What Is The Working Principle Of The By2571 Digital Ground Resistance Meter?

What is the working principle of the Connector Hood and Housing BY2571 digital ground resistance meter?
BY2571 digital ground resistance meter abandons the traditional manual hand-cranked power generation working mode, adopts advanced medium and large-scale integrated circuits, and uses DC/AC conversion technology to combine the three-terminal twist and four-terminal twist measurement methods into a new type of ground resistance meter. The working principle is that the DC/AC converter inside the machine converts the DC into a low-frequency constant current of AC, and forms a loop through the auxiliary grounding electrode C and the object under test E. The AC voltage drop is generated on the object under test, which is sent to the AC amplifier for amplification through the auxiliary grounding electrode P, and then sent to the meter for display after detection. With the help of the multiplier switch, three different measurement limits can be obtained: 0-2, 0-20, 0-200.