liquid is placed between them. In the event a tear or perforation is formed in the lower liner, a current flow path is established from a power supply and conductors connected to the power supply. The current flow path extends through the liquid to the leak. Because of the liquid path through the liner, electric current will flow through the perforation and establish an associated magnetic field in the near vicinity of the leak. Magnetic sensors are then swept across the surface of or through the impounded liquid above the liners to indicate such magnetic field variations and the locations of such perturbations correspond to the locations of the leak perforations.

Abstract: An AC ohmeter is adapted for testing insulated pipe flanges where flammable substances are involved. It employs a low frequency, low voltage oscillator and includes a precision rectifier. The output of the rectifier is smoothed and applied to a dual comparator circuit such that high, low and intermediate resistance readings are obtained.

Abstract: A tamper proof package for determining whether or not a package has been opened or tampered with before opening the package is provided. The package has an electrical conductor of known resistance which is so positioned that any attempt to open the package or to tamper with the contents destroys all or part of the conductor. The resistance of the conductor can be measured at the time of sale or during the shelf life of the package to determine whether or not the package has been opened or tampered with.

Abstract: A device for detecting water penetration into a marine acoustic streamer with segments interconnected by connectors. Each connector positioned between any two adjacent segments is provided with sensors which are constituted by flexible printed circuits having two distinct and interleaved conductive combs thereon. A bifilar line interconnects the sensors, and an emitting and receiving circuit allows a sensor whose impedance has been changed by the infiltration of water into the connector to be located by means of a reflectrometric method, whereby the operating condition of such marine acoustic streamer can be supervised efficiently and at low cost.