Simple detection method for ion fan
Electrostatic voltmeter method
Use nylon cloth or plastic to rub against the surface of the tested anti-static equipment, and use a low-cost and easy-to-use electrostatic voltmeter to measure its surface potential. If the electrification is very low by a few hundred volts and decreases quickly or the indicator of the electrostatic meter is almost 0, The performance is better; if the electrification voltage is high, such as several thousand volts or tens of thousands volts, and it can hardly be reduced for a long time (a few seconds or longer), the anti-static performance is poor.
The calibration method of the technical indicators of the ion blower is to calibrate the ion blower with an electrostatic charge analyzer according to the technical requirements of the ion blower.
Pay attention to when calibrating:
1. The plate electrode cannot be in contact with any other objects.
2. The center of the plate electrode is aligned with the test position, and the normal line is parallel to the center line.
3. There is no other interfering air flow around.
4. There are no obstacles that hinder the airflow in the direction of the airflow, and no reflective surfaces that reflect the airflow, such as desktops, walls, etc.
5. The ambient temperature is 20±5℃, and the relative humidity is less than 50%
6. Perform two tests of positive and negative decay at each position.
When the measured electrostatic decay time is less than the technical index requirements, the product is qualified. Otherwise, a conclusion of unqualified shall be drawn.
However, when in use, if the actual use distance is relatively short and can meet the requirements of the maximum electrostatic charging rate of the controlled object, you can continue to use it according to the calibration data. For example, the maximum electrification rate of the controlled object is estimated to be less than 3.18x108A/m2, and the ion fan can be used in a position where the electrostatic decay time is less than 10 seconds.
At present, as an effective active static control device, ion fans are widely used in the field of electronic product production. Its quality directly affects the quality of the entire batch of electronic products, so it is of great significance to calibrate ion fans regularly. However, there is no standard basis for calibration and verification of ion fans in my country. The "electrostatic neutralization rate" index proposed in this article can intuitively reflect the technical performance of the ion fan, and is more scientific than the traditional electrostatic decay time index, and it is easy for users to understand. However, it is more complicated to directly measure the "electrostatic neutralization rate", and there is no product yet. The electrostatic charge analyzer can directly measure the decay time of static electricity. It is a common instrument for measuring ion fans and can also be used to calibrate ion fans. We have done a lot of experiments with ME-268A and 3M711 static charge analyzer.