How to effectively solve the problem of grounding anti-static chair
Some customers who have purchased anti-static chairs often complain that their anti-static performance is unstable, resulting in the static discharge of static electricity. After a specific analysis, the main reason was that the anti-static chair did not have a good grounding. The question is coming, how can the anti-static chair be well grounded?
According to the requirements of ESD S20.20, the resistance value of the anti-static chair should be less than 109Ω. In the monitoring test of ESD STM12.1 chair resistance, it is required to test the resistance of the chair, seat back, armrest and so on to the wheel, and this requirement is required. If the wheel is made of an insulating material, it is certainly not satisfactory because the resistance of the insulating material is greater than 1012 Ω.
There are two ways to solve this problem: replacing the wheel, replacing the wheel with a conductive wheel or dissipating material; the other is to electrostatically ground the antistatic chair, using a grounding chain. If the latter is chosen, the chain must be connected to the conductive material or dissipative material of the chair, to ensure that the grounding chain really works; at the same time, the chain must have a certain length to ensure that it can be grounded through the anti-static floor. Through the chair grounded by the chain, it is only necessary to test the resistance value of each part of the chair to the grounding chain to meet the requirements.