Four measures to eliminate static electricity
1. Inhibit the accumulation of static charge;
2. Eliminate the static charge that has been generated.
2. Basic measures to eliminate static electricity
Measures to eliminate static electricity can generally be attributed to "ground"; secondly rely on "device" (static eliminator); thirdly rely on "agent" (add antistatic agent); fourthly rely on "shielding"
1. Ground
Grounding is to connect some anti-static products or other equipment to a ground wire. Use the buried wire method to establish an "independent" ground wire. Make the resistance between the ground wire and the ground less than 10Ω. The function is to discharge the electric charge that may accumulate on the conductor. The static electricity accumulated on the conductor (such as the human body) is usually led away by grounding.
The grounding is implemented by the following methods:
① The human body is grounded through the wrist strap.
② The human body is grounded through anti-static shoes (or shoe laces) and anti-static floor.
③ The work surface is grounded.
④ The test instrument, tool holder, and soldering iron are grounded.
⑤ Anti-static floor and ground mats are grounded.
⑥ Anti-static transfer vehicles, boxes and racks should be grounded as much as possible.
⑦ The anti-static chair is grounded.
2. Use static eliminator
For example, ion fans and ion air guns are good static eliminators. Their principle is to generate a large number of positive and negative ions on the static eliminator, and then blow these ions through the wind to the place with static electricity, and the static electricity will attract the opposite polarity. The ions in the product are neutralized, and the static electricity accumulated on the surface of the product or equipment can be neutralized and eliminated.
3. Use static eliminator
Use static eliminator sassafras to wash the surface of the instrument and the object, which can quickly eliminate the static electricity on the surface of the object. The antistatic agent uses grease as the raw material, and the main component is the quaternary ammonium salt. Its function is to make the surface of chemical fiber, rubber, plastic and other objects absorb moisture in the air and increase the conductivity.
4. Electrostatic shielding
The usual method is to use electrostatic shielding bags and anti-static turnover boxes as protection. Electrostatic sensitive components will be exposed to static electricity during storage or transportation. The electrostatic shielding method can weaken the influence of external static electricity on electronic components.
5. Control the environmental humidity
When the relative humidity of the air is above 65-70%, a very thin water film is often formed on the surface of the object. The water film can dissolve the CO2 in the air, so that the surface resistivity is greatly reduced, and the static charge is not easy to accumulate. If the relative humidity of the surrounding air drops to 40-50%, static electricity will not easily dissipate, and a high potential may be formed. The common method to increase the air humidity is to spray water mist into the air. Rotary fan sprayers are generally used. However, the machine is not explosion-proof and must be blown in from outside the wall.