Advantages of Clamp Ground Resistance Testers Compared to Traditional Testing Methods

Compared to traditional voltage and current testing methods, the clamp-on ground resistance tester offers superior performance as follows:
Easy to operate:
Simply clamp the grounding wire to be tested with the jaws of the clamp-on ground resistance tester, and the ground resistance value can be directly read from the LCD screen. In contrast, the traditional voltage-current testing method requires disconnecting the grounding wire from the grounding system and driving voltage and current electrodes into the soil at specified distances as auxiliary electrodes before measurement can be performed.

Accurate measurement:
The accuracy of traditional voltage-current testing methods depends on the positions of the auxiliary electrodes and their relative placement with respect to the grounding electrode. Additionally, variations in soil resistivity between the voltage and current electrodes and the grounding electrode can affect measurement results. If the placement of the auxiliary electrodes is restricted and cannot meet calculated requirements, this leads to what is known as electrode-spacing error. For the same grounding electrode, different positions of the auxiliary electrodes may result in some degree of variability in measurements, thereby affecting accuracy. In contrast, clamp-on ground resistance testers eliminate electrode-spacing errors; as long as the test loop provided with the tester is first measured during testing and yields an accurate reading, subsequent measurements of ground resistance will also be accurate.
Unrestricted by the surrounding environment:
Traditional voltage-current testing methods require two auxiliary electrodes with specific relative positioning, making them sensitive to environmental conditions; otherwise, measurement accuracy may be compromised. With the advancement of urbanization in China, it is often difficult to find suitable soil around grounding electrodes, as they are frequently covered entirely by concrete. Moreover, locating soil that meets the required spatial configuration can be even more challenging.
Clamp-on ground resistance testers have no such limitations. A single opening and closing of the jaws is sufficient to obtain an accurate ground resistance value. In certain situations, they can measure grounding faults that cannot be detected using traditional methods.
For example, in multi-point grounding systems (such as transmission towers, and some buildings that also use more than one grounding electrode), although the grounding resistance of the electrodes may be within acceptable limits, the connecting wires between the grounding electrodes and the overhead ground wire could develop excessive contact resistance or even open circuits over time. Despite the grounding resistance meeting requirements, the grounding system would still be considered不合格.
Traditional methods cannot measure this condition accurately. However, a clamp-on ground resistance tester can provide correct measurements because it measures the combined resistance of the grounding electrode and the circuit resistance.