People often eliminate static electricity from human skin, ignoring the elimination of static electricity
The human body itself is a good conductor. The charging of the clothing will cause the human skin to be charged around the body due to electrostatic induction, and a certain static voltage is also formed. Thus, for the operator, there are two possible discharge channels; one is the discharge between the fingertip (skin) and the ground conductor, and the other is the discharge between the work clothes and the ground conductor. Both of these discharges can cause damage to static-sensitive devices. Although the anti-static wristband eliminates the first type of discharge hazard, it does not eliminate the second discharge hazard. This is because the wristband can only eliminate static electricity on the human skin as a good conductor, and it is impossible to leak static electricity on the more insulative clothing.
The way of charging: static voltage (V) on clothing,
Wear leather shoes to walk on ordinary cement floor (usual speed) l200~1500;
Wear plastic slippers to walk on ordinary concrete floor (usually speed) 2500~2600;
Work on the synthetic rubber work surface at 750~2000;
Slightly shake 1500~2800 on the soft leather chair;
Sliding 1500~2800 on a soft leather chair;
Suddenly stood up from the seat 3800~4500;
Taking off the outer garment As can be seen from the above, the static voltage value of the clothing in the human body during various activities has greatly exceeded the electrostatic discharge damage threshold of many electrostatic sensitive devices, which may be caused when touching or approaching these components. Sensitive devices are damaged. It should also be pointed out that it is generally believed that wearing cotton overalls can prevent the static accumulation of clothing and thus it is safe, and the actual view is one-sided.
This is basically the case when the relative humidity of the air is higher than 50%; and when the relative humidity is relatively low, the charge amount of the pure cotton product is significantly increased. Tests have shown that at a relative humidity of less than 30%, the cotton fabric has a charge equivalent to that of polyester, and a shirt is made. When the relative humidity is less than 20%, the amount of charge of the cotton fabric is even higher than that of some chemical fabrics.