Abstract: Highly accurate time interval measurement is achieved for an electrical waveform. The electrical waveform is sampled and converted to a series of voltages, and the series of voltages is interpolated in order to form a time tag list, using interpolations that are optimized for time interval measurement and analysis. The time tag list accurately represents the times at which particular events of interest occur, and is used to generate displays and results analysis such as adjacent cycle jitter and accurate differential triggering and analysis.

Abstract: A system and method for measuring phase-angle in electrical power systems includes inputting a reference signal into a receiving terminal of a communication system at a reference station and then sending the reference signal through the communication system. The reference signal is received at a substation and shaped as a quasi-reference signal. A phase difference .beta. between the quasi-reference signal and a tested signal at the substation is then measured. Phase delay of the reference signal caused by the communication system, including phase delay produced from sending means, receiving means, relaying units, and communication channels, is calculated. A phase difference .alpha. is then calculated between the reference signal and the tested signal according to the phase difference .beta. between the quasi-reference signal and the tested signal and the phase delay of the reference signal caused by the communication system.

Abstract: In a measurement system for electric disturbances in a metalen-capsulated high-voltage switchgear having at least one measurement probe for each phase for decoupling of electromagnetic interference signals, both the interference signals and the useful voltage are scanned by the same measurement probe in each phase, and both are made accessible, separately from one another, at a filter arrangement.

Abstract: A tester for power transformers and capacitors includes a pulse generator for applying a pulsating test signal to a pair of test leads which may be connected across the terminals of the device to be tested. Also connected across the test leads are a capacitor detector, an inductor detector and a continuity detector. If the connections to the transformer or capacitor in the device to be tested are good, the capacitor detector and inductor detector will distinguish one from the other and indicate that its condition is good. If the connections to the device are not good, the continuity detector will indicate whether there is a short circuit or open circuit condition. The detectors are coupled through control logic circuitry to an indicator circuit including a horn and blinking lights for providing unique indications of capacitor okay, inductor okay, short and open conditions. The capacitor detector provides a discharge path for a capacitor and detects the discharge current flow.

Abstract: A method and apparatus for determining the center frequency of a bandpass filter. The center frequency of a bandpass filter is determined by applying a bias voltage to a bandpass filter circuit receiving a pair of differential input voltages and producing a pair of differential output voltages. The differential output voltages are modified to exhibit a notchband magnitude characteristic. A minimum value of the differential output voltages exhibiting the notchband characteristic over a predetermined range of frequencies is determined and corresponds to the center frequency of the bandpass filter.

Abstract: An improved time domain reflectometer (TDR) includes a capacitor coupled in series between a transmission medium under test and the TDR receiver input. A switch, operating under microprocessor control, selectively couples and uncouples the capacitor to a voltage reference, such as ground. During the generation of interrogating pulses from the TDR and the acquisition of data from the transmission medium under test, the capacitor is uncoupled from the voltage reference and acts as a DC blocking capacitor. During periods of non-TDR activity, the capacitor is coupled to voltage reference and acts as a load for low frequency interference appearing on the transmission medium. The capacitor-switch operation blocks low frequency interference signals from the receiver input of the TDR.

Abstract: A method and apparatus for measuring at least one parameter including mass flow rate or moisture content of material moved by a conveyor are disclosed herein. The method includes the steps of applying an electric field to the material using a non-intrusive sensor assembly, generating signals related to the dielectric value of the material, and processing the signals to determine the parameter. The apparatus includes a capaciflector sensor assembly located along a surface of the conveyor to generate an electric field applied to the material and a processing circuit to determine the parameter based upon the signals output from the sensor assembly. The sensor assembly includes a first conductor spaced between a stationary member of the conveyor and the material, and a second conductor spaced between the first conductor and the stationary member to act as a shield for reducing parasitic capacitance between the first conductor and a reference plane.

Abstract: An electric meter tamper detection system for sensing removal of an electric meter from a corresponding meter socket and for generating a tamper signal is disclosed. In this system, the tamper signal is relayed to a headend when the electric meter--connected in series with and monitoring current flow through at least one conductor--has been removed from the meter socket. At least one resistor is electrically connected to the line-side of the conductor. A light emitting diode is electrically coupled to the resistor and to the load-side of the conductor. A transistor receives the tamper signal from the light emitting diode when the electric meter is removed from the meter socket. A microprocessor is coupled to the transistor, receives the tamper signal from the transistor, and relays the tamper signal to said headend. Thus, the headend is immediately notified if and when the electric meter is removed from its meter socket.

Abstract: A method for determining the shielding effectiveness of a shielded and, particularly, permanently installed cabling path wherein the cabling path has an inside conductor connected via a patching cable at a first end to a transmitter which emits an electrical test signal. One pole of the transmitter output is applied to ground potential and the other pole is conductively connected to a patching cable. At a second end of the cabling path the shielding is applied to ground potential and conductively connected to the inside conductor via a terminating impedance. The shielding of the cabling path is connected to that pole of the transmitter output applied to ground potential. It is connected thereto by a return line which is connected to the first end of the cabling path at a differential current intensity of the currents flowing through the patching cable and the return line is converted into a measured value using a measuring device.

Abstract: A thermoelectric measurement converter is disclosed, which forms the output signal as the product of the instantaneous values of two input signals; wherein the measurement converter comprises at least one electronic resistor and at least one temperature sensor, both being disposed on a common base which is heat insulated with respect to the environment.

Abstract: A streaming current sensor on which the placement of the sample outlet lower on the vertical axis than the sample inlet so as to increase the accuracy, reliability, and sensitivity of the sensor in comparison to those of the prior art, by enabling contaminants within the sample fluid to be removed from the buffer space before coming into contact with the sensing electrodes. The sensor further has a buffer space enabling the fluid to become a homogenous mixture of sample fluids before contacting the electrodes, thus increasing signal stability.

Abstract: A device (16) for sensing current flowing in a generally flat plate structure (10) contains a magnetic head (18) and signal processing circuitry (20). The magnetic head (a) senses changes in current-induced magnetic flux as the head is positioned over the plate structure and (b) provides a head output signal. The signal processing circuitry processes the head output signal to produce a data signal indicative of how much current appears to flow in the plate structure below the head. A driving voltage, which typically varies in a periodic manner to produce a characteristic signature, is applied to a primary conductor in the plate structure. A location sensor, typically formed with a light source (100) and a light sensor (102), detects the position of the magnetic head relative to the plate structure. A gas-cushion mechanism (80-98) controls the height of the head above the plate structure.

Abstract: A microwave microscope for measuring electrical characteristics of a sample, such as a semiconductor wafer, with fine resolution. A probe includes a microwave waveguide capable of supporting the two lowest orthogonal modes from a microwave source, e.g. of millimeter radiation. The probe tip includes a thin conductive wall formed at the probe end of the probe. Two perpendicularly arranged slits, that is cross slits, are formed in the conductive wall, each slit having a length nearly resonant with the microwave radiation and a width substantially smaller, e.g. of the order of 100 .mu.m, and of a size such that the radiation of the proper polarization nearly transparently passes through that slit. The sample to be tested is placed in the near field of the probe tip and scanned relative to the probe. Probing microwave radiation having the polarization which passes through one slit is launched in the waveguide. A non-rotated polarization component is reflected back from the sample through the same slit.

Abstract: A diagnostic device and associated operational procedure are used to both verify the integrity of components of high intensity discharge light fixtures and also troubleshoot problems in the wiring connecting the light fixture to the AC power source (transformer). The diagnostic device is a rugged, self-contained unit that can be connected across the ballast in the fixture for verifying component integrity, while also being adapted to load the AC power line that powers the fixture to detect problems in the wiring between the AC power source and the fixture.

Abstract: A probe tip for connecting an instrument to a circuit under test is disclosed. The probe tip is interchangeable with other probe tips to provide different attenuations of the signal under test to the instrument. The signal from the circuit under test is coupled to the instrument via a cable. The probe tips have a compensation network that cancels the effects of cable loss. The probe tips provide attenuation by using the probe tips internal impedance, and the characteristic impedance of the cable, to form a voltage divider.

Abstract: In one embodiment of the present invention, a distributed electronic system includes a plurality of electronic modules. Each of the electronic modules is coupled to one battery in a series connection of batteries. The electronic modules are coupled to a central controller via a data bus. Addresses are assigned to the electronic modules based on the potentials of corresponding nodes within the modules.

Abstract: The present invention provides a system and method for monitoring an electrical signal appearing on a rotating machine shaft. The system comprises a probe assembly for placement against the rotating machine shaft that is in electrically conductive contact with the shaft. The probe assembly includes at least one circuit for receiving the electrical signal from the rotating machine shaft and producing various electrical signals that are read by a data processing system, which is coupled to the circuit. The data processing system determines from the electrical signal obtained from the circuit, the RMS AC voltage, DC voltage, peak voltage, and the RMS AC and DC current through two different resisters that are all appearing on the rotating machine shaft. The data processing system also performs Fast Fourier Transforms on the RMS voltage and current signals and produces a frequency spectrum over time.

Abstract: A diagnostic tester for use with a lighting system having at least one lamp, a ballast, a capacitor, and a plurality of wires interconnecting the lamp, ballast, and capacitor. A diagnostic receptacle is electrically coupled to the lamp, ballast, and capacitor. A connector is adapted to engage the diagnostic receptacle and provide an electrical connection therewith. The connector is electrically coupled to circuits for testing the ballast, the capacitor, and the plurality of wires in the lighting system. An indicator is provided for separately indicating whether the ballast, the capacitor, and the plurality of wires are functioning properly. An indicator may also be employed with a pair of terminals on the tester housing for testing the continuity of a lighting system fuse.

Abstract: In a method and a system for the operation of a resistive moisture sensor, conductance of the sensor is measured, whereby current through the moisture sensor is measured preferably during an application of a voltage to the moisture sensor. In order to avoid electrolytic phenomena, the voltage is fed to the moisture sensor via a capacitor, and has a waveform of two pulses of different polarity following shortly one after the other.

Abstract: In a network analyzer having one or two test ports each of which is connected via fourports to measuring points the measured values of which are analyzed in an evaluation means that includes a memory for storing system errors which have been determined during a calibration operation and must be taken into account for the object measurement, there is provided a calibration twoport between at least one of said test ports and said fourport of the associated measuring points, said calibration twoport being adapted to be switched from a basic state to two further switching states, and said calibration twoport differs in one of said further switching states from the basic switching state at least in transmission and in the other one of said further switching states differs at least in reflection from the basic switching state.