Our customer is an armour solutions provider based in the UK. They were looking to use a fluorescent penetrant to inspect for cracks in aluminium oxide tiles used for armour protection.
The issue with aluminium oxide tiles is that they are semi-porous. A high-sensitivity penetrant would fill up all the surface pores and be difficult to remove.
We recommended ZYGLO® ZL-19, a level 1 sensitivity, water-washable fluorescent penetrant. ZL-19 allowed them to see specific defects that meant a tile had to be rejected, and to distinguish this from any general background indications caused by the structure of the tile surface.