Abstract: A method for measuring the resistance or conductivity between two or more conductors which are placed against a semiconductor element, the conductors are placed either in contact with the top surface or one conductor is placed in contact with the top surface and the other conductor is in the form of a large ohmic contact applied to the bottom surface of the semiconductor element. In order to bring the contact resistance between the top conductor(s) and the element to, and hold it at, a predetermined value during measuring, the conductor(s) are held at a constant distance and/or under constant pressure relative to the semiconductor element by use of a scanning proximity microscope. The top conductor may have a boron implanted diamond tip. The carrier profile of the semiconductor element is determined from previously derived calibration curves.

Abstract: The present invention is a device for measuring the electric surface charge density on each surface of a sheet. The sheet can either be moving or non-moving. If the sheet is non-moving a pliers-like device having a pair of electrodes aligned opposite with each other is used. The sheet is placed between the electrodes and the surface measurement is made by either one or two electrometers. For a moving web, the apparatus includes a first and second roller each having a charge measurement segment electrically isolated from the roller shell wherein the charge measurement segments periodically engage the web running through the two rollers. Two grounded shields which periodically shield the charge measurement segment are provided. Two electrometers are provided and from this surface charge density measurement and net charge density measurement on the moving sheet are obtained.

Abstract: To increase the measuring sensitivity of a simple-to-manufacture, multi-faced solid optical current sensor, at least one of the light-reflecting lateral faces is displaced radially inward with respect to the remaining light-reflecting lateral faces and has a lesser minimum distance from a center of the solid optical current sensor than the other lateral faces. Because of this displacement, the incident light beam does not move through a closed polygonal progression in the course of a single circuit around a recess for a current conductor, whose current intensity is to be measured by means of the Faraday effect. Helically overlapping displacements of the light circuit paths are created, which cause an increase in light sensitivity. The lateral face or another lateral face can also be displaced outwardly instead of inwardly.

Abstract: Novel conductive liquid compositions which have low resistivity when carrying an applied steady-state current (I.sub.Steady-State) but exhibit sharp increases in resistivity when subject to an applied fault current (I.sub.Fault). When used in circuit protection devices, the novel conductive liquid compositions having low resistivity are contained within an elongated flexible tube sealed by electrodes electrically connected to a load of an electrical circuit. The conductive liquid compositions carry an applied normal current under steady-state conditions.

Abstract: Method and apparatus for obtaining the average aspect ratio of non-spherical particles in suspension. The particles are caused to orient generally in one direction and the conductivity of the particles are measured in such direction while simultaneously measuring the conductivity of the particles in a traverse direction. The difference between the two conductivity measurements is indicative of the average aspect ratio of the particles in suspension.

Abstract: A method is provided for the monitoring of a moving medium (1), in particular the measurement of the filling level in a container or the distance signal of an object (1) to be detected where a sensor (2) is employed. The sensor (2) is subjected at its input to a supply voltage source (Ubs) or a supply current source. In order to suppress relatively slowly changing interfering values, the output signal (Uas) of the sensor (2) is fed back in a feedback loop to the input of the sensor (2) or, respectively, to the supply voltage of the sensor (2). The feedback loop is formed such that the input supply voltage source (Ubs) of the sensor, which is changeable for adjustment of the sensitivity, changes in dependence on the output signal (Uas) of the sensor (2) such that a constant sensitivity is present at all times. In case of an occurrence of a sufficiently fast or, respectively, sufficiently jumpy change larger than 0.01 V/sec.

Abstract: A capacitance measuring device incorporates the integrating analog-digital converter circuit of a handheld meter. The capacitance measuring device charges an unknown capacitance with a constant current until the voltage across the unknown capacitor reaches a predetermined voltage. At the same time, a reference voltage is applied to the input lead of an integrating circuit of the integrating analog-digital converter such that a corresponding proportional charge is stored in the feedback capacitor of the integrating circuit. The negative of the reference voltage is then applied to the integrating circuit so that charge is removed from the feedback capacitor at the same rate as the feedback capacitor was charged. A counter is used to determine the number of clock pulses it took to completely discharge the feedback capacitor and hence a reading of the unknown capacitance can be determined from the equation C.sub.X =I.sub.CHARGE *T.sub.2 /V.sub.TRIP.

Abstract: A tester contact for providing a reliable test interface between electrical test equipment and a test item. The tester contact consists of two contact beams partially mounted within a contact body. Each of the contact beams has a first end, a second end, and is constructed of a resilient metal material.

Abstract: A method and a fault sensor device (1) which can detect and distinguish abnormal current and voltage events on an alternating current overhead and underground transmission line or distribution line (2). The fault sensor device (1) is contained in an elongated molded plastic housing (4), The fault sensor device (1) includes a current sensor (12) and a voltage sensor (14) connected in proximity to the transmission or distribution line (2) for monitoring current and voltage analog signals; an analog-to-digital converter (22) connected to the current and voltage sensors (12,14) for sampling the current and voltage analog signals and producing: corresponding digital signals; a processor (11) responsive to the digital signals for detecting an abnormal condition and distinguishing whether any of a plurality of types of faults has occurred; and a transmitter (3) for transmitting the fault information from the processor (11) to a remote location.

Abstract: A universal cable connector includes a plurality of different sized connectors adapted to mate with the proximal connectors of different sized implantable stimulation leads. The cable connector attaches to a system analyzer and enables the system analyzer to interface with whatever implantable stimulation leads are connected to the connector block, thereby allowing the system analyzer to perform desired tests, such as threshold-determining tests, using the implanted stimulation leads. An adapter cable and clamp is also provided that allows an electrical connection of the proper polarity to be established between an implantable stimulation device, e.g., an implantable cardioverter-defibrillator (ICD), and the connector block while the implantable stimulation device is connected to a patient and is operating, thereby permitting the system analyzer to monitor the performance of the implantable stimulation device.

Abstract: A continuity/leakage tester for cardiac catheter probes of the type having plural spaced surface electrodes thereon. The apparatus includes a block having an open ended blind bores provided therein sized for receiving catheters of different diameters. A port is provided in the bore or bores adjacent the opened end and a spring loaded electrical contact provided therein which is grounded. Four plural bores are provided in the block, a common electrical conductor bar extends transversely across the ports which are formed at a common longitudinal station on each of the bores. The catheter is inserted in the bore and as each surface electrode contacts the spring biased electrode in the bore, a continuity test may be performed by an ohm meter connected to the probe lead for that particular surface electrode. As each subsequent surface electrode on the probe enters the bore, its corresponding electrical lead may be switched to the ohm meter for continuity testing of that electrode.

Abstract: An improved armature testing apparatus and method are provided. The individual resistances of two commutator bar lead connections can be simultaneously measured in a single measurement step. Further, the resistances of two armature coil can be determined in the same step. The present invention makes it possible to measure individual commutator coil lead connections more quickly than was previously possible.

Abstract: A termination control circuit is coupled to a far end of a cable. A modulated test signal is reflected back to a near end of the cable at a different frequency but at substantially the same level of attenuation as the test signal. Signal attenuation in the reflected signal is then measured to determine the amount of attenuation in the test signal. A second embodiment of the termination control circuit measures crosstalk by enabling and disabling termination resistors at the far end of the cable. A DC bias voltage located at the near end of the cable selectively turns on switching diodes to enable the termination resistor. Alternatively, both the attenuation and crosstalk circuits are combined together allowing both signal attenuation and crosstalk measurements with the same termination control circuit.

Abstract: The invention relates to a method for measuring a resistance value in a network incorporated in an electrical apparatus, wherein the network has at least two accessible terminals, the network has at least two time constants differing mutually by at least one order of magnitude, and the resistance value can be related to the voltage applied to the terminal clips and the current flowing through the apparatus.Such control switches are poorly accessible.Direct measurement is time-consuming as a result of the large value of the time constants. These problems are diminished by applying a step-like change of the voltage to the terminal clips, measuring the current flowing through the terminal clips before the change has taken place and after the transient phenomenon related to the smallest time constant and caused by applying the change is damped, and calculating the first resistance value from the measured values of the current.

Abstract: A fluid detection system capable of detecting the smallest amount of liquid chemicals, mixtures, aqueous solutions, pure water and others by detecting very low levels of resistance or conductance due to ionization when the liquid substances are subjected to very small amounts of electrical power in a small and localized sampling area. The system includes an electronic control module and a sensing probe. The control module provides strictly limited and controlled amounts of electrical voltage and current to one or more remotely located sensing probes which detect the level of resistance or conductance between two electrodes (gold pins) disposed at a fixed distance from one another. The voltage developed across the electrodes is input to a comparator circuit in the electronic module and compared to a reference to produce a signal defining either a dry or a wet (leak) condition of the sensing probe. This signal can be utilized to generate shutdown signals and/or audible and visual alarms.

Abstract: Procedures and apparatuses for determining the integrity of a geophysical barrier are provided. In particular, an electropotential gradient is established across the barrier in an attempt to drive ionic species through the barrier. The resulting ionic transport results in a current which can be measured between the electrodes, and which can be correlated to the integrity of the barrier. The location of a leak in the barrier can be determined by the use of an electromagnetic sensor which detects an anomaly in the flux field associated with the current.

Abstract: An electronic circuit for measuring current in a working circuit is provided with a first operational amplifier having a positive input, a negative input, and an output connected to at least one in-line amplifier to form a first current path. A second operational amplifier having a positive input, a negative input, and an output connected to a differential amplifier is provided within the circuit to form a second current path. An input terminal is connected to the negative inputs of each of the operational amplifiers to provide a connection between the electronic circuit and the working circuit. A variable conductance component is connected in series between the input terminal and the negative input of the second operational amplifier to control the flow of variable currents through the two current paths.

Abstract: A pulsed rare gas photoionization detector apparatus is set forth and incorporates a closed chamber for receiving a carrier gas flowing there through between inlets and outlets, and the carrier gas is exposed to a pair of electrodes forming a spark across the chamber and through the carrier gas. One component of the carrier gas is a dopant which selected from a plurality of rare gases. The sample to be analyzed is injected into the closed chamber where it commingles with the carrier gas. One reaction involves the formation of selected dopant in an excited state, which upon decay, serves as a source of ionizing radiation which reacts with sample compounds producing detectable events. These events are used to identify and quantify unknown compounds contained in the sample. The methods and apparatus are especially useful in selectively ionizing the compounds to be measured while not ionizing other constituents of the sample. This greatly enhances the signal-to-noise ratio for detecting impurity compounds.

Abstract: Development of worst case operating environment, interfering parameters of a test item, is effected by a decoupling device. The device includes a series of resonators configured and interconnected in a particular manner along with a shunt capacitance. Each resonator has a torroidal core formed from a ferrite composition. When connected between the test item and its support system, the device provides such an impedance to signals other than those needed for normal operation, that the highest noise voltage levels emit from the test item. These levels permit developing repeatable worst case interference parameters which provide a guide for modifying the test item circuit components and connectors so as to minimize the effects of generating EMI sources or to immunize susceptible receptors within the test item.

Abstract: The present invention relates to a method and related apparatus for the nondestructive determination of n layers of coating of a target having n layers of dielectric coating applied to an electrically conductive base material, comprising; a generator of electromagnetic waves in the microwave frequency range, including a microwave oscillator, a waveguide attached to the oscillator output and having an output aperture, a voltage detecting diode disposed within the waveguide, a flat layer of material adapted to be placed in a position abutting the target and disposed over the aperture of the waveguide and having a thickness t which, together with the waveguide, will provide a fixed distance between the diode and the target, and a display responsive to the output of the detecting diode for indicating the layer characteristics of the dielectric coating on the electrically conductive base material.