Verification of Electromagnetic Shielding Scheme for Physical Force-Measuring Weighing Instruments in Strong Electromagn

Case Background

A steel smelting plant requires the upgrading of its furnace hopper weighing device to improve weighing accuracy under high-temperature, strong magnetic and high-electromagnetic conditions. The hopper is located adjacent to high-voltage power distribution cabinets, with several 10 kW variable-frequency water pumps, electric welding machines and other equipment in the vicinity. The maximum magnetic field strength is approximately 60 A/m; radio frequency signals mainly range from 10 MHz to 50 MHz, and the instantaneous peak voltage of the power supply can reach up to 1500 V. The currently deployed equipment is a mechanical lever electronic scale, which exhibits a zero offset of 1.8% and full-scale deviation of 2.3% at this site, failing to meet the industrial requirement (≤1%). Considering the characteristics of this environment, an integrated electromagnetic protection scheme combining multi-layer shielding and signal line filtering is proposed. Virtual laboratory tests and on-site experiments will be adopted to verify the effectiveness of the system, providing references for the reliability operation of weighing instruments under strong electromagnetic environments.