Fluorescent UV lamps are typically categorized as UVA or UVB lamps based on the
wavelength of the UV output.
• QUV-A 340 Testing: Simulates the effects of real sunlight with fluorescent ultraviolet UVA-340 lamps, which
provide excellent simulation of sunlight in the critical short wavelength region from 365 nm down to the solar cutoff of 295 nm. This type of UV lamp is recommended for QUV testing by the global ASTM G154 Standard. UVA340 lamps are especially useful for comparison tests of different coating formulations.
• QUV-B 313 Testing: To speed up acceleration testing, UVB-313 lamps are used. They produce not only the shortest
ultraviolet rays that the sun emits, they also emit unnaturally, short-wavelengths below what is found on the earth’s
surface, which can produce anomalous results. This type of UVB light can initiate chemical reactions to occur in the
coating that would normally not be possible under natural, real-world sunlight exposures. This testing has been
proven to have poor correlation to natural weathering. It can cause failures in good-quality coatings that would not
occur in natural sunlight and false positives in coatings that contain low-quality pigmentation https://www.valsparcoilextrusion.com/opencms/export/sites/co...

(2000) Ultraviolet exposure (UV-B) perturbations caused by the quasi-biennial oscillations (QBO) in ozone. J Geophys Res 105:29189–29193 Hermansdörfer I, ... https://books.google.com.ua/books?id=_lCFQkM2i_4C&pg=PA146&l...