The main function of insulators is to achieve electrical insulation and mechanical fixation, for which various electrical and mechanical performance requirements are specified. For example, under the action of specified operating voltage, lightning overvoltage, and internal overvoltage, no breakdown or surface flashover occurs; under the action of specified long-term and short-term mechanical loads, no damage or destruction occurs; after long-term operation under specified mechanical, electrical loads, and various environmental conditions, no significant deterioration occurs; the hardware of the insulator does not produce significant corona discharge under operating voltage to avoid interference with radio or television reception. Since insulators are widely used, the connecting hardware is also required to be interchangeable. Additionally, the technical standards for insulators require various electrical, mechanical, physical, and environmental condition tests based on different models and usage conditions to verify their performance and quality.