What is the difference between the insulation resistance tester and the ground resistance tester, what's the general use of the three?,
A ground resistance tester is used to measure the contact resistance between ground electrodes (plates) buried in the ground and the measured resistance values, such as below 20 ohms, are generally small
The two traditional testers are similar in shape, with a rocking handle and a pointer display window
An insulation resistance tester is used to measure the magnitude of the insulation resistance between two conductors. The resistance is usually measured by a very large value, such as 1 ohms or more
