Zyglo® ZL-4C contains no petroleum base solvents and fluoresces a greenish-yellow color under ultraviolet radiation of 365 nm. Use of an ultraviolet light source with a peak wavelength of 365 nanometers, such as the Magnaflux ZB-100F fan-cooled black light, is recommended.
The use of aqueous developers is not recommended with ZL-4C as they tend to wash the penetrant out of the discontinuities. Dry powder developer (ZP-4B Dry Powder Developer) is applied after the test surface has been dried.
ASME B & PV Code Sec V, ASTM E165
Automobile Parts, Off-Road Equipment, Farm Equipment, Welds, Castings, Forgings, Leak Testing, Pressure Vessels, Aircraft, Marine, Construction, Maintenance, Petroleum Pipelines, Power Plant Inspections, General Metalwork.