1. Immerse the workpiece in a beaker filled with 3500P fluorescent penetrant, take it out immediately, and leave it for 10 minutes. Since there will be sagging during the placement process, use a dropper to add penetrant on the way.
![1-20111Q4431E13.jpg](/../../upload/image/20220219/6378085883654423437961883.jpg)
2. Rinse the workpiece with tap water for about 20 seconds to remove excess penetrant from the surface.
![1-20111Q44501Y3.jpg](/../../upload/image/20220219/6378085886541922348240408.jpg)
3. Use 3500R special emulsifier (1:4 dilution), drop the dropper on the surface of the workpiece, observe the emulsification state under a black light, rinse it off with tap water after 1 minute after the emulsification is complete (there is no fluorescent background on the surface under the black light, emulsification agent residue), shake off the surface water droplets.
![1-20111Q4464M57.jpg](/../../upload/image/20220219/6378085890446613959511596.jpg)
Drop emulsifier
![1-20111Q44TBP.jpg](/../../upload/image/20220219/6378085895601299314630631.jpg)
Washed
4. Dry the residual water on the surface, use a small brush to apply a dry powder developer on the surface, observe it under a black light after 10 minutes, and the result shows no natural defects.
![1-20111Q45059564.jpg](/../../upload/image/20220219/6378085900138799345068313.jpg)
Drying
![1-20111Q45239235.jpg](/../../upload/image/20220219/6378085901779429184255654.jpg)
Apply developer powder