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 must not experience breakdown or surface flashover; under specified long-term and short-term mechanical loads, they must not suffer from damage or destruction; after long-term operation under specified mechanical, electrical loads, and various environmental conditions, they must not exhibit significant deterioration; the hardware of insulators must 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. Furthermore, the technical standards for insulators necessitate various electrical, mechanical, physical, and environmental condition tests based on different models and usage conditions, in order to verify their performance and quality.