Method and device for detecting resistance

Abstract

The resistance measuring method and device is especially suitable for quickly measuring small resistance and varying resistance according with Ohmí»s law. The resistance measuring device includes constant-current pulse source, four-end network containing the measured resistance, high input impedance amplifier, real-time measuring and automatic recording display circuit for voltmeter, and digital millivoltmeter. It measures resistance through generating constant-current pulse, producing voltage drop on the measured resistance, amplifying the voltage drop, automatic conversion between reading state and holding memory state and recording and displaying voltage drop. During measuring resistance change, given voltage synchronous with the constant-current pulse is added into the four-end network, and the varying voltage drop the constant-current pulse produces on the measured resistance is measured by means of potential approaching method and further differential method.

Description

technical field [0001] The present invention relates to a measurement method and a measurement device, more specifically to a resistance measurement method and a measurement device, especially suitable for transient measurement of low resistance of solid or liquid conductors, when the measured object changes with the environment such as temperature The measurement of the small change resistance value, and complete the fast resistance measurement of the measured object in an instant. Background technique [0002] Resistance is a physical parameter of various materials, which is defined as the ratio of the voltage drop V on the measured object when a constant current I passes through the measured object to the constant current I, expressed as R=V / I. [0003] At present, the commonly used methods for measuring the resistance of conductor materials can be mainly divided into three categories, one is the direct reading method, such as the volt-ampere method, and the other is the ...

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Problems solved by technology

In actual use, it is found that the double-arm bridge method has the following disadvantages: the measurement accuracy of μΩ level resistance is not enough, usually the highest measurement accuracy is 1μΩ, and its error is more positive than the true value of resistance; when measuring low resistance, due to the need to use Relatively large power supply current, so the DC stabilized power supply is large in size, heavy in weight, and thick in test wires, which brings inconvenience to testing and carrying; during the test process, it takes a long time to adjust, and it is impossible to quickly measure the resistance value , thus making it difficult to measure the continuous variation of the resistance value; during the measurement process, due to the large test current and long adjustment time, the temperature of the object under test will rise, making the test conditions unstable, resulting in a comprehensive test error

[0008] The above-mentioned traditional volt-ampere method, bridge method, and potentiometer method are not suitable for this special occasion and the resistance measurement of the conductor under special requirements.

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