The main 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 from damage or destruction; after long-term operation under specified mechanical, electrical loads, and various environmental conditions, they should not show significant degradation; the hardware of the insulator should not produce significant corona discharge under operating voltage to avoid interference with radio or television reception. Since insulators are widely used, their connecting hardware is also required to be interchangeable. Additionally, the technical standards for insulators vary by model and usage conditions, mandating various electrical, mechanical, physical, and environmental condition tests to verify their performance and quality.