Control Panel Cooling units Technical Information
3-8. Relationship between static electricity and humidity
The higher the absolute/relative humidity, the faster static electricity disappears (scatters).
A study of the relationship between static electricity and humidity shows that the higher the absolute humidity and the higher the relative humidity, the faster the static electricity scatters (dissolves).
This is thought to be due to the fact that high humidity increases the electrical conductivity of the surface of the material, accelerating the charge leakage speed.
The higher the absolute humidity, the faster the static electricity disappears.
The vertical axis (y) in the lower graph is the scattering time (time constant), and the horizontal axis is the absolute humidity.
The scattering time can be regarded as the time for static electricity to disappear, and the higher the absolute humidity, the less likely it is to be charged. Therefore it can be said that the degree of difficulty in accumulating static electricity relative to the degree of increase in humidity is very large.
*Absolute humidity … Weight of water vapor contained in 1㎥ of air
*The above is a graph of the results of measuring the potential by fixing a potential system probe 5 cm from the surface of the charged Japanese paper.
At the same absolute humidity, lowering the temperature eliminates the static electricity in a short time
It is known that γ (scattering time) = R (electrical resistance) x C (capacitance). As shown in the graph below, R (electrical resistance) in this case decreases exponentially as the relative humidity increases.
This means that as the relative humidity increases, the scattering time decreases significantly.
Even if the absolute humidity (the weight of water vapor contained in 1㎥ of air) is the same, the relative humidity rises when the temperature drops, so static electricity scatters in a short time.
*Relative humidity … The ratio of the amount of water vapor contained at that time to the saturated water vapor amount of unit volume air at a certain temperature
Relationship between electrical resistance and discharge time of Japanese paper
When the electrical resistance is 1/100, the discharge time is also 1/100.
| R:Electrical resistance(Ω) | Discharge time(s) |
|---|---|
| 1011 | 50 |
| 1010 | 5 |
| 109 | 0.5 |
*Static discharge time calculated when electrical resistance changes according to Graph 2 under the conditions of Graph 1.
Previous item: 3-7. Basics of static electricity
Next item: 3-9. Enthalpy
We're here to give you quick answers to your questions.