Abstract: A circuit and method for measuring the capacitance of a medium independent of the resistivity of the medium. A triangular voltage is applied to plates immersed in the medium to generate both a resistive current component in phase with the triangular voltage and a capacitive current component in phase with a differential of the triangular voltage. The resistive and capacitive current components are summed with a selectable current which is provided having a phase .pi. radians out of phase with the triangular voltage and having an amplitude related to a control signal. The summed current is sampled over a time period phase shifted from the capacitive current component and then integrated so that the capacitive current component integrates to zero and the integral of the resistive current component minus the selectable current provides the control signal. In response to the control signal, the selectable current is varied until the sum of the selectable current and resistive current component are nulled.

Abstract: A system for non-destructively determining the thickness of a coating on a metal substrate includes using a first probe to locally heat the coating so as to establish a temperature gradient therein. The probe is configured so as to also provide electrical contact to the coating surface. This first probe is formed from a material having high thermal conductivity, and is at least partially plated with a material having high resistance to oxidation. Preferably, the probe plating material is chosen to also have high resistance to mechanical wear. The testing system also includes an electrical power supply for controllably heating the first probe in order to maintain the temperature thereof at a constant predetermined value. A second probe provides an electrical return contact in order to form a circuit for measuring the thermoelectric voltage between the two probes. This thermoelectric voltage may be conveniently measured by an AC amplification circuit.

Abstract: Weak links in electrically continuous superconductors are detected by observing the effect of magnetic field modulation on the dc resistance of superconductors. The phase detected response to the magnetic modulation shows a peak at T.sub.c. The presence of a second peak at temperatures below T.sub.c, and concomitantly the appearance of a tail on the low temperature end of the dc resistance vs temperature curve indicates the presence of weak links in the superconductor.

Abstract: A parallel plate dielectric analyzer is disclosed including:(a) a distance sensor for accurately measuring the varying distance between the electrodes, such as a linear voltage differential transformer (LVDT), and means responsive to the distance sensor for positioning the electrodes;(b) a force transducer for measuring the applied force on the sample and means responsive to the force transducer to give a desired force by varying the electrode spacing;(c) disposable electrodes made using thick film technology composed of a ceramic substrate with a conductor adhered to its surface; and(d) a temperature sensor built into one of the electrodes such as a platinum ring adhered to the surface of one of the electrodes and means to measure the resistance across the platinum ring.

Abstract: A ceramic or other substrate is tested for dielectric constant K and loss tangent by placing it on a central transverse plane across a cylindrical waveguide. A swept-frequency signal is injected into the waveguide at an input coupling loop and is picked up at an output coupling loop. Maximum transmission through the dielectric substrate occurs at a frequency that depends on the waveguide radius, the substrate thickness, and the dielectric constant. The dielectric constant can be obtained from the resonant frequency of a predetermined transmission mode, e.g., the TE.sub.01 mode. The loss tangent can be calculated from the transmission bandwidth. The measurement of the dielectric constant is insensitive to the position of the substrate in the gap between waveguide sections, and thus intimate contact is not required.

Abstract: The invention relates to a device for measuring the impedance of a medium along a measurement line, the medium being either sea water or a sediment on the sea-bottom or else a mixture thereof. According to the invention, a special antenna (2) is used, which extends along the measurement line and contains a succession of ring electrodes (10, 11), which can selectively be fitted into a meter circuit (FIG. 2) via cyclically switched Reed relays (34, 35). The invention can especially be applied to the study of the alterations of a hole in a sediment at sea-bottom created behind a torpedo-shaped container penetrating by gravity into the sediment.

Abstract: Electrostatic discharge properties of materials are quantitatively measured and ranked. Samples (20) are rotated on a turntable (15) beneath selectable, co-available electrostatic chargers (30/40), one being a corona charging element (30) and the other a sample-engaging triboelectric charging element (40). They then pass under a voltage meter (25) to measure the amount of residual charge on the samples (20). After charging is discontinued, measurements are continued to record the charge decay history over time.

Abstract: Complex impedance measured over a predefined frequency range is used to determine the identity of different oils in a column. The location of an interface between the oils is determined from the percent frequency effects of the complex impedance measured across the interface.

Abstract: A manual apparatus for testing the vacuum of an evacuated vial. A cylindrical test enclosure having an access opening in the wall thereof is provided for the vial. A rotatable sleeve surrounds the enclosure and has a like access opening in registration with and rotatable to be in alignment with the access opening of the test enclosure. When the two access openings are rotated out of alignment, high voltage radio frequency power is applied to the exterior of the vial, and an intense flash of light occurs next to the vial to cause ionization of gas within the vial. The ionization current which results is indicative of the value of the vacuum within the vial.

Abstract: An indicator includes an indicating member driving unit, an encoder plate, a rotational position detecting unit, and an indication position control unit. The indicating member driving unit rotates an indicating member mounted on a rotor shaft in accordance with an electrical signal input to cause the indicating member to indicate. The encoder plate rotates in association with the indicating member. The rotational position detecting unit detects an actual indication position of the indicating member on the basis of a rotational amount of the encoder plate. The indication position control unit controls the indication position of the indicating member so that the actual indication position of the indicating member detected by the rotational position detecting unit coincides with an indication position of the indicating member determined in correspondence to the electrical signal input.

Abstract: A device for tracing preferably short-circuiting in electric systems.When tracing short-circuiting it is desirable that voltage and current will have normal values immediately after elimination thereof, for instance by contact. This object has been achieved in that an oscillator (23) limits the current at the output (19) to near 0 A as long as short-circuiting remains.When the short-circuiting ceases this is detected by a unit of sensitivity (24) and, as a result of this, the oscillation stops and preset current and voltage levels are entered immediately and automatically.

Abstract: A four terminal ohmmeter apparatus includes circuitry for blanking the meter read-out in the event one or more connections to a device or structure under test have been improperly made. The voltage drop between current terminals is determined and compared with a threshold value. The voltage drop between potential terminals or between potential and current terminals, as caused by a separate a.c. source, is also determined and compared with a standard. Individual indicators inform the operator of the validity of each connection in order that corrective action can be taken if necessary. Voltage inputs are also utilized for ascertaining whether a correct meter range is being used and for changing the range if it is improper.

Abstract: A dynamic state-of-charge indicator for a storage battery characterized by a discharge curve relating available energy of the battery to a contemporaneous voltage over a range of voltage boundaries having predetermined end points corresponding to fully charged and effectively discharged for one charge cycle. The indicator includes a microprocessor for storing predetermined relationships between the contemporaneous voltage and the state-of-charge of the battery. A voltage sensor and a current sensor are connected to monitor battery voltage and current flow, respectively, and to provide corresponding voltage and current signals to the microprocessor. The microprocessor periodically computes the internal resistance of the battery, the average voltage and current for a predetermined discharge time period and a corrected voltage as a total of internal resistance voltage loss and average voltage with the state-of-charge being determined as a function of the corrected battery voltage.

Abstract: A microvertex particle detector for use in a high energy physic collider including a plurality of parallel superconducting thin film strips separated from a superconducting ground plane by an insulating layer to form a plurality of superconducting waveguides. The microvertex particle detector indicates passage of a charged subatomic particle by measuring a voltage pulse measured across a superconducting waveguide caused by the transition of the superconducting thin film strip from a superconducting to a non-superconducting state in response to the passage of a charged particle. A plurality of superconducting thin film strips in two orthogonal planes plus the slow electromagnetic wave propogating in a superconducting transmission line are used to resolve N.sup.2 ambiguity of charged particle events.

Abstract: At least a pair (4) or a band of wires of an electrically conducting material is longitudinally embedded in the fiber composite material forming the building element (2) and firmly secured to the fiber composite material over the whole length of the wires. A weak current source (7) is connected to the free ends of the wires. The current conduction is then monitored, the capacitance is measured or the current conduction and the capacitance are measured.

Abstract: In order to test conductors on substrates for current constricting defects, such as cracks, narrow conductors, line breaks and intermittent opens, a test signal combining two alternating current signals at different frequencies and direct current offset signal is applied to the conductor. Upon encountering a defect, intermodulation signals are generated and detected. The phase of the detected signal and the phase of a reference signal are compared. The difference between the phase of the two signals is indicative of the presence of a defect in the conductor. The invention has particular application for testing thin conductors.

Abstract: In a metering pulse generator, a metering element engages a spring member to effect a gradual bending movement in one direction followed by a rapid return movement during which a pulse signal is developed by a piezoelectric material on the spring member . Energy is absorbed during each such rapid return movement of the spring member to provide damping, inhibit oscillations and effect reliable generation of a single pulse signal which is applied to an amplifier for transmission to a monitoring station.

Abstract: A method and an apparatus for determining angular velocity from two voltage signals which are produced by an angle transmitter (1) have a sinusoidal function with respect to the angle of rotation of a rotatable member and are shifted in phase by 90 angular degrees. The amount and sign of the angular velocity (.omega.) are determined by the division of the derivative of a first voltage signal with respect to time by the second voltage signal. In that signal range in which the second voltage signal has passages through zero, the derivative of the second voltage signal with respect to time is divided by the first voltage signal. Alternatively, the amount of the angular velocity (.omega.) is determined from the vector sum of the derivatives of the two voltage signals with respect to time. The sign of the angular velocity is determined from the two voltage signals and their derivatives.

Abstract: A device is provided for estimating the electromagnetic characteristics of a dielectric or magnetic material by means of a hyperfrequency electromagnetic wave which device comprises a coaxial line formed of a tubular body (2,3) and a core (1), which are rigid and coaxial with, at one end, a housing such that the external and internal peripheries of an annular sample piece (17) are respectively in tight friction contact with the inner surface of said tubular body and with the external surface of said core, said tubular body being formed of two parts which can be assembled together.

Abstract: Quadrature input signals from an opto-electronic or magnetic readhead which is movable relative to a periodically marked scale, are respectively multiplied by quadrature reference signals from a reference oscillator in multipliers. The resulting signals are added together in a mixer to give a signal (S) having a frequency which is the reference frequency shifted by the frequency of the input signals. This signal (S) is then compared with the reference signal. The reference signals are generated from a high frequency clock which is subsequently used to compare the period of the reference signal with that of the signal (S), giving outputs which interpolate the position of the readhead within the pitch of the marks on the scale.