What’s the Difference Between UVA-340 and UVB-313?

Both UVA-340 and UVB-313 emit UV lights, but they have different light emission spectrums.

• The luminescence spectrum of the UVA-340 tube ranges from 315nm to 400nm, which is mainly focused on wavelengths 340nm. UVA-340 tube is the optimum choice for simulation of UV in solar light during the noon of summer, which is also recommended in most UV tests.
• The emission spectrum of the UVB-313 tube is in the scope from 280 to 315nm, which is concentrated on wavelengths 313nm. It is much stronger than any spectrum existing in the sunlight on the earth, featuring  the maximization of accelerating the weathering during the test, which is beyond the intensity of spectrum existing in a real environment, with harm to specimens.