Grounding resistance testers are widely used in various fields. In the power system sector, grounding devices of equipment such as substations and transmission line towers require regular grounding resistance measurements to ensure good grounding performance and prevent electrical accidents caused by poor grounding. In the communication system sector, the grounding resistance of facilities such as base stations and towers also needs to be strictly controlled to ensure stable transmission of communication signals and normal operation of equipment. Furthermore, in the construction sector, lightning protection grounding systems and electrical equipment grounding systems of buildings also require testing using grounding resistance testers.