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 action of specified operating voltages, lightning overvoltages, and internal overvoltages, there should be no breakdown or surface flashover; under the action of specified long-term and short-term mechanical loads, there should be no damage or destruction; after long-term operation under specified mechanical, electrical loads and various environmental conditions, there should be no significant degradation; the hardware of the insulator should not produce any noticeable corona discharge under the operating voltage to avoid interference with radio or television reception. As insulators are widely used devices, their connecting hardware is also required to be interchangeable. Moreover, the technical standards for insulators necessitate various electrical, mechanical, physical, and environmental condition tests based on different models and usage conditions to verify their performance and quality.