Q1: What is a clamp-on earth resistance tester?
A1: The clamp-on earth resistance tester can measure the connection resistance of any looped system without using an auxiliary ground rod or interrupting the grounding of the equipment under test. As long as the ground wire or ground rod is clamped with the clamp head, the ground resistance can be measured safely and quickly. It can also be applied to multiple parallel grounding systems. The clamp-on ground resistance tester can measure the leakage current of 1MA, and the neutral line current can reach 20A. This function is especially important when the ground network to be tested contains large noise and harmonics.
Q2: How does a clamp ground resistance tester work?
A2: The basic principle of the clamp ground resistance tester to measure the grounding resistance is to measure the loop resistance. The jaw part of the clamp meter consists of a voltage coil and a current coil. The voltage coil provides the excitation signal and induces a potential E on the loop under the test. Under the action of the potential E, a current I will be generated in the circuit under test. The clamp meter measures E and I, and the measured resistance R can be obtained by the following formula. The formula is R=E/I. This is how a clamp-on ground resistance tester works.
Q3: What is the earth resistance tester used for?
A3: The ground resistance tester can accurately measure the grounding impedance, grounding resistance and grounding reactance of large grounding grids.
- It accurately measures the surface potential gradient in the large-scale grounding grid area.
- Earth resistance tester can measure the contact potential difference, contact voltage, step potential difference and step voltage of large grounding grids.
- Measure the transfer potential of large-scale grounding grids and soil resistivity accurately.
- Digital earth resistance tester is used to measure the on-resistance of the grounding down-conductor.
Tips: Earth resistance tester method: Single clamp method
The single-clamp measurement method, a kind of resistance testing method, is used to measure the grounding resistance of each grounding point in multi-point grounding, and the grounding connection cannot be disconnected to prevent danger. It is suitable for multi-point grounding, can not be disconnected, and measure the resistance of each grounding point.
Resistance tester wiring: Use a current clamp to monitor the current at the ground point under the test.