134results about "Current density measurements" patented technology

The invention discloses an apparatus for measuring the ferroelectric hysteresis of ferroelectric materials which is based on a current measurement circuit, as well as a measurement method thereof. The invention inputs a simulated output signal generated by a computer processing unit into a high voltage amplifier through a signal source and a data acquisition board, thus giving excitation voltage to a sample being tested, and then through a sampling resistance R0, sampled current signal is input into a signal regulating module through an operational amplifier, and then the sampled current signal is transmitted back into the computer processing unit through the data acquisition board. By separating the current signal acquired from the measurement into three parts as linear polarization, non-linear polarization and electric loss, the measurement system is provided with not only the function of measuring the P-E relationship, but also the function of acquiring the relationship between the real spontaneous polarization and induced polarization of the dielectric substance being tested and the field intensity. Furthermore, by superimposing actuating signal of a small alternative electric field to a bias electric field with constant intensity and synchronously collecting the corresponding change information of the polarization intensity of the sample being tested, then the reversible permittivity can be acquired.

A transmitter that is electrically connected to a circuit and an associated receiver is used to identify an element of that circuit in the presence of other circuits. This may be used in AC or DC systems that are powered or not to identify or trace circuit elements such as lines, junctions, switches, fuses, or breakers. One version that identifies the circuit breaker of the circuit connected to the transmitter in a powered AC distribution system.

The invention belongs to the field of fuel cells, mainly relates to the field of the internal current measurement of the fuel cells, and discloses a fuel cell current density measurement flow field plate. The fuel cell current density measurement flow field plate comprises a PCB board (1); gas flow channels (2) are engraved on the PCB board (1); a plurality of mutually independent metal plating layer areas (4) are arranged on ribs (3) among the gas flow channels (2); connecting points (5) are arranged on the metal plating layer areas (4); a guide wire (6) is arranged on the back surface of the PCB board (1); one end of the guide wire (6) is electrically connected with one metal plating layer area (4) through the connecting point (5), and the other end of the guide wire (6) is converged on a terminal block (9) through a resistor (7). The use of flow field plate for the measurement of the local current of the fuel cell can allow the regional division to be more detailed and realize the measurement of the two-dimensional local current measurement, the structure is simple, the use is convenient, and the processing cost is low.

The invention relates to a device and a method for measuring voltaic arc pressure distribution and current density distribution, belonging to the technical field of voltaic arc testing. The device comprises a motor, a positioning frame, a guide rail fixed on the positioning frame, a sliding element mounted on the guide rail, a welding torch position regulating mechanism arranged at the lower end of the sliding element, a flat table surface arranged below the positioning frame, a container positioned on the flat table surface, anode plates arranged in the container, and a weighting sensor. During the measurement, the motor drives a guide screw to rotate so as to further drive a welding torch to move along a direction vertical to an insulating material. The values of voltaic arc force and voltaic arc current which are applied on the two anode plates are collected. Then, a mathematic model, which is about the value of the voltaic arc force and circle domain pressure distribution of the voltaic arc and about the value of the voltaic arc current and circle domain current density distribution of the voltaic arc, is established. Solving is carried out next. Then, curves about the circle domain pressure distribution and the circle domain current density distribution of the voltaic arc can be drawn. The device and the method realize the simultaneous measurement of the microcosmic voltaic arc pressure distribution and the microcosmic voltaic arc current density distribution. In addition, the device has a simple production process, and the testing steps are simple.

The invention discloses a partition test system of the cold start current density and temperature of a fuel cell. A fuel cell system comprises a fuel cell, a thermocouple, an ice bath, an air intake system module, a high and low temperature alternating box, a cooling tube, a data acquisition module, a data processing module, and a load. The test method comprises the steps that: a current density test board is placed at an anode; both the cathode flow field plate and the cathode end plate have jacks, and the thermocouple is placed in the jack; the ice bath provides cold junction compensation for the thermocouple; the temperature in the high and low temperature alternating box is set to be the ambient temperature of the cold start; the intake system module supplies the fuel cell with oxidantand fuel and is connected to the load to make it work normally; the data acquisition module collects the voltage of the sampling resistor and the thermoelectric potential of the thermocouple. The data processing module converts the collected signal into a current density distribution map and a temperature distribution map at each moment of the fuel cell. Compared with the prior art, the inventionhas the advantages of low manufacturing cost, accurate measurement, simple structure and the like.

The present invention relates to an apparatus and method for measuring a current density in a conductive material. The apparatus and method use an algorithm and an extension to the Fourier transform approach that allows transport currents to be treated accurately. Due to its speed, the resulting algorithm is ideally suited for high-resolution and high-throughput magnetic imaging of superconducting tape in real time.

The invention belongs to the field of testing of high temperature superconductor material performance, and particularly relates to a testing system and method for the critical current density of a high temperature superconductor film material. The system is composed of a computer, a nano-volt meter, a programmable direct-current power source and a probe station. The sample is fixed to the probe table and placed inside liquefied nitrogen, the computer controls the programmable direct-current power source to provide a current signal, the measurement value of the nano-volt meter and the output value of the programmable direct-current power source are recorded in real time, and therefore data recording and drawing are automatically completed. The testing system and method have the advantages that large-area samples can be rapidly measured in a multi-point mode and do not need to be taken out of the liquefied nitrogen any more when different micro-bridges are tested, a wire for connecting the nano-volt meter with the current source on a testing board is changed to different round hole base female headers on the testing board, namely different testing points, and therefore testing efficiency is greatly improved.

The invention provides a 800kV extra-high voltage direct-current non-contact multichannel distance measurement type electroscope comprising a signal amplification module, a signal processing module, an alarming module, an analog-to-digital conversion and data processing module and an LCD (liquid crystal display) display module, wherein the signal processing module comprises a rectification module, a filtering module, a signal acquisition module, a comparing control module and a distance measurement module, and the signal acquisition module comprises a stator and a rotor. The electricity testing value of the electroscope is the electric field value of the on-site working position, which effectively broadens the use range of the electroscope and improves the accuracy of the electroscope. The electroscope tests electricity by taking a distance value of a working position and a lead to be detected and a field intensity value correspondingly obtained according to the field intensity curve and the variation trend of a space electric field as alarming threshold values, and whether the lead to be detected is charged or not is reflected according to acoustic and light signals of alarming, thereby effectively eliminating the interference of adjacent charged equipment and solving the problems that the repeatability of an electricity testing result is poor and the accuracy is low because of the interference of the charged body of adjacent equipment to be detected on the space field intensity.

The invention relates to a system for mensurating the density of an ion current on the ground of an alternating current / direct current parallel electric transmission line and a mensuration method thereof and belongs to the technical field of electromagnetic environment of a high-tension transmission line. The system mainly comprises three parts of an ion current plate, an oscillograph and a computer stored with an ion current density analyzing program, which are connected sequentially, The method comprises the following steps: calibration data of the ion current plat is read; sampling frequency of an oscillograph is arranged; frequency spectrum is carried out on sampling data; peak value frequency is searched; direct current component is extracted; the density of a direct current composition of the ion current is calculated and is subjected to harmonic analysis; the density of an alternating current composition of the ion current is calculated; and the frequency spectrum of the density of the ion current is stored. The system for mensurating the density of the ion current on the ground of the alternating current / direct current parallel electric transmission line is successfully used to mensurate the component of the direct current component and the alternating current component of the ion current on the ground of the alternating current / direct current electric transmission line.

The invention discloses a split conductor ion flow space distribution measuring method and device in the technical field of high-pressure gas discharge measurement. The device comprises a metal bracket, a cylindrical corona cage, a shielding cable, a signal acquisition card, a computer, a first hanging disc, a second hanging disc, a first composite insulator, a second composite insulator, a first tightener, a second tightener, an insulating screw, a Wilson plate, a sampling resistor and an earth wire. Through the method and the device, measurement of an ion flow distribution condition around adjacent split conductors is realized, and a verification means is provided for theoretical research of ground electric field effect, corona loss and the like of split conductor corona discharge.

The invention relates to a differential measurement method and device for arc current density. An electrical arc performs periodical scanning on a current sensor, an upper reception copperplate is installed on the current sensor, a fine seam is processed at the centre of the upper reception copperplate, the scanning direction of the electric arc in each scanning process is parallel to the direction of the fine seam, a current signal through the fine seam is received and exported by the current sensor to be used for collection and storage. According to the differential measurement method provided by the invention, the fine seam is adopted to replace two parallel anodes in the original anode split method so as to improve the measurement accuracy in the scanning direction and effectively prevent defects such as detection omission or sudden change arising in the moving process of the electric arc between the two anodes. The differential measurement method provided by the invention does not need to make hypothesis on shapes of the electric arc spots, so that the problem of the difference between sizes of the electric arc spots in static state and dynamic state can be solved, and the non-circular electric arc current density distribution can be measured accurately.

The invention discloses a system for measuring and analyzing parameters of a surface property of a material based on a dynamic method. The system comprises a sample processing system and a measuring system; a to-be-measured material is processed with an electrolyte solution; the activity of to-be-measured liquid after reacting is measured at a preset time interval; and a dynamic data processor and a surface property calculating module in the measuring system are used for processing the to-be-measured liquid material, thereby obtaining the parameters of the surface property of the to-be-measured liquid material. An ion exchange dynamic method is used for overcoming the defects of long reaction balancing time, difficulty in confirming balance and difficulty in realizing accurate calibration of an m value during a measuring process; dynamic data acquired within a short period of time can be used for accurate forecast so as to overcome the problems of long balancing time and difficulty in confirming balance; only two parameters, namely intercept and gradient in a linear regression equation obtained through the dynamic data, are used for calculating five parameters of the surface property of the material; and the total amount of the surface charges can be directly measured.

A fuel cell system includes a fuel cell. A current density measuring apparatus is provided on a cathode side of the fuel cell. The current density measuring apparatus includes a plurality of Hall elements provided at positions corresponding to measuring positions in an electrode surface. Each of the Hall element is attached to a ferrite core fitted to a pole of a sensor mounting plate. The ferrite core and the Hall element attached to the pole make up a current sensor.

The invention provides a general method for measuring material surface property parameters. The method can measure the surface electric potential of different types of materials under different conditions accurately. The method comprises the following steps: performing saturation treatment on the material surface to be determined; mixing the saturated material which is subjected to the saturation treatment and is to be determined with an indicating electrolyte solution; measuring equilibrium concentration values of cations and hydrogen ions in indicating electrolyte of the body solution of the mixture; calculating the material surface electric potential according to the equilibrium concentration values of the cations in the indicating electrolyte; in a further technical proposal, calculating material specific surface area and surface charge density according to the material surface potential, calculating material surface electric field intensity according to the material surface charge density, and calculating total material surface charge amount according to the surface charge density and the specific surface area. The method is obtained in the relevant technology field for the first time, which can be applied widely for measuring the surface property parameters of materials with different charge types and under different conditions, and can realize combined measurement.

The invention discloses a barrel plating current intensity real-time online testing device, which comprises a data acquisition and transmission module and a transducer module, wherein the data acquisition and transmission module consists a replaceable probe, an insulating protective sleeve, a switching device and a wire; the transducer module realizes feeble current to voltage signal conversion and nonlinear compensation, displays the detected current intensity, converts an acquired current signal to a 0 to 5 volt control voltage and outputs the 0 to 5 volt control voltage. The data acquisition part of the device can be placed in a barrel to be plated with a workpiece, so the concentration of plating liquid in the barrel and the actual conditions of a workpiece plating current during temperature change can be reflected, and under a condition of a known area of the replaceable probe, the current intensity of a workpiece in a barrel plating state can be acquired in real time according to the acquisition of the plating current of the probe. After the output of a power supply is regulated by using the output signal of the device, the constant current intensity control can be realized, so the problem of uneven plating thickness caused by incorrect calculation of the surface area of the workpiece is solved.

The invention relates to a method for testing current distribution uniformity inside a single voltage-dependent resistor valve block within a wide temperature range and belongs to the technical field of electrical engineering material. The method comprises steps of: preparing micro silver electrodes on the top surface and the bottom surface of a zinc oxide voltage-dependent resistor valve block by using photoetching and sputtering; enabling the bottom surface of the zinc oxide voltage-dependent resistor valve block to adhere to a thin lead plate, uniformly dividing the top surface of the zinc oxide voltage-dependent resistor valve block into a plurality of units with equal areas, and enabling microprobes to be in contact with the silver electrodes respectively; applying voltage between the thin lead plate in contact with the bottom surface and the microprobes or a thin lead plate in contact with the top surface, measuring corresponding current to obtain a volt-ampere characteristic curve using current density as a abscissa and electric field intensity as a ordinate, and selecting a corresponding current density value from the volt-ampere characteristic curve to solve the current ununiformity of the zinc oxide voltage-dependent resistor valve block. In a measuring process, the temperature of environment is continuously and accurately adjustable. The method is capable of effectively evaluating the uniformity of the internal structure and the performance of the zinc oxide voltage-dependent resistor valve block at specific temperature in order to test and research an influence of current distribution uniformity on the operating characteristic of zinc oxide.

A method for detecting cathode protection state of submerged pipeline by noncontacting means includes setting state of submerged pipeline as per influence factor possible parameter scope of cathode protection electric field, using boundary element manner to make analog test and setting up cathode protection electric field-influence factor databank, inverting and confirming an aging state of surface protective layer on said pipeline as well as obtaining protective potential and protective current density distribution at surface of said pipeline by utilizing data collection system to obtain electric field distribution near said pipeline and utilizing prepared databank.

The invention relate to a metallic surface passive film carrier density detection method, which comprises the following specific operational steps of taking a metal rod to be measured as a test electrode, dipping the test electrode in the electrolyte solution, taking a saturated calomel electrode as an auxiliary electrode, taking a platinum electrode as a reference electrode, and measuring the relation between the applied voltage U and the capacitance Csc of the metallic surface passive film electrode system; obtaining a Mott-Schottky graph of relation; then according to Mott-Schottky relation, extrapolating the Mott-Schottky graph of relation to the intersection point of electric potential shafts to work out a flat belt potential Ufb and simultaneously work out the metallic surface passive film carrier density according to a slope coefficient. The method which introduces the prior solid state physical band theory into the metallic anti-corrosion performance inspection and analysis field is capable of not only disclosing the cause for the reduction of anti-corrosion capability in the metallic surface passive film invalidation process substantially and microscopically-the increase of the carrier density, but also quantizing the metallic surface passive film anticorrosion performance through the simple mode of electrochemically measuring the carrier which is a physical quantity varying with the corrosion time and invalidation degree, thereby enabling the metallic anticorrosion performance and the passive film invalidation degree to be monitored in a better way and providing an effective method for metallic anticorrosion performance prediction.

The invention discloses a system for analyzing material surface property parameters. The system can determine surface electric potential of materials accurately. A determining system comprises a sample processing device and a detection system, wherein the sample processing device comprises a sample accommodation device which is used for accommodating the determined materials and liquid, is also provided with a liquid inlet pipe and a liquid outlet pipe which are communicated with the sample accommodation device, wherein the liquid outlet pipe is connected with a constant flow pump, and the sample accommodation device is also provided with a stirring device; the detection system comprises an ionic activity detecting device, an ionic activity operating module and a surface parameter operating module, and the surface parameter operating module is used for receiving the ionic activity operated by the ionic activity operating module so as to work out the surface potential of the determined materials; and in a further technical proposal, total surface charge quantity, surface charge density, surface electric field intensity and specific surface area of the determined materials can be analyzed sequentially so as to realize the combined analysis of the material surface property parameter.

The invention discloses a method for monitoring organic coating material carrier density. The invention includes the following steps: measure electrode base material is stainless steel stick which is sealed with epoxy resin, after the working surface is polished, cleaned and dried, the working surface is painted with organic coating material, the thickness of the painted film is controlled at 25 microns plus or minus 2 microns, and the working surface is constant temperature dried at 35 DEG C, then the membrane coated electrode is obtained; the membrane coated electrode is dipped in 5% sodium salt solution at room temperature, the saturated calomel is used as the assistant electrode, the platinum electrode is the reference electrode, the membrane coated electrode potential U and the capacitance Csc are measured; the relationship curve between the Csc-2 and U is drawn, and the Mott-Schottky relation schema is obtained; according to the Mott-Schottky relational expression, the Mott-Schottky relation schema is extrapolated to the crossing point of the potential axis, then the flat-band potential Ufb is obtained, at the same time the space charge density ND is calculated by slope, which is the carrier density.

The invention provides a method for measuring the surface charge density of materials based on a conductive point of a scanning probe microscope, which comprises: a) scanning the surface appearance of a sample to be measured; b) measuring the change of a phase angle difference delta theta between actuating and alternating signals for driving the point to oscillate and actual oscillator signals of the point and a corresponding point bias Vt; c) according to a relation of the delta theta and the Vt, fitting the delta theta and the Vt obtained in step b) to obtain an index; and d) according to the index obtained in step c), searching the surface charge density corresponding to the index in a calibration curve based on the relation of the delta theta and the Vt, wherein the calibration curve is a relation curve of the surface charge density delta s of a standard sample and a coefficient a1. The method overcomes the difficulty of establishing a simple model for a geometrical shape of the point in the prior art, does not need considering the concrete geometrical shape of the point, makes the measurement simple and the operation easy, and has important significance for researching functions of nanodevices and nanostructures.

The invention provides a current density detection composite board. The current density detection composite board comprises a detection board and a flow field board, wherein the detection board comprises a board body, a detection unit, a first insulating part and a circuit board or a first wire; the detection unit comprises two conductive sheets which are arranged at intervals, and standard resistors of which the two ends are connected to the two conductive sheets in a one-to-one correspondence manner; one side of the flow field board is connected with one side of the board body in a fitting manner and is conducted with one conductive sheet; and a runner is formed in the other side of the flow field board. An online detection apparatus for the current density in a battery comprises the current density detection composite board. According to the current density detection composite board provided by the invention, one detection board can be matched with different flow field boards, so that the purpose of performing current density detection on bipolar plates, anode plates and cathode plates with different designs and any position in an electric pile can be achieved; the current density detection composite board has very high interchangeability; and meanwhile, a gas isolation function is not needed, and the runner does not need to be processed on the conductive sheets of the detection unit, so that the manufacturing difficulty of the detection board is lowered.

The invention provides a clearance-adjustable Faraday probe, and belongs to the field of electric propeller plasma measurement equipment. The clearance-adjustable Faraday probe comprises a collector,a first insulator, an adjustable clearance insulator, a protection ring and an adjusting bolt. The collector comprises a disc collection surface and a conductive rod which is connected with the collection surface. The first insulator sleeves the conductive rod. The protection ring is connected with the conductive rod. The outer edge of the collection surface and the internal wall surface of the protection ring have clearance. The adjustable clearance insulator sleeves outside the collector and the first insulator. The adjusting bolt and the adjustable clearance insulator are connected in a threaded way. The adjustable clearance insulator can be adjusted to stretch in or out of the clearance between the outer edge of the collection surface and the internal wall surface of the protection ring by rotating the adjusting bolt so that the Faraday probe is enabled to have two working conditions of common and clearance filling, the working condition is adjustable and thus the clearance error can be analyzed under the same dimension parameter.

The invention discloses a transversely-arranged high-current electron beam cross section three-dimensional scanning measurement system which comprises a measurement working area cavity and a Faraday cylinder sensor system. A high-vacuum movement mechanism is arranged inside the measurement working area cavity and comprises a high-vacuum three-dimensional mobile platform and a high-vacuum stepping motor. The Faraday cylinder sensor system comprises a Faraday cylinder sensor formed by an outer Faraday cylinder and an inner Faraday cylinder. A Faraday cylinder sensor support rod is fixed on the high-vacuum movement mechanism and can be moved and positioned in three directions through driving of the high-vacuum movement mechanism. The transversely-arranged high-current electron beam cross section three-dimensional scanning measurement system is small in size, can be longitudinally used separately, can serve as a part transversely arranged and connected into a large transverse high-current electron beam analysis meter to be used and can measure the whole-course transmission characteristics of a high-current electron beam under focusing of an electromagnetic field. In addition, the transversely-arranged high-current electron beam cross section three-dimensional scanning measurement system can measure the electronic optical performance of the high-current electron beam with current magnitude ranging from hundreds of volts to about hundred thousands of volts and meanwhile can further provide a beneficial calibration reference method for other quick high-voltage high-current electron beam measurement methods, such as an X-ray braking radiation method.

A method for providing a current density set-point for a fuel cell stack in response to a power request from the stack where the set-point is determined based on system parameters that identify the life and degradation of the stack. The method includes dividing a current density range of the fuel cell stack into a predetermined number of sample regions, and selecting the sample regions in order from low to high during the current set-point analysis. The method calculates an average cell voltage for the current density of the selected sample region, and stack power from the average cell voltage. The method then determines whether a power request signal is less than the stack power for the selected sample region and greater than the calculated power for the previous sample region, and if so, calculates the current density set-point at the requested power based on these values.

Optical Hall Effect (OHE) method for evaluating such as free charge carrier effective mass, concentration, mobility and free charge carrier type in a sample utilizing a permanent magnet at room temperature.

The invention discloses a method for monitoring corrosion of buried steel pipelines, comprising the following steps: embedding an inductive charge generating unit (10) in soil above a pipeline to be monitored so as to enable the inductive charge generating unit (10) to be in the same electromagnetic field environment with the pipeline so as to generate inductive charge; accumulating inductive charge generated by the inductive charge generating unit (10) repeatedly through an inductive charge accumulating unit (20); generating current by a current generating unit (30) by using the accumulated inductive charge of the inductive charge accumulating unit (20); processing the current generated by the current generating unit (30) in real time through a processing unit (40) so as to generate current density and find out the maximum instantaneous current density; and displaying the maximum instantaneous current density obtained by the processing unit (40) through a display unit (50). The invention also discloses a device for monitoring corrosion of the buried steel pipelines.

The invention provides an online detection device for internal current distribution of a fuel cell. The online detection device comprises a double-sided partition acquisition board, a signal processing module and an upper computer, wherein the double-sided partition acquisition board is arranged between any two adjacent fuel cell units and consists of a plurality of acquisition units, and each acquisition unit includes a top copper-clad gold-plated subarea, a top PCB insulating material layer, a top wiring layer, a middle PCB insulating material layer, a bottom wiring layer, a bottom PCB insulating material layer and a bottom copper-clad gold-plated subarea; the middle PCB insulating material layer is provided with a hollow area, and is internally filled with sampling resistors which are connected with metallized via holes in the middle of the top copper-clad gold-plated subarea and the bottom copper-clad gold-plated subarea; and the signal processing module performs signal processingon a potential difference between the two ends of the sampling resistor acquired by the top wiring layer and the bottom wiring layer, and displays and analyzes the potential difference in real time. The online detection device can detect the current density distribution condition of any position in a galvanic pile.

The invention discloses a Faraday probe, relates to the technical field of aerospace instruments, and aims at solving the technical problems of low measurement accuracy of the present Faraday probe. The Faraday probe comprises a Faraday probe body. The Faraday probe body comprises a collection ring, a collection protection insulation device and a protection ring. The external side of the collection ring is sleeved by the collection protection insulation device. The external side of the collection protection insulation device is sleeved by the protection ring. The collection protection insulation device and the collection ring are fit in an interference way. The collection protection insulation device and the protection ring are fit in a clearance way.