Abstract: A wind turbine hub (8) and nacelle (4) assembly including lightning conducting means (26, 30, 32, 40) for conducting lightning between the hub (8) and the nacelle (4), the hub (8) being mounted for rotation relative to the nacelle (4) and being adapted to support turbine blades, the hub (8) including a hub conductor (26) for connection to a turbine blade supported by the hub (8), the lightning conducting means including a conductive track (40) and a terminal (30, 32) which confront and are displaceable relative to each other, one of the conductive track (40) and the terminal (30, 32) being mounted on the hub (8) and being electrically connected to the hub conductor (26) and the other of the conductive track (40) and the terminal (30, 32) being mounted on the nacelle (4), the terminal (30, 32) including a terminal main body (30) which is spaced from the conductive track (40) and a sacrificial conductive terminal extension (32) extending from the terminal main body (30) towards the track (40).

Abstract: A voltage detection device includes voltage detection sections that measure cell voltages in the blocks, a control section, and (N?1) or less converters that raise the voltage, which is supplied from a DC power source, to a voltage of a driving power source for the voltage detection section. In a case where a voltage detected by at least one voltage detection section among the voltage detection sections which operate by the power supplied from the respective converters, exceeds a predetermined threshold value, the control section controls at least one voltage detection section among the voltage detection sections to operate using the cell voltage of each of the blocks as a driving power source and acquires the cell voltage in each of the blocks.

Abstract: An electrostatic sensor device including a first sensor element and a second sensor element; a dielectric substrate material formed in two layers, and a sensing hole which penetrates the dielectric substrate material from its upper surface to its lower surface. The first sensor element is receivable in the sensing hole; and second sensor element includes a first conducting ring disposed on an upper surface of said dielectric substrate and surrounding said sensing hole. The second conducting ring is disposed on a lower surface of the dielectric substrate and surrounds the sensing hole. The first sensor element and the second sensor are capable of producing a variable response when the first sensor element is disposed in the sensing hole.

Abstract: Apparatus and methods enabling the improved noninvasive measurement of electric currents flowing in the body of a human being or animal or in a biological sample by means of a modular array of primary source mirrors and a magnetometer.

Abstract: The invention generally relates to a blade for a wind turbine, and to a blade for a wind turbine comprising a lightning measurement system. In particular, a lightning measurement system is provided, comprising a lightning current sensor located in the blade for more accurate lightning measurements. A method of measuring a lightning strike is also provided.

Abstract: A reverse bias voltage is applied to a photodiode array provided with a plurality of avalanche photodiodes operated in Geiger mode and with quenching resistors connected in series to the respective avalanche photodiodes. Electric current is measured with change of the reverse bias voltage applied, and the reverse bias voltage at an inflection point in change of electric current measured is determined as a reference voltage. A voltage obtained by adding a predetermined value to the determined reference voltage is determined as a recommended operating voltage.

Abstract: A method for locating sub-surface natural resources. The method utilizes lightning data to discern relatively likely locations for finding the sub-surface natural resources.

Abstract: Detection of fault occurrences within a power distribution system. A transient detector and fault classification system (10) implements an algorithm that detects transients which may result from the occurrence of a fault in the power distribution system. The system includes a detection module (18) which processes a set samples obtained from electrical waveforms propagated of through the power distribution system and appear to be statistically anomalous compared to other sample data. This is done using an adaptive detection algorithm that is applied when large changes occur in a waveform over a relatively short period of time. The identified samples are then provided to a signal classifier module (20) which processes sets of samples to classify a transient they represent as a likely fault occurrence or some other type of anomaly which is likely not a fault occurrence.

Abstract: A battery connector includes: a plurality of terminals, each of which is to be connected to each electrode of a plurality of batteries; a plurality of voltage detection terminals, each of which is connected to respective one of the terminals, and includes a wire connection part to be connected to an electric wire; and a case which contains the plurality of terminals and the plurality of voltage detection terminals therein. Adjacent terminals of the terminals are fixed in the case to be spaced from each other, and an individual wire path of a wire routing part is provided between the adjacent terminals. Each of the voltage detection terminals is fixed so as to incline the wire connection part with respect to the individual wire path and to locate the wire connection part more interiorly than an edge of the case.

Abstract: A container for measuring cellular electric potential after being mounted on an electric potential measuring device is provided comprising a container and an electrode substrate, the electrode substrate being attached to a lower end of the container so as to form a plurality of wells, wherein the container comprises a plurality of cylindrical portions whose upper and lower ends are open, the electrode substrate comprises a substrate and a plurality of measurement electrodes and a plurality of reference electrodes disposed on one surface of the substrate, the measurement electrodes and the reference electrodes at least comprise metal-plated copper wiring, a pair of a measurement electrode and a reference electrode are disposed on a bottom of each well, and the measurement electrodes and the reference electrodes are formed by a pre-plating method.

Abstract: A method of detecting a detection target using a sensor requires a sensor having a transistor selected from the group of field-effect transistors or single electron transistors. The transistor includes a substrate, a source electrode disposed on the substrate and a drain electrode disposed on the substrate, and a channel forming a current path between the source electrode and the drawing electrode; an interaction-sensing gate comprising a specific substance; and a voltage gate. The method includes (a) providing the detection target on the interaction-sensing gate; (b) setting the gate voltage in the voltage gate at a predetermined level; (c) selectively interacting the specific substance with the detection target; (d) when the detection target interacts with the specific substance, changing a gate voltage in the voltage gate to adjust a characteristic of the transistor; and (e) measuring a change in the characteristic of the transistor to determine a presence of the detection target.

Abstract: A solar panel smart sensor system is disclosed. The sensor system permits solar power system owners and operators to monitor the voltage of individual panels in a solar array. The system uses a low wire-count bus in which the order of sensors on the bus is automatically determined. A novel technique is used to measure DC voltages of panels that may be floating hundreds of volts above ground. Bypass diodes are monitored to detect lost power generation capacity.

Abstract: An unadjusted ion population is obtained by measurement of an unadjusted charge transfer due to an imposed electrical potential between two surfaces within a plant. An adjusted ion population is determined by dividing the unadjusted charge transfer by the wetted surface area through which the charge transfers occurs. Changes in wetted surface area are measured by changes in the electrical capacitance of the surface/liquid interface. The type of ion is identified by application of a sequence of potential values imposed on the two surfaces by a source which permits the potential of the electron emitting surface to take on a value set by the ion involved in the electron transfer. The ion is identified by the value of this potential.

Abstract: Methods and devices to measure voltage margins of electromechanical devices are disclosed. The voltage margins are determined based on responses to test voltages which cause the devices to change states. State changes of the devices are detected by monitoring integrated current or charge used to drive the devices with the test voltages.

Abstract: According to an embodiment, a solar cell string 8 including solar cell modules 1 connected in series and each configured to generate DC power by being irradiated with light; and a junction box 2 configured to receive the DC power from the solar cell string are included. The junction box includes: a DC detector 10 configured to detect a current flowing through the solar cell string; a measurement device 11 configured to measure a current value of the current detected by the DC detector; and a data transmitter 12 configured to send the current value measured by the measurement device.

Abstract: A photovoltaic system includes multiple strings of solar panels and a device presenting a DC load to the strings of solar panels. Output currents of the strings of solar panels may be sensed and provided to a computer that generates current-voltage (IV) curves of the strings of solar panels. Output voltages of the string of solar panels may be sensed at the string or at the device presenting the DC load. The DC load may be varied. Output currents of the strings of solar panels responsive to the variation of the DC load are sensed to generate IV curves of the strings of solar panels. IV curves may be compared and analyzed to evaluate performance of and detect problems with a string of solar panels.

Abstract: Described are methods and apparatuses, including computer program products, for detecting lightning activity. Waveform data indicative of lightning activity is received by a waveform sensor from one or more signal converters. The waveform data comprises a group of electromagnetic waveforms. The waveform data is filtered by a processor to remove noise frequencies. One or more uncompressed portions of the waveform data are transmitted to a processing server. Digital filter data based on the one or more uncompressed portions of waveform data are received from the processing server. One or more frequencies are removed from the waveform data based on the digital filter data. The waveform data is compressed. The compressing includes selecting one or more points on a waveform, wherein the one or more points are above a predetermined threshold. The compressing includes determining an inflection of the selected points based on a predefined algorithm.

Abstract: Electrical currents are detected and analyzed across structural members in a structural joint, such as a fastener of a vehicle. In some aspects, printed circuit boards etched with Rogowski coil circuits are inserted proximate the structural members in the structural joint. The Rogowski coil circuits may detect an electrical current as it flows through the structural joint. An integrator may integrate a transient current to generate an output signal, such as when the vehicle is subjected to an electrical charge. The output signal may be transmitted to an Integrated Vehicle Health Management (IVHM) system for analysis. In various aspects, the IVHM system may enable recording and reporting of various aspects of the current to enable maintenance, inspection, or real time/near real time health assessment of the vehicle.

Abstract: A system and method for detecting lightning strikes on a wind turbine includes detecting and measuring a parameter that is indicative of a lightning strike, which may be current induced in a conductor as a result of the lightning strike. A current receptor may be located on a component of the wind turbine and electrically coupled to a ground conductor. A current sensor is disposed on the ground conductor and generates a primary current I(p) that is proportional to a lightning strike current flowing through the ground conductor upon a lighting strike on the receptor. A signal converter sub-system is configured to convert the primary current I(p) into a processing signal. A processing sub-system is configured to receive and use the processing signal to determine an actual lightning strike on the wind turbine.

Abstract: A lightning detection and damage estimation system for a structure is disclosed herein. The system includes a lightning receptor coupled to a lightning conductor configured to receive multiple lightning strikes and induce lightning current in a pick-up coil coupled to the lightning conductor. An integrated circuit coupled to the lightning conductor via the pick-up coil includes a non-volatile memory for successively storing one or more samples of the lightning induced current for the multiple lightning strikes. A damage estimation unit is configured to estimate a condition of the structure based on analyzing a history of stored samples of the lightning induced current of the multiple lightning strikes from the non-volatile memory.

Abstract: The present invention has an object to provide a lightning current detection sensor that has a configuration resistant to high voltage and high current in a lightning strike and has high sensitivity and high resolution. In a lightning current detection sensor 10, an insulation-coated wire 22 wound in multiple turns is collectively covered with a base tape 21 and a cover tape 23. Thus, even when the insulation-coated wire 22 is wound in multiple turns to increase sensitivity, a minute area can be detected to increase resolution. Also, with the base tape 21 and the cover tape 23 covering the insulation-coated wire 22 and also a shield portion 12 made of an insulating material and a gap 40 formed between the shield portion 12 and the coil portion 20, a sufficient shielding property is ensured and detection with high accuracy can be performed against high current and high voltage without capacitative coupling.

Abstract: A measuring device for a hard disk drive includes a first input node, a hard disk drive having a first input terminal, the first input terminal being coupled to the first input node to provide power to the hard disk drive. A first input current sampling unit is coupled between the first input node and the first input terminal of the hard disk drive to obtain a first input current Iin1. A first input voltage sampling unit is coupled to the first input terminal of the hard disk drive to obtain a first input voltage Uin1. A control unit is coupled to the first input current sampling unit and the first input voltage sampling unit to receive the first input current and the first input voltage.

Abstract: An ambient electric field detector comprising: a collection mechanism disposed to generate a current signal in response to the ambient electric field; an input current mirror operatively coupled to the collection mechanism and disposed to amplify and duplicate the current signal to generate a duplicate signal; and an odd number (i) of at least three nonlinear, over-damped, bi-stable elements coupled uni-directionally in a ring such that the ring of elements oscillates, wherein at least one of the elements has a different initial state than the other elements and each element is disposed to receive the duplicate signal.

Abstract: In the illustrated embodiment of the invention a scanning system is provided for scanning a chargeable surface for latent image detection. The chargeable surface is charged to a first potential, and a scanner probe is charged to a second potential within a predetermined potential difference from the first potential. The scanner probe is oscillated at a selected frequency and reads or measures the oscillation current that is induced from the oscillation and detects any latent images or other electrostatic distributions on the chargeable surface. A processor processes the probe measurements for determining the potential of a latent image on the chargeable surface based on the scanner probe readings.

Abstract: A grid sensor significantly reduces the complexity of a production process. The cost for installing and running the grid sensor are significantly reduced and the service life, pressure and heat resistance of the grid sensor can be significantly increased over previous grid sensors. Channels, which are wider than the diameter of the wire electrodes and have a depth of less than half the thickness of the sensor board, run outwardly from the edge of the measurement cross section in the sensor board. The channels are coated by a metal layer and the wire electrodes are inserted into the periphery of the measurement cross section. The two ends of the electrode, each in one of the opposite channels, and the electrodes are fixed in the channels by means of a conductive sealing compound. In each channel, the conductive sealing compound terminates in a planar fashion with the upper side of the sensor board, and the sensor board is clamped between two clamping plates.

Abstract: A safety interlock for use in a medical device having a control system for controlling operation of the medical device includes a central tubular portion defining a fluid passage for passing fluid through the safety interlock. An outer ring portion is adapted for mounting the safety interlock in the medical device. A spoked connector portion connects the central tubular portion to the outer ring portion so that the outer ring portion is spaced radially outwardly from the central tubular portion in opposed relation with at least a portion of the central tubular portion. The safety interlock is adapted for mounting in the medical device in a path of electromagnetic radiation from a source of electromagnetic radiation such that the central tubular portion reflects the electromagnetic radiation to a electromagnetic radiation detector when properly loaded on the medical device.

Abstract: A conductive member evaluator includes a first electrode which has contact with an outer circumferential face of a conductive member, a second electrode which is connected to the shaft center of the conductive member, a voltage applier configured to apply evaluation voltage including at least an AD component between the first electrode and the second electrode, a current value measuring device configured to measure a current value flowing between the first electrode and the second electrode when the evaluation voltage is applied, an extreme value obtaining device configured to obtain at least one extreme value of a maximum value and a minimum value in one cycle of the AD component included in the current value from the current value measured by the current value measuring device; and an evaluation device configured to evaluate the conductive member based on the extreme value obtained by the extreme value obtaining device.

Abstract: An arrangement to detect a lightning strike in a wind turbine is provided. According to the arrangement, the wind turbines contains an ozone sensor. The ozone sensor is located close to a component of the wind turbine. The component is constructed and arranged in a way that a lightning current, which results from a lightning strike into the wind turbine, is conducted through the component. The component is constructed and arranged in a way that the lightning current results in a corona generating a certain amount of ozone gas, which is detected by the ozone sensor.

Abstract: An analog input module for a programmable logic controller, wherein the analog input module has a ground potential, and includes a channel output configured at a first electrical potential, a first channel input configured at a second electrical potential where the absolute value of the second electrical potential is less than the absolute value of the first electrical potential and greater than the absolute value of the ground potential. The analog input module also includes a second channel input, and a third channel input, where the ground potential of the analog input module is the ground potential of the channel output, of the first channel input, of the second channel input and of the third channel input.

Abstract: Broadband isotropic (omnidirectional) antenna typically comprising three orthogonal small size monopole antennas protruding through the centers of three adjacent sides of the small metal cube. Each antenna has the frequency correcting network and RF amplifier. Signals from all three antennas are commutated by the RF switch (multiplexer) and the output can be applied to any RF spectrum analyzer. It is shown that if spectrum analyzer sweeps at relatively slow rate or is used in max/hold mode, the resulting display is proportional to the magnitude of the electromagnetic field vector independent of the orientation of the monopole antennas with respect to the E-field direction. Another embodiment improves the circuit accuracy in case when one dominant RF signal is present.

Abstract: This disclosure describes systems and methods for determining a voltage margin (or margin) of a serializer/deserializer (SerDes) receiver in mission mode using a SerDes receiver. This is done by time-division multiplexing a margin determination and a tap weight adaptation onto the same hardware (or software, or combination of hardware and software). In other words, some parts of a SerDes receiver (e.g., an error slicer and an adaptation module) can be used for two different tasks at different times without degrading the effectiveness or bandwidth of the receiver. Hence, the disclosed systems and methods allow a SerDes receiver to determine the SerDes margin in mission mode and without any additional hardware or circuitry on the receiver chip.

Abstract: This invention is concerned with a method for measuring the canopy rehydration pulse during the period of water application. During the rehydration process water leaks from the trunk xylem tubes into the sapwood extraxyllary region. A water content sensor in this region monitors the magnitude and timing of this leakage water thereby giving a measure of the magnitude and timing of the upward flow of water. The rehydration pulse is quantified by a sequence of measurements of sapwood water content: an initial measurement of water content just prior to water application, then measurement of water content during water application. The difference between the values obtained in the two measurements yields a measure of the leakage water in the extraxyllary region and, in turn, the magnitude and timing of the rehydration pulse. Determination of the onset and termination of the rehydration pulse is used to optimize the duration of water application.

Abstract: A system and method for detecting lightning strikes on a wind turbine includes detecting and measuring a parameter that is indicative of a lightning strike, which may be current induced in a conductor as a result of the lightning strike. A current receptor may be located on a component of the wind turbine and electrically coupled to a ground conductor. A current sensor is disposed on the ground conductor and generates a primary current I(p) that is proportional to a lightning strike current flowing through the ground conductor upon a lighting strike on the receptor. A signal converter sub-system is configured to convert the primary current I(p) into a processing signal. A processing sub-system is configured to receive and use the processing signal to determine an actual lightning strike on the wind turbine.

Abstract: Embodiments pertain to simulator circuitry, particularly to simulator circuitry configured to simulate an electric vehicle and test an electric vehicle charger (110). A test unit (210) is configured to simulate a GFI current via modulator (1623) and to simulate electric vehicle loads via switched and combined resistor loads (1800). The test unit (220) provides for reprogramming of the electric vehicle charger (110) via a pilot line (323). The test unit (220) self-confirms its usability via associating received codes (1300).

Abstract: An atomic scale electroconductivity device with electrostatic regulation includes a perturbing species having a localized electronic charge. A sensing species having an electronic conductivity is placed in proximity to the perturbing species at a distance sufficient to induce a change in the electronic conductivity associated with the localized electronic charge. Electronics are provided to measure the conductivity via the sensing species. A temporally controlled atomic scale transistor is provided by biasing a substrate to a substrate voltage with respect to ground.

Abstract: A measuring system minimizes the parasitic affects of lumped circuit elements. The system includes two or more in-situ interfaces configured to conductively link a source to an internal load and an external load. The in-situ interfaces are linked to a shunt conductor. Two or more linear and dynamic elements conductively link the in-situ interfaces in series. The dynamic elements are configured to overwhelm the parasitic self-capacitance of an input circuit coupled to at least one of the in-situ interfaces. A shield enclosing at least one of the linear and dynamic elements has a conductive surface to fields and electromagnetic interference. The shield has attenuation ratios that substantially dampen the parasitic capacitance between the linear and dynamic elements that bridge some of the in-situ interfaces.

Abstract: A safety interlock for use in a medical device having a control system for controlling operation of the medical device includes a central tubular portion defining a fluid passage for passing fluid through the safety interlock. An outer ring portion is adapted for mounting the safety interlock in the medical device. A spoked connector portion connects the central tubular portion to the outer ring portion so that the outer ring portion is spaced radially outwardly from the central tubular portion in opposed relation with at least a portion of the central tubular portion. The safety interlock is adapted for mounting in the medical device in a path of electromagnetic radiation from a source of electromagnetic radiation such that the central tubular portion reflects the electromagnetic radiation to a electromagnetic radiation detector when properly loaded on the medical device.

Abstract: An arrangement to detect a lightning strike in a wind turbine is provided. According to the arrangement, the wind turbines contains an ozone sensor. The ozone sensor is located close to a component of the wind turbine. The component is constructed and arranged in a way that a lightning current, which results from a lightning strike into the wind turbine, is conducted through the component. The component is constructed and arranged in a way that the lightning current results in a corona generating a certain amount of ozone gas, which is detected by the ozone sensor.

Abstract: Certain embodiments of the invention may include systems, methods, and apparatus for providing detecting lightning strikes. According to an example embodiment of the invention, a method for determining a lightning strike event, classification, and location is provided. The method includes receiving lightning electrical current in least one down conductor, generating voltage and polarity signals based at least in part on the received lightning electrical current, storing the generated voltage and polarity signals, and determining the lightning strike event, classification, and location based at least in part on the stored voltage and polarity signals.

Abstract: In various embodiments, an apparatus for detecting electric fields is disclosed that includes an array of non-linear elements configured into an oscillator with each coupled to one or more electric-field sensing plates. In various embodiments, an output of the array produces a frequency that varies as a function of an electric field sensed by the one or more electric-field sensing plates.

Abstract: The present invention relates to a non-contact arc detection, recognition, and warning apparatus for the detection of arcing in an electrical system. The apparatus includes an electric field detector having first and second electric field sensors adapted to sense electric fields; a magnetic field detector having a multi-axis magnetic field sensor adapted to detect a magnetic field; and a digital signal processor. The digital signal processor compares and enhances signals obtained from the electric field detector and the magnetic field detector and creates a response to alert a user of the presence of arcing.

Abstract: The present invention provides a method and system for monitoring external excitation on a surface using nanocomposite paint. The method comprises applying the nanocomposite paint on the surface, wherein the nanocomposite paint comprises a mixture of a plurality of carbon nanotubes and an epoxy resin along with a plurality of electrically conductive patterned electrodes. The electrical properties of the nanocomposite paint changes in response to the external excitation of the surface. The change in the electrical properties of the nanocomposite is measured by a measuring instrument, wherein the change in the electrical properties of the nanocomposite paint is directly proportional to the external excitation experienced by the surface.

Abstract: A stand-off sensor assembly is provided. The sensor assembly includes a plurality of electron state definers for generating resonant tunneling current in response to the electric field, wherein the electron state definers include at least one variable characteristic such that a change in the variable characteristic affects the tunneling current, and a monitor for monitoring a change in the tunneling current exiting an electron state definer based on a change in the variable characteristic of the tunneling device.

Abstract: A distributed safety monitoring system is provided with a first safety loop for connecting safety relays in series to a common power supply. The opening of any one of the safety relays can be detected by a current detector located in the safety loop. Each safety relay is part of a local safety monitoring device, which is provided with a local power supply and a test circuit, to allow local testing of the safety relay independently from the common power supply. Hence, the safety relays can be tested simultaneously.

Abstract: A system and method for performing a continuity test on a lightning conduction system of a wind turbine are disclosed. The system generally includes a testing device having a blade ring configured to be positioned around at least a portion of an outer perimeter of a rotor blade of the wind turbine. A carriage may be attached to the testing device and a cable may be attached to the carriage. The cable may generally extend between a first anchor point and a second anchor point, wherein the anchor points are spaced apart from one another such that a lightning receptor of the lightning conduction system is disposed between the anchor points. Additionally, the cable may be coupled between the anchor points such that, as the cable is displaced, the testing device is moved to a position at which an electrically conductive member of the testing device contacts the lightning receptor.

Abstract: A lightning detection system and method for detecting a lightning strike are provided. The system includes a lightning detector in a structure susceptible to a lightning strike. The lightning detector includes a data logger configured to log data indicative of a time of occurrence of the lightning strike. The system further includes memory to store data collected from a wide-area lightning detection network. The stored data includes at least one characteristic of the lightning strike. A processor may be configured to process data from the data logger relative to data collected from the wide-area lightning detection network to determine correlated data indicative of a lightning strike affecting the structure. In the event correlated data is determined, the processor may be configured to assign the characteristic of the lightning strike to the structure.

Abstract: An electrical specific resistivity probing robot is directed to automatically measuring a three-dimensional electrical specific resistivity structure of an underground shallow region by installing a plurality of probing electrodes at regular intervals along a robot-moving caterpillar to measure difference of potentials of the electrodes at a ground plane. The electrical specific resistivity probing robot includes a frame, a driving member installed under the frame, a pair of insulating caterpillars installed to both sides of a lower portion of the frame and driven by the driving member, a plurality of probing electrodes installed along track circumferences of the caterpillars at regular intervals, a slip ring electrically slip-connected to the probing electrodes one by one, and a cable electrically connected to the slip ring.

Abstract: A system, including an improved sensor, for determining toner particle uniformity is described. The sensor measures toner particle charge, typically be having the charge on the toner particle control a current flow through the channel of a thin film transistor. By measuring the charge on many toner particles, the system determines whether sufficient toner degradation has occurred that the toner should be replaced. The sensor is particularly suitable for being formed on a thin diagnostic sheet that is input through the paper path of a printing system.

Abstract: Unsafe electric energies can exist in aircraft fuel tanks as a result of static build-up or induced currents from lightning strikes. The invention provides an aircraft fuel tank including two discharge paths for the safe discharge of electricity from the tank before it reaches levels where an arc, spark or other electric discharge, able to ignite fuel in the tank, could occur. The failure of both the discharge paths would significantly increase the risk of an ignition causing electrical discharge occurring. The tank thus also includes a circuit for monitoring the integrity of each discharge path. By having at least two discharge paths, should one discharge path fail (which failure being detected by the monitoring circuit, at least one alternative discharge path exists for the safe discharge of electrical energy from the fuel tank, until the failed discharge path is repaired.

Abstract: A potential measurement apparatus for measuring a surface potential of an object of measurement detects a change in electric charge induced at a detection electrode due to electrostatic induction by changing a distance between the detection electrode and the object of measurement in accordance with a predetermined period, using a neutral distance as reference, as a signal representing a change in electric current.