The technical conditions for SF6 load switches in China generally stipulate that the main circuit resistance is ≤ 65u Ω, while similar foreign products are ≤ 42u Ω m. The reason for affecting the circuit resistance value is the magnitude and consistency of the clamping force between the dynamic and static contacts. Generally, a clamping force between 160N-190N is better. In actual operation and use, the clamping force of the dynamic and static contacts may deviate from the correct range value due to the influence of the operation and use environment.

Under the pressure of the compressed spring, a good contact between the dynamic and static contacts is formed. The greater the contact pressure, the better the contact, and the less heat generated by the connector when passing current, thus achieving good conductivity. If the contact pressure is too low, the contact resistance will increase. Under the long-term action of current, the contact will overheat, oxidize, and press the spring to anneal, which will lead to the deterioration of the contact and a vicious cycle until the contact burns out. Therefore, the contact pressure should be controlled within an appropriate range.

In response to the current maintenance status of the power supply system, this portable charging contact pressure measuring instrument (also known as SF6 load switch moving contact clamping force tester) can display the contact pressure of each pair of contact fingers in real time by simply inserting the sensor of the device's simulated contact into the contact position of each pair of contact fingers. Effectively solved a major problem in measuring finger pressure. This portable charging contact pressure measuring instrument (SF6 load switch moving contact clamping force tester) can also be used for SF6 load switch manufacturers to inspect the contact finger pressure; Changing the shape of the pressure sensor can also measure the finger pressure of SF6 load switches.