The primary function of insulators is to achieve electrical insulation and mechanical fixation, for which various electrical and mechanical performance requirements are stipulated. For instance, under specified operating voltages, lightning overvoltages, and internal overvoltages, they should not experience breakdown or surface flashover; under specified long-term and short-term mechanical loads, they should not suffer damage or destruction; after long-term operation under specified mechanical, electrical loads, and various environmental conditions, they should not exhibit significant deterioration; the hardware of insulators should not produce noticeable corona discharge under operating voltages to avoid interference with radio or television reception. Since insulators are widely used, their connecting hardware is also required to be interchangeable. Moreover, technical standards for insulators vary by model and usage conditions, necessitating various electrical, mechanical, physical, and environmental condition tests to verify their performance and quality.