Uranine tracer dye
Standard fluorescent dye for leak detections and flow path testing
Uranine is the most intensely fluorescing tracer dye and easily visible to the naked eye, which is why it is often used for marking waters. Greatly diluted, the highly water-soluble uranine powder is toxicologically harmless and ideally suited for all leak detections and tightness tests requiring the dyed water to penetrate capillaries. Therefore the leak becomes apparent with a clear time lag to the dye addition. Even tiny leaks can be rendered visible using a UV lamp.
The pure uranine powder as well as highly concentrated solutions in water have a dark red colour. They do not fluoresce. When further diluted, however, the uranine will dye the water in a yellow-green to green fluorescent colour, depending on the degree of dilution. This effect becomes clearly visible when the solution is irradiated with a 365 nm UV lamp such as the UV-TrackMaster.
Note: Uranine must not be used as food colourant!