The main function of insulators is to achieve electrical insulation and mechanical fixation, for which various electrical and mechanical performance requirements are specified. For instance, under the specified operating voltage, lightning overvoltage, and internal overvoltage, they should not experience breakdown or surface flashover; under the specified long-term and short-term mechanical loads, they should not cause 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. Moreover, technical standards for insulators stipulate that various electrical, mechanical, physical, and environmental condition tests should be conducted on insulators based on their models and usage conditions to verify their performance and quality.