Milliohmmeter test lineUsing the Kelvin four line method, by separating the current circuit and voltage measurement circuit, the influence of the test line's own resistance on the measurement results is eliminated. The specific implementation method is:

Two independent wires: one is used to apply a constant current to the measured resistor (current wire), and the other is used to measure the voltage drop across the resistor (voltage wire).

Contact point design: Kelvin clamps or needle probes are usually used at the end of the test line to ensure the physical separation of current and voltage measurement points and avoid contact resistance mixing into the measured values.

　　Milliohmmeter test lineTypical application scenarios:

Electrical connection quality inspection

Grounding resistance test: Verify the reliability of the grounding system connection, ensure timely introduction of leakage current into the ground, and prevent the risk of electric shock.

Wire connection detection: Detect the resistance of connection points such as cables, terminal blocks, and terminals to prevent overheating or fire caused by poor contact.

Contact resistance measurement: Evaluate the contact performance of components such as switches, sockets, relays, etc., and optimize the stability of electrical systems.

Industrial equipment maintenance

Transformer winding detection: Measure the DC resistance of the winding to determine inter turn short circuits or insulation aging.

Motor winding analysis: detect the balance of motor winding resistance and diagnose motor faults.

Fault location of power cables: locate cable damage or loose joints through resistance changes.

Research and high-precision manufacturing

Material resistivity testing: measuring the resistivity of metals, semiconductors, and other materials to support the development of new materials.

Precision component production: Monitor the consistency of resistance values in the production of electronic components such as resistors and inductors.