1. Environmental control
The testing environment should maintain a light intensity within the range of 20-50Lux to avoid external light interference. The light source inside the pinhole box should be stable (1000-1500Lux) to ensure even distribution of light. The recommended ambient temperature is 15-50 ℃ and humidity is ≤ 80%.
2. Sample preparation
The sample size should be ≥ 400mm × 250mm. If the width is insufficient, the roll width should be taken, and the surface should be flat without creases or mechanical damage.
Remove the wrinkled outer layer of the aluminum foil roll to avoid detection errors.
3. Operating standards
When observing, the distance from the sample should be about 0.5 meters, and the visual acuity (or corrected visual acuity) should be ≥ 5.0, ignoring pinholes with a diameter of<0.02mm.
Aluminum foil for power capacitors is recommended to use a 25.4mm × 25.4mm inspection frame for moving counting.
4. Instrument calibration and maintenance
Regularly calibrate the light source intensity (such as 30W fluorescent lamps) and microscope magnification (10-20 times).
Check the sealing of the needle hole box to prevent light leakage from affecting the detection results.
5. Standard compliance
It is necessary to strictly follow standards such as GB/T 22638.2-2016 and YBB00152002-2015 to ensure that the test results meet the needle hole requirements of medicinal aluminum foil (such as no pinholes with a diameter greater than 0.3mm).
6. Safety and Records
Be careful to prevent electric shock when using a 220V power supply, and the equipment should be grounded.
Record the number, size, and distribution of pinholes for quality traceability.