459results about "Electrostatic field measurements" patented technology

The invention discloses an error correction method and device for non-intrusive voltage differential measurement, a medium and a product, and relates to the technical field of voltage measurement, and the method is applied to a scene in which a differential electric field sensor array is arranged in a set range with a measured conductor as the center. Comprising the following steps: constructing an initial correction model based on a sensor distance and a measured conductor voltage; under the actual working condition, the initial correction model is processed through a least square method, and a correction model is obtained; when non-intrusive voltage differential measurement is carried out, the current measured conductor voltage and the sensor distance are obtained, and a correction coefficient is determined by adopting the correction model; and completing error correction of non-intrusive voltage differential measurement based on the correction coefficient. According to the invention, the complexity of an inversion algorithm and the special requirement on the spatial position of the sensor can be reduced.

The invention discloses an electricity testing measuring device for power equipment. The invention relates to the field of space electric field measurement, and solves the problems of unsafety and low anti-interference capability of an existing electricity testing scheme. The electric field sensor collects the electric field intensity in a non-contact manner, and the distance sensor synchronously collects the detection distance, so that a conventional contact type electroscope does not need to contact equipment through a telescopic insulating rod. The signal processing circuit preprocesses electric field intensity information and distance information respectively to obtain effective analog signals representing the electric field to be measured, and the defect that a traditional non-contact plate electrode sensor induces stray electric fields indifferentially is overcome. Besides, the judgment control circuit judges the electrification state according to the preset electric field threshold value corresponding to the current distance analog signal instead of a single fixed threshold value of a traditional device instead of adopting a fixed threshold value, the electric field distribution characteristics of equipment with different voltage grades are adapted, manual intervention is not needed, and personal safety is guaranteed. And the occurrence rate of production accidents caused by abnormal electrification of equipment is reduced.

The invention discloses a tower grounding grid multi-frequency composite wave electric field imaging and soil environment medium diagnosis method, which comprises the following steps of: generating a composite excitation signal through superposition of a low-frequency sine wave and a high-frequency CHIRP square wave, and collecting multi-dimensional data such as voltage / current response, soil temperature and humidity, electric field intensity and the like in combination with a distributed sensor array; separating signal features by using wavelet transform and extracting impedance information of a target frequency point; a multi-grid homotopy algorithm is adopted to realize grounding grid three-dimensional resistivity distribution reconstruction, corrosion spots and abnormal areas are marked, and high-precision positioning of underground conductors is completed through UWB radar or a capacitance detector; meanwhile, based on the information entropy maximization optimization frequency band combination, the grounding grid state is comprehensively evaluated in combination with a multi-parameter fusion model. The method has the non-contact patrol capability, the unmanned aerial vehicle carries equipment to scan the grounding grid, the detection efficiency and convenience are remarkably improved, and an efficient and accurate solution is provided for guaranteeing safe operation of the power grid.

The invention discloses a power frequency phase adaptive acquisition device, and relates to the technical field of electric power signal measurement, the device acquires electric field data at a gap through an electric field sensor integrated on an edge shell, calculates electric field intensity fluctuation, and generates interference diagnosis information in combination with a preset interference determination threshold value; when the interference diagnosis information shows that effective interference exists, the electric field intensity variable quantity is calculated, a mapping model is established based on a proportionality coefficient obtained through an experiment so as to obtain zero crossing point offset, and the sampling trigger moment of a zero crossing point detection module is corrected; the clock synchronization module calculates a phase difference by taking the corrected trigger moment as a reference, dynamically adjusts a calibration frequency by combining a phase difference threshold value, and outputs a synchronized system clock signal; and the control system takes the synchronized system clock signal as a trigger signal, collects power frequency phase data according to a power frequency period, and stores the power frequency phase data to a database through a transmission unit, thereby realizing high-precision power frequency phase collection.

The invention belongs to the technical field of high-power microwave effect tests in laboratories, and relates to a built-in conformal optical fiber electric field sensor array test system and method, and the method comprises the following steps: S1, preparing before implementation; s2, quick assembly and disassembly are carried out; s3, real-time measurement and closed loop are carried out; s4, a step of result confirmation and log uploading; s5, a step of preparing a next round of experiment; the technical scheme of the invention is mainly used for carrying out internal electric field distributed measurement on a fixed test body or a slide rail supported test body in a shielding cabin, a compact range or a GTEM room and other experimental environments; the system is composed of a conformal optical fiber electric field sensor array, an optical fiber link unit, a photoelectric integration module, a self-calibration unit, an energy source and an interface, can be assembled and disassembled within 5 min, can be repeatedly used for more than 100 times, remarkably reduces the operation cost of a laboratory, and provides a core test means for a high-precision, high-efficiency and low-cost anti-missile weapon HPM effect test.

The invention discloses an application method and system of an intelligent electroscope in marketing operation, and the system employs a non-contact electric field sensing module to detect the power-on state of an electric power line, avoids manual contact measurement, reduces the risk of electric shock of personnel, carries out the filtering and feature extraction (time domain and frequency domain features) of an electric field signal through a data processing unit, and improves the detection precision. A machine learning model (such as SVM and DNN) is combined to train historical data, real electrified signals and interference signals can be effectively distinguished, and detection errors are reduced; electricity testing data remote transmission is achieved by means of a wireless communication module, task issuing, automatic result uploading and abnormal alarm are completed in combination with a marketing operation system, manual recording and feedback are not needed, the problems that remote confirmation is difficult and information transmission lags behind in a traditional mode are solved, and intelligence and high efficiency of electricity marketing operation are improved; the positioning module records the geographic position of the electricity testing point and synchronizes the geographic position to the marketing operation system, thereby facilitating operation flow tracing and task overall scheduling, and optimizing the marketing operation flow.

The invention relates to an insulating material, in particular to a nano composite insulating material, an insulated cable and an insulation defect repairing robot. The nano composite insulating material comprises core-shell particles, modified montmorillonite and crosslinked polyethylene, wherein each core-shell particle is provided with a core layer and a shell layer. The insulating layer of the insulated cable is made of the nano-composite insulating material. The insulation defect repairing robot can utilize the insulation defect repairing material to repair the crack defect of the insulation layer of the related cable. The material can automatically repair cracks under the action of an electric field and a thermal field, repeated repair for more than five times is achieved, micro defects smaller than or equal to 100 microns can be automatically repaired in the cable operation process, 90% of unplanned power failure faults are reduced, and the whole life cycle fault cost is reduced by 60%.

The invention relates to the technical field of electric field detection and early warning. The invention aims to overcome the defect of lack of an electric field detection device under the hot-line working condition of an ultra-high-voltage line in the prior art, and relates to an electric field detection device under the hot-line working condition of the ultra-high-voltage line, which is a non-contact electric field detection device and is used for detecting the electric field under the hot-line working condition of the ultra-high-voltage line in the hot-line working condition of the ultra-high-voltage line. The non-contact electric field detection device takes a microprocessor as a core control unit, and is composed of a double-spherical-shell type electric field sensor, a differential amplifier, a filter circuit, a true RMS conversion circuit, a power supply module and a man-machine interaction circuit. And deep association of data support, function collaboration and scene adaptation is carried out through the structure. The problem that traditional equipment is insufficient in stability in a severe environment is solved, continuous and stable operation of the electric field detection equipment under complex working conditions is achieved, it is ensured that reliable electric field intensity data can be continuously output, and a basic guarantee is provided for operation safety evaluation.

The invention relates to the technical field of high-voltage electrostatic parameter measurement and circuit detection and analysis, and discloses a lampblack purifier high-voltage field intensity detection circuit method based on electrical variable measurement, which comprises the following steps: acquiring a real-time discharge current and output voltage data sequence of a detected electrostatic field load; determining a dynamic electrical stiffness parameter according to the response gradient; extracting a direct current component of the current to determine a real-time leakage conductance parameter; establishing coupling characteristics of the electrical stiffness increment and the leakage conductivity change rate, and judging impedance boundary displacement when the characteristics are mismatched; calculating the virtual displacement of the surface of the polar plate by using the discrete curvature of the electrical stiffness evolution trajectory; according to the method, the field intensity dynamic compensation is realized by sensing the change of a charge migration path, and the calculation deviation caused by medium accumulation is eliminated.

The invention discloses a substation danger area judgment method and system based on electric field gradient perception, and relates to the field of safety monitoring, and the method comprises the steps: arranging an electric field sensor array in a key equipment area of a substation; performing noise reduction processing on the data of each sensor node to obtain an electric field vector set; obtaining the electric field intensity change rate of each monitoring point through a space vector differential algorithm, and generating an electric field gradient tensor; dividing the electric field gradient value, and constructing a dynamic danger level mapping rule; performing spatial interpolation through a Delaunay triangulation algorithm to generate an electric field gradient equipotential surface; constructing an electric field gradient space distribution model, and generating a dynamic danger boundary envelope body in real time; and correcting the boundary of the dangerous area through the pre-trained gradient compensation coefficient matrix and triggering a graded early warning signal. The method has the advantages that the electric field gradient change of the transformer substation is monitored in real time through the electric field sensor array and the wavelet denoising technology, the dangerous area is dynamically evaluated, and the accuracy and real-time performance of dangerous area judgment are effectively improved.

The invention discloses a landfill leakage detection method and system based on a boundary double-voltage electric field, and the method comprises the steps: building an artificial electric field which covers the whole area of a landfill along a boundary measuring line electrode at the periphery of the landfill based on the high-resistance characteristic of an impermeable film and the conductive characteristic of leachate, and collecting the boundary potential and electric field data through the high and low double-voltage artificial electric field, the method comprises the following steps: constructing a boundary survey line data pair of physical alignment through differential denoising and normalization preprocessing, adopting an encoder-decoder architecture based on 1D-CNN, fusing spatial transformation and a Focal Loss loss function, directly learning a mapping relation between a boundary survey line potential anomaly mode and an internal leakage position, and outputting a leakage probability distribution diagram of a corresponding landfill contour. The method does not need to excavate and pre-embed the landfill pile body, the positioning precision reaches + / -2m, the single detection time consumption is less than or equal to 4h, the comprehensive cost is reduced by 70%, the electrode reuse rate is greater than or equal to 90%, the method is suitable for landfill sites with various shapes and various stages, and efficient, accurate and low-cost detection of the leakage area is realized.

The invention discloses a non-intrusive sensor with an external excitation source and a voltage measurement method, and the non-intrusive sensor comprises an induction signal collection unit, an induction signal conditioning unit, and a main control unit. The main control unit is respectively connected with the induction signal conditioning unit and the cable power supply, the induction signal conditioning unit is connected with the induction signal acquisition unit, and the induction signal acquisition unit is in non-contact inductive coupling connection with a cable to be detected; the main control unit is used for injecting the specific excitation signal into an alternating current loop of a cable power supply to form a composite signal, analyzing the composite signal based on a preset excitation source amplitude parameter, and calculating the power supply voltage of the to-be-detected cable; the induction signal acquisition unit generates a corresponding induction signal by capturing electric field energy generated by a composite signal in the to-be-detected cable; the induction signal conditioning unit carries out standardization processing on the induction signal. According to the invention, the technical problems of low external excitation voltage measurement precision, low system integration and single excitation source generation mode in the prior art are solved.

The invention relates to an electric field visualization real-time monitoring system and method, belongs to the technical field of electric field visualization, and is used for solving the problems of insufficient real-time performance, large measurement interference, incomplete imaging, weak multi-user cooperation and lack of unified time reference in the prior art. The method comprises the following steps: acquiring electric field scattering data of a test body by a conformal optical fiber electric field sensor array, transmitting the electric field scattering data to an edge GPU node through a plastic optical fiber-CAN-FD link, and converting the electric field scattering data into electric field amplitude data; the edge GPU node is combined with WebGL3D texture mapping and a volume ray casting algorithm to complete volume rendering, and multi-user concurrent interaction is realized through a Web server and a browser client; and a White-Rabbit clock architecture is adopted to provide a unified time reference for the whole process. According to the method, dynamic and accurate capturing of the electric field is achieved, and the multi-user concurrent access requirement is effectively met.

The disclosure provides a wafer-level enhanced electric field sensor and a preparation method thereof, which can be applied to the technical field of electric field sensors. The wafer-level enhanced electric field sensor and the preparation method thereof comprise: a substrate for supporting an electric field sensitive structure, the surface of the substrate being provided with an anchor point; the electric field sensitive structure is arranged on the substrate and is used for sensing a to-be-measured electric field, wherein the electric field sensitive structure comprises any one of the following: a charge sensing type structure, an electrostatic force type structure, a piezoelectric type structure, a piezoresistive type structure and a guided charge type structure; a field enhancement cover plate is located above the electric field sensitive structure and is used for concentrating the to-be-measured electric field so as to enhance the electric field intensity acting on the electric field sensitive structure; and an insulating support structure layer is arranged at the edge of the substrate and is used for connecting the field enhancement cover plate and the substrate.

The invention provides a nonlinear high-order vibration mode modulation method of an MEMS electric field sensor, and relates to the technical field of electric field sensors. The method comprises the following steps: constructing a three-dimensional simulation model of a resonant structure of the MEMS electric field sensor, and extracting vibration mode characteristics of a multi-order mode; according to the vibration mode characteristics of each order mode, the structure and the arrangement mode of a driving electrode and an induction electrode in the electric field sensor are optimized; applying an alternating current and direct current combined driving voltage matched with the target high-order mode to the driving electrode, so that the electric field sensor works in a Duffing nonlinear state of the target high-order mode; sensing signals are collected and processed, performance indexes including sensitivity, background noise and resolution are calculated, and the performance of the electric field sensor is evaluated. According to the invention, the electric field sensor is driven to work in a high-order mode and enters a Duffing nonlinear response area, so that high-sensitivity and high-resolution detection of an external electric field is realized, and noise is effectively suppressed.

The invention discloses a sensing unit structure of a piezoelectric-piezoresistive coupling type electric field sensor and application, the sensing unit structure comprises a substrate, the substrate is provided with a cantilever beam structure, a piezoelectric crystal block is bonded between the lower surface of the cantilever beam structure and the upper surface of the substrate, and the upper surface of the cantilever beam structure is provided with a Wheatstone full-bridge structure; when the piezoelectric crystal block is subjected to the action of an electric field, the piezoelectric crystal block deforms in the Z-axis direction under the action of an inverse piezoelectric effect, so that the cantilever beam structure deforms; in the Wheatstone full-bridge structure, the resistors arranged at the position with the maximum stress difference value are stressed to deform, the stress directions of the resistors are opposite, and the resistance values of the resistors are changed oppositely; compared with the sensing unit structures of electro-optical and mechanical electric field sensors commonly used at present, the sensing unit structure has the advantages of larger measuring range, smaller volume, lower power consumption and easiness in mass production.

The invention relates to the technical field of electronic measurement, and provides a small electric field sensor which comprises a signal receiving module, a cascade gain module, a main control module, a gain control module and a filtering module. The signal receiving module is composed of a differential transmission interface and a double-diode. The cascade gain module comprises an instrument operational amplifier and two in-phase operational amplifiers SGM8061U8 which are connected in series; the main control module comprises an interface unit, a frequency measurement unit and a control unit; the gain control module is composed of an SGM4511 four-way analog switch; and the filtering module is composed of two groups of three-stage filters. The method is suitable for signal detection in various scenes such as aerospace, submarine and industrial equipment monitoring. The signal acquisition stability and response speed of the system in a complex electromagnetic environment can be improved.

The invention discloses a thunderstorm cloud electric field prediction method, device and equipment based on a deep learning algorithm, and relates to the technical field of thunderstorm cloud electric field prediction. The method comprises the following steps: firstly, acquiring a target convection parameter group of a region of interest, and acquiring historical observation data of each convection parameter in the target convection parameter group and historical observation data of an electric field in a thunderstorm cloud; constructing a convection parameter prediction model and a thunderstorm cloud internal electric field inversion model based on historical observation data; integrating the two models to obtain a thunderstorm cloud internal electric field prediction model corresponding to each convection parameter set; and performing thunderstorm cloud internal electric field prediction on the region of interest according to the thunderstorm cloud internal electric field prediction model corresponding to each convection parameter set. According to the application, convection parameter prediction and in-cloud electric field inversion are fused, and prediction of the thunderstorm in-cloud electric field can be realized by using observable convection parameters.

Method for characterizing an anechoic chamber and associated devices. The present invention relates to a method for characterizing an anechoic chamber (10), the method comprising a step of: - for several measurement points spatially arranged according to a circle, acquisition of a signal), - conversion of the acquired signals into components, each component being the value of a respective order of the decomposition of the sum of the acquired signals into phase modes, - filtering of each component by application of a compensation filter eliminating the frequency dependence, - estimation of the amplitude and direction of arrival of parasitic scatterers by solving a system of equations according to which each filtered component is equal to a sum of contributions of the parasitic scatterers, each depending on the amplitude and direction of arrival of the scatterer,and - determination of the characterization parameter from the estimated amplitudes and directions of arrival. Figure for the abbreviation: figure 1,

A battery management apparatus according to an embodiment of the present disclosure includes: a curve acquisition unit configured to acquire a differential curve representing a correspondence relationship between a voltage of a battery and a differential capacity; and a control unit configured to determine a first point as a starting point of a preset target voltage section of the differential curve, a second point having the highest differential capacity, and a third point having the lowest differential capacity in a voltage section having a voltage higher than or equal to that of the second point in the target voltage section, and diagnosing the state of the battery according to the differential capacities of the first point, the second point, and the third point.

According to the vector coupling electric field detection device and method for landfill geomembrane damage, an alternating current electric field emission mechanism is adopted, a carried electric field movement detection mechanism adopts multiple sets of electric field detection electrodes to achieve multidirectional potential vector signal detection, and potential data in the X direction and the Y direction of a detection position are synchronously collected; generating a three-dimensional potential field atlas and a potential contour map in a landfill plane range through an inverse distance weighted interpolation algorithm, and visually presenting an abnormal electric field region corresponding to a damage point; a built-in high-precision RTK position indicator binds potential data of each detection point position with coordinates of the detection point positions in real time, centimeter-level leakage holes are accurately identified, high-sensitivity detection, strong anti-interference detection and accurate space positioning of landfill geomembrane damage points are achieved, the reliability and practicability of geomembrane damage detection are comprehensively improved, and the detection accuracy is improved. And reliable data support is provided for rapid positioning and repairing of landfill operation and maintenance.

An apparatus is provided. The apparatus includes a laser generation device configured to emit a laser signal to a semiconductor fabrication component. The apparatus includes a reflection detection device configured to receive a reflection signal comprising light, of the laser signal, reflected by a surface of the semiconductor fabrication component. The reflection detection device includes an optical filter. The optical filter is configured to block light, of the reflection signal, that has a wavelength outside a defined range of wavelengths. The optical filter is configured to provide filtered light, from the reflection signal, that has a wavelength within the defined range of wavelengths. The reflection detection device includes a light sensor configured to generate an electrical signal based upon the filtered light. The apparatus includes a computer configured to determine, based upon the electrical signal, measures of electrostatic field strength at the surface of the semiconductor fabrication component.

A system for automatically locking a control laser in a Rydberg atomic sensor may comprise an atomic vapor cell, a probe laser configured to excite the atoms in the atomic vapor cell to an intermediate energy state, and a control laser configured to excite the one or more atoms in the atomic vapor cell from the intermediate energy state to a higher energy state. The light generated by the control laser may be dithered at a pre-determined frequency. The system further comprises a photodiode configured to convert light received from the vapor cell into an electrical signal, a lock-in amplifier configured to generate an error signal based on the electrical signal received from the photo diode and a received reference oscillation frequency, and a servo configured to receive the generated error signal from the lock-in amplifier and adjust a frequency of the control laser based on the received error signal.

The invention discloses an intelligent electrostatic monitoring system and method based on state self-sensing, and belongs to the technical field of industrial safety monitoring, and the system comprises a pipeline, a Faraday cup sampling mechanism driven by a cylinder, a multi-sensor module and an intelligent control unit. The core of the method is that air pressure and displacement signals of an air cylinder are collected in real time and compared with a pre-stored reference model, the motion state of the air cylinder is intelligently diagnosed, a hierarchical fault-tolerant control strategy is triggered according to a diagnosis result, and self-recovery or shutdown protection is achieved. And the sampling frequency can be adaptively adjusted. The Faraday cup adopts a double-layer shielding structure with height difference and a connector with a round top and a square bottom so as to resist interference; and a top-speed opening and closing mechanism is combined with a multiple flexible anti-blocking sealing structure, so that the problems of mechanical blocking and sealing are effectively solved. According to the invention, the conversion from passive maintenance to predictive maintenance is realized, and the reliability, availability and intelligent level of monitoring equipment in a severe industrial environment are greatly improved.

The invention relates to the technical field of electric field sensors, in particular to an electric field sensor gain increasing method based on nitride quantum dots. The method comprises the following steps: firstly, constructing a nitride and graphene heterojunction model by utilizing a first principle, calculating quantum capacitance, and screening out optimal quality structure configuration; preparing a sensor according to the configuration and the initial process parameters, and obtaining the actual measurement sensitivity in the simulated electric field; further constructing an optimization model taking the quantum dot size and the dielectric layer thickness as input and the sensitivity as a target, calculating a parameter gradient by utilizing a gradient ascending method, and outputting a correction value; and finally, carrying out closed-loop iteration of preparation, testing, calculation and adjustment until the objective function is converged, and outputting final process parameters. According to the invention, collaborative optimization of microcosmic electronic structure screening and macroscopic process parameters is realized, and the detection sensitivity and the signal-to-noise ratio of the electric field sensor are remarkably improved.

A method of measuring a delay time of a propagation of a signal in a line in a circuit structure, the method comprises irradiating the line by pulses of a charged particle beam, wherein a pulse repetition frequency of the pulses of the charged particle beam is varied. The method further comprises measuring, for each of the pulse repetition frequencies, a secondary charged particle emission responsive to the irradiating the line by the pulses of the charged particle beam at the respective pulse repetition frequency, and deriving the delay time of the line based on the secondary charged particle emission responsive to the varying of the pulse repetition frequency.

The application provides a sensor-based plastic wrapping film anti-static performance detection method and system, and relates to the technical field of anti-static performance detection. The method comprises the following steps: receiving original static signals collected by a plurality of static induction units arranged on a production path of a plastic wrapping film, the static induction units being used for independently monitoring a unit area on the surface of the film body; performing relative comparison between the original static signals and time trend analysis to obtain analysis results; identifying a local high signal mode meeting a preset condition on the surface of the film body according to the analysis results; determining a spatial position and a static strength at which static aggregation occurs on the surface of the film body according to the identified local high signal mode; and issuing a warning signal according to the spatial position and the static strength. The application can realize timely and accurate identification of the anti-static performance of the plastic wrapping film, thereby effectively preventing static discharge damage to sensitive electronic elements packaged in the finished film roll.

The invention provides a piezoelectric excitation out-of-phase vibration micro electric field sensitive structure, a sensor and a detection method. The sensor comprises the piezoelectric excitation out-of-phase vibration micro electric field sensitive structure, a substrate (6), an elastic beam (7), a piezoelectric driving unit (1) and a piezoelectric feedback unit (4), the piezoelectric excitation out-of-phase vibration micro electric field sensitive structure comprises an out-of-phase vibration unit (2) and a differential sensing unit (3). Induction electrodes of the differential induction units (3) are arranged on the substrate (6); the elastic beam (7) is connected with the substrate (6) and the out-phase vibration unit (2); the piezoelectric feedback unit (4) and the piezoelectric driving unit (1) at least comprise a piezoelectric material layer and two electrode layers, one end of the piezoelectric feedback unit (4) is fixed on the substrate (6), and the other end of the piezoelectric feedback unit (4) is connected with the elastic beam (7). According to the invention, differential detection can be realized, and crosstalk and environment common-mode noise in an alternating-current excitation signal can be effectively suppressed.

A vegetation flame condition direct current gap multi-physical field coupling simulation method, determines the physical quantity required for simulation of charged particle motion, distribution and electric field distribution in the air gap under the condition of applying direct current voltage under the condition of typical vegetation flame, the connection between each physical field; determine the control equation of each physical field; determine the simulation method of multi-physical field coupling; determine the chemical reaction equation corresponding to the vegetation and the pyrolysis material coefficient; measure the vegetation flame temperature distribution and leakage current data by combustion test; compare the simulation obtained flame temperature distribution and leakage current with the test obtained temperature distribution and leakage current data, determine the vegetation pyrolysis reaction equation and chemical reaction rate parameter; simulation calculation obtains the charged particle concentration distribution characteristics and the space electric field distribution characteristics affected by the charged particles generated by the flame combustion. The present application can obtain the charged particle motion, distribution characteristics and electric field distortion of the direct current gap under the condition of typical vegetation flame.

A device for monitoring spacecraft electric potential includes a first conductor configured to be in electrical communication with a conductive structure of a spacecraft, a second conductor capacitively coupled to the first conductor, a switch connected to the first conductor and the second conductor such that closure of the switch electrically ties the first conductor to the second conductor, and a monitoring circuit in electrical communication with the second conductor, the monitoring circuit being configured to detect an electric potential of the second conductor relative to the first conductor, the detected electric potential being indicative of a change in electric potential of the first conductor relative to the second conductor since an opening of the switch.