395 results about "Electrical resistance survey" patented technology

A system and method for measuring a resistance or a resistance per square, R_sq, of a material having a surface using a multi-point probe including four or more collinear contact points placed in the interior of the sample, the method including: making a first measurement using a first set of probe electrodes for inducing a current and a second set of probe electrodes for measuring the voltage difference when the current is induced; making a second measurement using a set of probe electrodes different from the first set for inducing a current and a set of probe electrodes different from the second set for measuring the voltage difference when the current is induced; and using a known relationship among the currents induced, the voltages measured, the nominal probe positions and the resistance per square to determine the resistance per square such that measurement errors resulting from positioning of the probes are reduced.

Measurement of the series track resistance of a working and counter electrode pair in an electrochemical test strip provide error detection for multiple variations in the quality of the test strip, as well as the operation of strip in the test meter. In particular, a single measurement of series resistance can be used to detect and generate an error message when an incorrect reading is likely to result due to (1) damaged electrode tracks, (2) fouled electrode surfaces, (3) dirty strip contacts, or (4) short circuit between the electrodes.

A battery measuring device includes a temperature measuring unit which measures temperature T1 of a secondary battery, a resistance measuring unit which measures an AC resistance value and a DC pulse resistance value of a first discharging period of the secondary battery at the temperature T1, and an estimating unit in which an electric resistance Re1 and a reaction resistance Rc1 of the secondary battery at the temperature T1 are considered as,

• • Re1=AC resistance value
  • Rc1=DC pulse resistance value of the first discharging period−AC resistance value, and which estimates at least an internal resistance of the secondary battery using the temperature T1, electric resistance Re1 and reaction resistance Rc1.

An apparatus is disclosed that includes a resistance measuring unit operable to determine a solution resistance Rsol and a charge transfer resistance Rest of a battery; and at least one computer-readable non-transitory storage medium comprising code, that, when executed by at least one processor, is operable to provide an estimate of the present value of the battery by: comparing Rsol and Rct to historical deterioration transition information; estimating the number of remaining charge cycles before a discharge capacity lower limit is reached by the battery using the comparison; and estimating the number of remaining charge cycles before a discharge time lower limit is reached by the battery using the comparison. The estimate of the present value of the battery includes the smaller of the number of remaining charge cycles before a discharge capacity lower limit is reached or the number of remaining charge cycles before a discharge time lower limit is reached.

A method measures a resistance of an element that is operably coupled to receive an AC line voltage. The method includes obtaining a first voltage measurement value V1A from a first side of the element at a first time, and obtaining a second voltage measurement value V2A from a second side of the element at the first time. The method also includes obtaining a first current measurement value IA through the element at the first time, and obtaining a second current measurement value IB through the element at the second time. The method further includes obtaining a third voltage measurement value V1B from the first side of the element at a second time, and obtaining a fourth voltage measurement value V2B from the second side of the element at the second time. The processing device determines the resistance at least in part based on the values V1A, V2A, V1B, V2B, IA and IB. The determination based on an adjusted difference of V2B and V2A.

Disclosed herein are a connector for measurement of electric resistance, by which an electric resistance-measuring apparatus capable of surely performing expected measurement of electric resistance with high precision even to a circuit board having small-sized, protruding electrodes to be inspected, a scatter of projected heights of said electrodes being great, and easy to produce can be constructed, and electric resistance-measuring apparatus using this connector and method of measurement.

The connector has a composite electrode sheet having an insulating sheet body in which through-holes have been formed corresponding to electrodes to be inspected, movable electrodes supported movably in a thickness-wise direction within the through-holes, and stationary electrodes each formed in the vicinity of openings of the through-holes on a front surface of the insulating sheet body in a state coming into no contact with the movable electrodes, front-side and back-side anisotropically conductive elastomer layers respectively laminated on the front surface and back surface of the composite electrode sheet, and an external leading terminal electrically connected to the stationary electrodes. The movable and stationary electrodes are electrically connected at the same time to corresponding electrodes to be inspected through the front-side anisotropically conductive elastomer layer.

A two-track piezoresistive cantilever detects explosives in ambient air by measuring resistance changes in the cantilever when one piezoresistive track is pulse heated to cause deflagration of explosive adhered to the surface of the cantilever. The resistance measurement is through the second piezoresistive track, which is located at the most resistance-sensitive area. The resistance change of this track is caused by the temperature change of the cantilever as well as the bending of the cantilever due to bi-material thermal expansion. The detecting method using this novel cantilever avoids the use of any optical components such as a laser and position sensing detector (PSD), which are necessary in traditional detecting systems using cantilevers. Therefore, it can extremely reduce the complexity of the detecting system and make a portable chemical detection system possible that is small, less expensive, and able to be mass produced and is particularly useful for the detection of explosives.

The invention provides a frequency sweeping test method for measuring the power frequency ground resistance of a grounding device and a test instrument for the frequency sweeping test method, which are used for solving the problems that in the conventional measurement, wires are inconveniently laid, measurement is interfered and the like. The measuring method comprises the following steps of: arranging a voltage electrode, a current electrode and a lead according to a preset ground resistance test way; selecting a frequency with a small interference signal as a test frequency; measuring ground impedance at the selected test frequency; and computing the power frequency ground resistance according to the measured ground impedance. The adopted test instrument comprises a variable-frequency alternating current power supply, a current sensor, a voltage divider, an isolating transformer, a signal acquisition device, an analog/digital (A/D) convertor and a portable personal computer (PC). The frequency sweeping test method for measuring the power frequency ground resistance of the grounding device and the test instrument for the frequency sweeping test method can effectively avoid each interference frequency and acquire a reliable test result.

An improved corrosion measurement system for determining the rate of corrosion of a fluid medium. The system is comprised of a highly sensitive excitation and amplification electronic circuitry for registering and displaying the stable and accurate measurement results. A novel current feedback amplifier maintains a constant alternating current voltage across the reference element, by simultaneously controlling the current through the serially connected reference and corroding elements, thereby keeping the corrosivity measurement independent of the probe's ambient temperature. The unique unitized electrical resistance measurement probe is also temperature stabilized using thermally bridged and balanced metallic elements; the first reference element being coated with an impermeable insulating coating, the second, the sacrificial corroding element, being fully exposed to the corrosive fluid medium.

A method of establishing a damnification self-diagnosis system for carbon fiber enhancement resin base composite material is characterized in that the steps includes: (1) measuring the front and the rear electrical resistances of different type composite materials with epigene actions of stretching, impacting and bending by a electrical resistance measuring instrument, building a stress-electrical resistance database of the composite material, determining the damnification of the composite material by using a ultrasound scanning method, and determining the corresponding relation of damnification-electrical resistance variation; (2) analyzing and processing the composite material electrical resistance variation by a computer, diagnosing whether the composite material having damnification or not real time, and generating automatically a abridged general view of the composite material status. The advantage of the invention is that by means of using the conductivity characteristics of the composite material, the composite material is taken as an inductive element for its mechanics and electrology performance, so as to self-diagnosing the damnification of the composite material. The system has the characteristics of real time monitoring, accurate diagnosis, and the system is visual and intelligible.

The invention relates to a method and an instrument for measuring the shock ground resistance of a transmission line tower. The method comprises the following steps: generating incident current by a shock current generator and filling the incident current into the ground; collecting the grounding voltage and the current of the tower by a data collecting device; carrying out treatment and linear amplification on the collected data by an MCU control panel to solve the voltage response of a grounding body under the action of standard lightning current and obtain an equivalent voltage um and a current peak im; and finally, obtaining the shock ground resistance of the tower according to a formula of Rch=um/im. The instrument comprises a current pole lead connecting plug, a grounding device connecting plug, controlled silicon, a charging board, a voltage-multiplying generator, a voltage collecting board, a current collecting board, a battery and a main control board, wherein the current polelead connecting plug is connected with the charging board and the voltage-multiplying generator and then connected to the main control board; the controlled silicon is connected to a circuit in series; the voltage collecting board is connected with a voltage pole lead connecting plug, the grounding device connecting plug and the main control board; the current collecting board is connected with the current pole lead connecting plug, the grounding device connecting plug and the main control device; and the battery is directly connected to the main control board.

Battery insulation resistance measurement methods, insulation resistance measurement methods, insulation resistance determination apparatuses, and articles of manufacture are described. According to one aspect, a battery insulation resistance measurement method includes determining a voltage of a battery, determining a voltage of a first terminal of the battery with respect to a ground reference, determining a voltage of a second terminal of the battery with respect to the ground reference, and using the voltages of the battery, the first terminal and the second terminal, determining an insulation resistance of the battery with respect to the ground reference.

The invention discloses an insulation resistance and grounding resistance comprehensive tester based on a programmable power supply. The tester comprises the programmable power supply, a signal acquisition and analog/digital converter, a microcontroller, a keyboard and display circuit and an alarm and control circuit, wherein state switchover control software is arranged in the microcontroller. The tester has a basic operating principle that: the microcontroller switches an operating state of the tester, namely an insulation resistance testing state or a grounding resistance testing state, through the state switchover control software, and controls the programmable power supply to output direct current high voltage or alternating current high current serving as a testing power supply of electrical equipment to be tested according to the operating state of the tester; and the testing power supply is input into the microcontroller through the signal acquisition and analog/digital conversion circuit to perform closed-loop control and resistance measurement. The tester works stably, has high testing accuracy and integrates measurement, control and display; and moreover, parameters and alarm points can be independently set, function switch can be realized in an insulation resistance test and a grounding resistance test, and the safety of the electrical equipment is convenient to detect.

A printed circuit board (PCB) having an integrated strain gage. In one embodiment, a PCB includes a component footprint suitable for mounting an electronic component. A strain gage is integrated into the PCB in a location under the component footprint. The strain gage includes at least one electrical conductor that is accessible for resistance measurements.

A probe resistance measuring method includes measuring first resistances at three or more nodes by making contact at least a part of a plurality of probes of a probe unit with three or more pads for resistance measurement based on a first correspondence relation. The measured resistances are stored as a first measurement result and contact resistances of the plurality of probes of the probe unit are calculated based on the first measurement result.

A contact resistance measurement method is composed of: placing a first probe onto a first pad connected to an integrated circuit; placing a second probe onto a second pad electrically connected to the first pad; placing a third probe onto a third pad electrically connected to the first pad; measuring a first resistance between the first and second probes; measuring a second resistance between the second and third probes; measuring a third resistance between the third and first probes. A contact resistance between the first probe and the first pad is calculated from the first to third resistances.

The invention provides a micro-ohm resistance measurement system based on a LabVIEW platform and aims to solve the technical problem that low resistance (contact resistance between a movable contact and a static contact of a circuit breaker, a lead resistance and the like) is inaccurately measured in the field of electronic measurement. The system comprises hardware and software, wherein the hardware consists of an alternating current constant current source, a reference signal source, a low-noise pre-amplifier, a data acquisition card, a direct current power supply and a computer; and the software consists of a data acquisition control module, a LabVIEW digital filtering module, a LabVIEW cross correlation module and a data postprocessing module. According to the system, a virtual instrument cross correlation detection technology is adopted, so that the micro-ohm resistance is effectively measured; a personalized automatic measurement system which is flexibly and conveniently programmed, concise and high-efficiency, inhibits noise and has high useful signal recovery and extraction capability, measurement accuracy and resolution and stable performance is built; and the system has real-time displaying, storage and playback functions.

The invention discloses a measurement method of series resistors inside a solar energy battery and a measurement system. Current is reversely input into the solar energy battery to replace a second light process of two light measurements commonly used. Because the light processes are reduced, on the one hand, reduction of consumed time and enhancement of measurement efficiency accord with market status that demand of the solar energy batteries surges, on the other hand, the service life of a light source is prolonged. Maintenance of light-emitting simplicity of the light source can ensure the precision the measurement, thereby the demand of maintenance is reduced, the operation cost is reduced, and the measurement of the solar energy battery is more effective.

A method for measuring an area resistance of a magneto-resistance effect element which includes an upper-barrier layer having a first sheet resistivity Rt, a barrier layer, and a lower-barrier layer having a second sheet resistivity Rb, includes a resistance measurement step, a sheet resistivity measurement step and a establishing step. The resistance measurement step is the step of measuring a resistance R of the magneto-resistance effect element by using predetermined terminals. The sheet resistivity measurement step measures the first sheet resistivity Rt and the second sheet resistivity Rb. The establishing step determines the area resistance RA of the magneto-resistance effect element using the first sheet resistivity Rt, the second sheet resistivity Rb, the resistance R and the intervals among the predetermined terminals.

The invention discloses a dynamic interference potential test system for a buried pipeline. The dynamic interference potential test system comprises a polarized probe, a high-frequency data acquisition device and a data processing device. As the polarized probe replaces a traditional copper sulfate reference electrode, valid data can be provided for corrosion risk assessment of a pipeline at a defect point of the corrosion protection layer of a simulating pipeline, and at the same time potential errors brought by the placement position of the traditional copper sulfate reference electrode are avoided; excavation and measurement for soil electric resistance around the buried pipeline are not needed, a test method is simplified, and further errors brought by orientation of measurement for soil electric resistance are eliminated. The high-frequency data acquisition device is used for acquiring data, and then the data is transmitted to the data processing device for Fourier transform, so that conversion from time domain to frequency domain of the AC-DC superimposed dynamic potential can be obtained, the frequency component of stray current can be accurately judged, and the size of DC potential and the source and size of AC interference can be accurately obtained.

The invention provides an electrical equipment loop resistor test system and a contact state evaluation method. According to the requirement for performance detection of conductive loop nodes of various kinds of electrical equipment, characteristics of contact resistors of the conductive loop nodes of the electrical equipment and a basic range of loop resistor measuring are integrated, and a supercapacitor is adopted to generate kilo-ampere-level long-wave-tip impact currents on the basis that electromagnetic interference resistance and measurement accuracy are met. According to loop resistor difference reflected by the conductive loop nodes (a GIS conductive loop, a high-voltage breaker, a high-medium voltage isolating switch, a high-medium busbar and the like) of the electrical equipment of an electric power system, loop resistance values of the electrical equipment are accurately measured, the contact state of the electrical equipment is evaluated through the change rate along with impact current increase of loop resistors, and the defect that a traditional test method judges only through a management value.

This invention discloses an impact-current measuring method and the corresponding device that is to settle the existing defect of the large volume and low measurement accuracy of the micro-ohm resistance measurement device. The controlling unit controls the closing of switch of the charging circuit, the open of switch of the discharging circuit making the controllable electric power source in the charging circuit charge a storage capacitor. Then the controlling circuit opens the charging circuit switch and closes the discharging circuit switch sending the triggering signal to the sample unit at the same time. The storage capacitor generates the impact current to the non-measured resistance and the sample unit receives the triggering current and voltage data of the non-measured resistance through the current and voltage sensors in the discharging circuit and feedbacks to the controlling unit which reads the data and gets the resistance value after computer's process. The measuring device following the this invented method can be widely used to the manufacture of portable and high-accuracy loop resistance-measure device, switch contact resistance meter and the ground meter.