124 results about "Ohmmeter" patented technology

The invention discloses a graphene-based strain measuring or motion sensing device. The device is formed by the following steps: a layer or a plurality of layers of graphene film layers are combined on a flexibly insulating substrate; two ends of the graphene film layer are led out through electrodes and connected with ohmmeters, wherein the device is closely combined on the surface of an object to be detected, or a plurality of the devices are closely combined on the surface of the object to be detected, so that the strain variation measurement or motion monitoring can be realized. The device disclosed by the invention has the advantages of simple manufacturing method and capabilities of being suitable for large-scale production such as surface mounting and the like, and being applied to various types of environments and deformed surfaces; especially, the influence on the object to be detected is small, so that contactless measurement can be realized, and the device is suitable for monitoring biological motion. The invention further discloses a manufacturing method and a measuring method for the device.

The invention relates to a conductive thickener and an electronic device and a solar battery comprising electrodes formed by the conductive thickener. The conductive thickener comprises conductive powder, a metal glass and an organic carrier, wherein, the metal glass comprises an alloy comprising at least two chemical elements selected from a chemical element having a low resistivity, a chemical element formed a solid solution with the conductive powder or a chemical element having a high oxidation potential, and wherein, the chemical element having the low resistivity has a resistivity about 100 micro-ohmmeter-cm, and the chemical element having the high oxidation potential has a Gibbs free energy absolute value about 100 kilojoule / moore or more.

The invention discloses a method for detecting positional deviation among layers of a multilayer printed circuit board, which comprises the following steps: A, selecting an even layer or an odd layer in the printed circuit board, and setting a plurality of circular alignment marks of which the diameters are in equidifferent and progressive increase on the selected layers; B, etching the circular alignment marks on the layers to form substrates, and overlying and pressing the layers in the printed circuit board into a whole according to the circular alignment marks; C, drilling holes on the circular alignment marks from the outermost layer of the printed circuit board, wherein the bore diameters of drilling holes are the minimum bore diameter in the circular alignment marks; D, etching copper materials around the drilling holes at the outermost layer of the printed circuit board to form circular rings so as to enable the drilling holes to be independent mutually; and E, measuring the short-circuit or open-circuit situation between the circular alignment mark with the minimum diameter and the other circular alignment marks by adopting an ohmmeter to judge the alignment accuracy of an inner layer. The method can detect the positional deviation among the layers of the multilayer printed circuit board simply and quantitatively.

The invention discloses a page tabular display method. The page tabular display method comprises refreshing content of a display area in real time, and calculating the display area in real time according to received operation; customizing a display style, and respectively carrying out render on a column and a line according to a column type and a line type; and storing table data on a first array. According to the page tabular display method, tabular data display is enabled to be convenient and rapid, a page deadlock problem caused by large data volume loading is solved, and the defects that digital ohmmeter (DOM) elements are overmuch, and loading and search is slow when table data volume is large are overcome.

A method for measuring degradation of electrical power system device insulation utilizes a conductive composite sensor. A selected polymeric matrix of the conductive composite provides a sensor resistance response that correlates to the mechanical degradation of the insulation. The sensor may be embedded in the windings, core or stator of the electrical power system device and wired to a connector on the electrical power system device for interrogation by an ohmmeter.

A ceramic armor system with built-in conductive circuit attached to a ceramic component. The conductive circuit can be accessed by a user at contacts provided in the system. The circuit is arranged so that damage such as cracks that occurs within the ceramic component can propagate into the conductive material forming the circuit and thereby cause a rupture in the conductive circuit. An electrical probe such as an ohmmeter is used to measure the conductive circuit resistance that is then checked against an expected value. The results are used to determine if the ceramic armor component is in operable condition.

A method and apparatus is provided for determining when a battery, or one or more batteries within a battery pack, undergoes an undesired thermal event such as thermal runaway. The system uses a conductive member mounted in close proximity to, or in contact with, an external surface of the battery or batteries to be monitored. A resistance measuring system such as a continuity-tester or an ohmmeter is coupled to the conductive member, the resistance measuring system outputting a first signal when the temperature corresponding to the battery or batteries is within a prescribed temperature range and a second signal when the temperature exceeds a predetermined temperature that falls outside of the prescribed temperature range.

The invention provides an experimental device for integrity evaluation of an oil and gas well fracturing working condition pitshaft. The outer portion of an external pressure cylinder sleeve is connected with an external pressure loading pipeline and a high-pressure pump, and a three-dimensional loading hydraulic cylinder is arranged in the external pressure cylinder sleeve and connected with a hydraulic control module. A rock mass and pitshaft physical model is placed in the middle of the three-dimensional loading hydraulic cylinder and composed of a sleeve, a cement ring, a rock mass and a perforation hole. A sleeve inlet is connected with an internal pressure loading pipeline and a high-pressure pump and further connected with a high-pressure gas cylinder and a gas compressor, an outer wall of the sleeve is connected with a strain sensor, and the cement ring is internally connected with an air pressure sensor and an ohmmeter. The invention further provides an experimental method for evaluating pitshaft integrity by utilizing the device. According to the experimental device and method for integrity evaluation of the oil and gas well fracturing working condition pitshaft, the oil and gas well fracturing and production process can be simulated, the integrity evaluation result of the fracturing working condition pitshaft is high in credibility, and the experimental basis is provided for oil and gas well sleeve design, well cementation and fracturing parameter optimization.

A digital display tape measuring device is disclosed having a display screen exteriorly for displaying the measured distance. A tape having electrical conductivity capabilities and an insulator disposed longitudinally along the tape dividing the tape into two electrical conductors, and having a tip thereof electrically connecting both of the electrical conductors together such that an electrical circuit is formed with resistance that varies as the tape is extracted from device. An ohmmeter electrically coupled across the electrical circuit for measuring the circuit resistance. A microprocessor having inputs thereof coupled to outputs of the ohmmeter and having outputs coupled to said display screen. The microprocessor computes measurements made by as a function of the resistance measured by the ohmmeter.

Provided is an ohm contact imitation resistor test apparatus and a test method. The method comprises the following steps: (1) ventilating; (2) putting a product to be tested on the base plate of a frame shape support, wherein the test points aim at the metal electrodes and a positioning clamp can be designed according to different products; (3) opening a cylinder switch and pressing downward pressure plates to make the metal electrodes on the pressure plates to fully contact with the product to be tested; (4) reading the resistance value on the ohmmeter; (5) closing the cylinder switch, raising the pressure plates and removing the product tested. The advantages are: (1) the test apparatus helps minimize technology process and save production time; (2) the manufacture process of the test apparatus is simple and the cost of the test apparatus is low; (3) the test apparatus has good stability and easy operation; (4) the test apparatus has a wide application range.

A system includes a temperature chamber (100), a text fixture (402), a test coupon (400), a data acquisition unit (404), an ohmmeter (406) and a computer (410). The temperature chamber (100) provides temperature extremes to the test coupon (400). The test coupon (400) includes a substrate (314), one or more vias (418-429) and traces (402-412) connecting the vias. The data acquisition unit (404) continuously measures a resistance value of the circuit formed by the vias (418-429) and traces (402-412) during temperature cycling of the test coupon (400) held by the test fixture (402). The ohmmeter (406) measures the temperature of the test coupon (400) with a thermocouple. The data is used to detect failures of the materials in the test coupon (400) during the temperature cycling.

The invention relates to a device and a method for measuring crack expanding rate of a compact tension specimen, which are applied to continuous high-accuracy measuring of fatigue crack expanding, stress corrosion cracking, corrosion fatigue and other experiments of the compact tension specimen. The device comprises the following hardware of a computer, a GPIB (general purpose interface bus ) card, a multi-channel high-power relay card, a high-accuracy nanovolt micro-ohmmeter, a data switching unit, a high-stability direct current power supply, a shielding conducting wire or a double-strand insulation platinum wire. The device comprises the following software of direct current potential drop crack expanding rate measuring software and a user interface thereof. The device has the advantage that the relay switch is controlled by the direct current potential drop crack expanding rate measuring software to reversely change the direction of the direct current, so as to solve the problem of interference to the measuring accuracy and stability by the contact resistances of lead wire and specimen and electric potential produced by the temperature difference at both ends of the lead wire.

The invention relates to a device and a method for detecting temperature characteristics of a temperature sensor. The device comprises an ohmmeter I, an ohmmeter II, an ohmmeter III, a heating furnace IV, a temperature controller V, a power supply circuit, a temperature sensor A to be measured, a temperature sensor B to be measured, a temperature sensor C to be measured, a sensor for controlling the temperature of the furnace, connectors XP1 / XS1-XP4 / XS4 and a panel. The detection method comprises the following steps of: turning on a power source of the device; presetting the furnace temperature and selecting temperature-raising output voltage; respectively measuring the changes of the temperature sensor A, the temperature sensor B and the temperature sensor C which correspond to the furnace temperature from a low temperature period to a high temperature period, recording a plurality groups of relevant data for the corresponding change of resistance in a table; and thereby analyzing the temperature characteristics of the temperature sensor. The method is simple, direct and directviewing, improves the detection precision and the detection efficiency of data, can save energy and reduce emission, not only can be used for researching the temperature characteristics of the temperature sensor, but also can be used for electricity experiment teaching.

Disclosed is a Hall Effect instrument with the capability of compensating for temperature drift consistently, accurately and in real time of operation. The instrument embodies a four-point ohmmeter circuit measuring Hall Effect sensor resistance and tracking the effect of temperature on the Hall Effect sensor. The instrument takes into account a relationship between the temperature and a temperature compensation index on a per probe basis, which has exhibited a deterministic difference observed by the present inventor.

The invention belongs to the field of electrical tests, and relates to an automatic testing device and a testing method for product electronic impedance characteristics. The invention provides a matrix automatic impedance tester, which comprises a test box, a digital ohmmeter and a main control computer, and is characterized in that: n test contacts are arranged in the text box, each test contact is connected with a positive end and a negative end of the digital ohmmeter to form a testing access; each testing access is provided with a programmed switch; the main control computer is internally provided with two digital interface cards used for controlling positive and negative input ports of the digital ohmmeter; and output ends of the digital interface cards are connected with driving ends of the programmed switches. By adopting the matrix automatic impedance tester and the testing method, the testing personnel do not need to perform manual walk through and record test data manually as before, and can hand over the subsequent measurement to a program for automatic completion by inputting a test netlist and connecting tested equipment, thus the testing efficiency, testing security and testing accuracy are significantly increased.

Systems and methods for fatigue testing one or more stents based on measured electrical resistance levels of each stent. Pairs of lead lines from an ohmmeter are connected to a respective stent. The respective stent is mounted onto an expander having an interior tapered portion into which a correspondingly tapered expansion pin is received. Cyclic loading strains are applied to the respective stent as an expansion pin is inserted into a corresponding one of the expanders. Stent fracture or failure occurs when cyclic loading exceeds the stents architectural and material capacity. Such fracture fatigue or failure is identified by increased electrical resistance levels. Resistance may be continuously monitored to more readily identify the onset of fatigue or failure. The expansion pins extend from a movable plate, and the expanders comprise a part of corresponding stations that extend from a fixed plate.

An apparatus for rapid thermal testing of samples consisting of a single sample chamber in which the samples are preferably arranged circularly around the opening through which a fluid of varying temperature, preferably air, is introduced to provide for rapid, uniform cooling and heating of the samples. The samples are preferably uniformly spaced to allow for uniform air flow. The samples are mounted in slots which are preferably oriented radially outward from the opening. The sample mounts comprise electrical connectors which form a network connected to at least one ohmmeter for measuring the resistance of the samples. The samples preferably comprise test coupons, each with multiple daisy-chained nets of vias or other components to be tested. Also a method for thermal testing of samples consisting of steps to characterize the samples before the test is run. First, the resistance of the samples which correlates to each target temperature is determined, and the time required for the samples to reach that resistance when they are heated or cooled is measured. Then, for reliability testing, the temperature of the samples is cycled between the target temperatures, where the cycle segment durations are given by the times measured in the characterization steps.

The invention relates to a variable resistance characteristic demonstrator, in particular to variable characteristic demonstrators of a thermal resistance, a photoresistor, a piezoresistor, a hygristor and a magneto resistor. The circuit comprises an Ohmmeter, a change-over switch, the thermal resistance, the photoresistor, the piezoresistor, the hygristor, the magneto resistor, a 555 integrated circuit, a resistor, a capacitor and a light emitting diode; the variable resistance characteristic demonstrator is characterized in that one end of the thermal resistance, the photoresistor, the piezoresistor, the hygristor, the the magneto resistor and the Ohmmeter is connected with the positive electrode of a DC power supply after parallel connection, while the other end thereof is connected with a pin 2 and a pin 6 of the 555 integrated circuit through the change-over switch and the resistance, one end of the variable resistance is connected with the change-over switch, while the other end thereof is connected with the negative electrode of the DC power supply. By adopting the technical proposal, the variable resistance characteristic demonstrator has the advantages and active effects that the variable characteristics of the thermal resistance, the photoresistor, the piezoresistor, the hygristor and the magneto resistor can be demonstrated through the reading changes of the Ohmmeter and the working state of the light emitting diode with high visualization and low cost.

A membrane electrode short-circuit detection device for proton-exchange membrane fuel battery and the detection method are provided in the invention. The device is to connect two conductive flat plates and the DC power source, in the connecting circuit, an ohmmeter is connected in; the method is to clap the detected membrane electrode between two conductive flat plates and giving the small constant current on membrane electrode to record the resistance change along the time. If the resistance increases with the time, the membrane electrode has no short circuit; if the resistance is constant, the membrane electrode has the short-circuit point. The merits of invention are in that: it does not need any special device and ha low cost; the method is simple and easy to operate; the detection result can be get from the ohmmeter. The detection process has no destroy to the membrane electrode. The invention provides the reliable device and method and has important meaning for improving membrane electrode quality.

The invention discloses a carbon dioxide fracturing method. The method includes the steps that first, carbon dioxide fracturing devices are assembled; second, an ohmmeter is used for detecting whetherthe resistance value between a filling valve and a release tube is normal or not; third, the carbon dioxide fracturing devices assembled in the first step are loaded and transferred to a mine after passing examinations; fourth, whether the resistance between each carbon dioxide fracturing device and a wire is normal or not is measured, a layer of blasting holes are drilled in the mine, and the carbon dioxide fracturing devices are put into the corresponding blasting holes; fifth, the hole opening of each blasting hole is covered with a bamboo chip and then is covered with a tarpaulin and earth bags; and sixth, a warning region is made around each carbon dioxide fracturing device, and an ignition device is pressed to start the carbon dioxide fracturing devices for detonation. By means of the carbon dioxide fracturing device, reuse can be realized, using cost is greatly reduced, powerful thrust generated momently is used for tearing materials, the same carbon dioxide fracturing devicescan be connected through the corresponding wires, and the advantages of being low in labor intensity, large in fracturing force, safe and good in fracturing effects are achieved.

The invention relates to a performance test device and method for a temperature switch. The device comprises a heating circuit, a temperature detecting circuit and a temperature switch status indicating circuit. The heating circuit comprises a first power supply and a resistance heating band. The temperature switch status indicating circuit comprises an indicating device, a second power supply, and an interface which are in successive series connection, wherein the interface is used for connecting the temperature switch. The temperature detecting circuit comprises a platinum thermal resistor which is pasted on the resistance heating band, and a digital ohmmeter which is connected to the platinum thermal resistor. The digital ohmmeter is powered by the second power supply. According to the method, the heating circuit is used for heating; the temperature detecting circuit is used for determining whether a switching threshold of the temperature switch is reached; when the switching threshold is reached, the temperature switch status indicating circuit is used for determining whether the temperature switch is normal or not. The device and method are easy to operate; the detection is quick and efficient; the detection result is visual and has high accuracy; the device and the method are compatible with multiple types of temperature switches.

The invention relates to the technical field of human vaccines, in particular to a human vaccine freezer comprising a cylinder, a sealing mechanism, a temperature detection mechanism, an ejection mechanism, a refrigeration mechanism and vaccine bottle bodies; according to the human vaccine freezer, external temperature can be measured through a thermistor; when the temperature rises, the resistance increases, and a pointer of an ohmmeter moves; a fountain pen is moved along with a supporting rod, and the movement path of the fountain pen is drawn on a scale whiteboard; when the temperature falls, the resistance decreases, and the fountain pen is driven by a rotating disk to rotate reversely, so that the measurement of environment temperature is achieved; medical staff can judge whether cold chains are disconnected and the activity of vaccines is normal in the transportation process of the vaccines according to the movement path of the fountain pen in use; deactivated vaccines are prevented from being used by the medical staff effectively, and the safety of the vaccines is ensured; vaccine bottles are placed in placement grooves, and the temperature difference in the cylinder is reduced effectively; and when the medical staff use the vaccine bottles at an upper layer, the cold storage of the vaccine bottles at a lower layer is not affected.

The invention belongs to the field of material environmental fatigue experiments, particularly relates to a corrosion fatigue crack propagation testing device with high-temperature high-pressure circulating water and application and aims to solve the problem of in-situ accurate measurement of fatigue crack length and rate in a high-temperature high-pressure water environment. The device is provided with a high-temperature high-pressure water corrosion fatigue crack propagation testing system, a high-temperature high-pressure water circulating system, a high-pressure kettle and a fatigue machine. The high-temperature high-pressure water circulating system is connected with the high-pressure kettle to form a circulating circuit, a CT (compact tension) specimen is connected with a loading portion of the fatigue machine, and the high-temperature high-pressure water corrosion fatigue crack propagation testing system is connected with the CT specimen through a wire and comprises a computer,a nanovolt micro-ohmmeter, a data acquisition switch unit, a direct-current power source, a GPIB board card, a compression seal part and direct-current potential drop testing software. In-situ accurate measurement of fatigue crack length of the CT specimen in the high-temperature high-pressure water environment can be realized.