https://www.mktester.com/hv-switch-tester/isolation-switch-contact-pressure-tester.html
Isolating switch is a kind of high voltage switching equipment used widely in power system.Because the outdoor isolating switch is completely exposed to the atmospheric environment, its operation conditions are relatively bad, easy to produce mechanical or electrical faults.In particular, the contact part of the contact is vulnerable to rain, dust and harmful gases, resulting in poor contact and fever. The spring that provides the pressure of the contact will be annealed to reduce the pressure due to fever, which leads to the formation of a vicious cycle of contact fever and eventually burn out the contact.In maintenance often only pay attention to the replacement of obvious failure and fracture of the spring, and the pressure of the spring can not be judged and replaced, so that in the operation again, the distribution of Each Contact Current Will Be Different Because of Different Pressure,