The main function of insulators is to achieve electrical insulation and mechanical fixation, for which various electrical and mechanical performance requirements are specified. This includes not experiencing breakdown or surface flashover under the specified operating voltage, lightning overvoltage, and internal overvoltage; not causing damage or destruction under the specified long-term and short-term mechanical loads; not showing significant degradation after long-term operation under specified mechanical, electrical loads, and various environmental conditions; and not producing noticeable corona discharge under operating voltage in the insulator hardware 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 dictate that various electrical, mechanical, physical, and environmental condition tests be conducted on the insulators based on their models and usage conditions, to verify their performance and quality.