A Brief Analysis of Anti-Interference Design for Clamp-Type Ground Resistance Measurement Devices

In complex electromagnetic environments of transmission towers, clamp-type ground resistance measurement devices are highly susceptible to power-frequency magnetic fields, mutual interference between dual clamps, and signal-chain noise. Based on an analysis of the traditional fall-of-potential method and the operating principle of clamp-type measurement, this paper systematically discusses several anti-interference approaches, including outer non-closed magnetic shielding, local magnetic isolation between the excitation clamp and the measurement clamp, intelligent frequency selection and multi-frequency methods, active filter design, and auxiliary calibration based on a reference resistor branch. The analysis indicates that a comprehensive design framework combining structural isolation, frequency-domain avoidance, signal-chain filtering, and reference-assisted correction can effectively improve the anti-interference capability and measurement stability of clamp-type ground resistance measurement devices in transmission tower applications.