The use of ultraviolet or fl uorescent dyes in an r-1234yf system is

The use of ultraviolet or fluorescent dyes in an r-1234yf system is for leak detection. By allowing to mix together with the refrigerant, a little amount of fluorescent dye in the A/C system outflows and gathers in all the sites having a leak. Checking the system with the use of flashlight with leak detection capability, the leaks will brightly glow, making it easy to see.