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Working principle of DC resistance tester

:2024-04-07 15:57:29:

DC resistance tester is a precision instrument used for measuring resistance, with a wide range of applications, including the power, electronics, and communication industries. In the power industry, it can be used to test the DC resistance of equipment such as transformers, generators, and motors to ensure their normal operation and safety. In the electronics industry, it is an important tool for testing the resistance values of various electronic components such as resistors, capacitors, and inductors, helping to determine the performance and quality of the components. In the communication industry, DC resistance testers are often used to test the resistance values of cables and connectors, determine their quality and connection status, which is crucial for ensuring the normal operation of communication equipment and the stability of signal transmission. Overall, the DC resistance tester is a powerful and widely used measuring instrument, which is of great significance for ensuring the normal operation and performance evaluation of electrical equipment.


The working principle of a DC resistance tester is based on Ohm's law, which means that the resistance is equal to the ratio of voltage to current. The tester generates a constant DC current and injects it into the resistance to be tested, while measuring the voltage values at both ends of the resistance. Then, according to Ohm's law, the resistance value of the resistance is calculated.

Specifically, there is a power supply inside the DC resistance tester that can generate stable DC current. During measurement, the power supply provides a constant current to the measured resistor through specific ports (such as I+, I -). When current passes through a resistor, a corresponding voltage drop is generated at both ends of the resistor. This voltage drop is captured by the tester through another set of ports (such as V+, V -).

The captured voltage signal is amplified by the internal amplification circuit of the tester and converted into a digital signal. Subsequently, this digital signal is processed by the processor to calculate the resistance value based on Ohm's law. Finally, the test results are displayed in digital form on the screen of the tester for users to read.

DC resistance testers usually use the four wire measurement method, which can eliminate the influence of the resistance of the test lead on the measurement results and improve the measurement accuracy. In the four wire measurement method, two lines are used to provide the test current, and the other two lines are used to measure the voltage drop. This ensures that the measured voltage drop is only generated by the measured resistance, thus obtaining a more accurate resistance value.

In addition, to meet different testing needs, DC resistance testers usually have multiple current output gears to choose from. Users can choose the appropriate current level based on the expected value of the resistance to be measured to ensure the accuracy and reliability of the measurement results.

In summary, the DC resistance tester achieves accurate measurement of resistance values by generating a constant DC current, measuring voltage drop, and applying Ohm's law. Its working principle is simple and clear, but in practical applications, attention should be paid to operating standards to ensure the accuracy and reliability of measurement results.


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Kvtester Electronics Technology Co.,Ltd. is a high-tech enterprise specializing in power testing, testing, research and development, production, and sales of testing equipment. It has been engaged in the electrical testing industry for many years, and its products are of high quality. We welcome customers to come and purchase. Service hotline: 0086-27-81778799, to learn more, visit the official website:

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