Radiation energy said to printing product surface unit area of total photon (and radiation intensity is arrival rate). In a designated light, radiation energy and curing speed is inversely proportional to the time of solidification is proportional. Radiant energy is radiation intensity of time accumulated, per square centimeter joule or millijoule said, (unfortunately, there is no relevant radiation intensity or spectral content change in radiation energy measurement information, it is only by exposure surface energy accumulation. Its significance lies in it is the only include the speed parameters and curing time parameter characteristics revealed.

　　2. UV radiation intensity

　　Radiation intensity is reaches the surface of the radiation power per unit area. Radiation intensity, per square centimeter watt or milliwatt to said. It with the lamp output power, efficiency, reflection system and to focus on the surface of different and different distance. Direct UV lamp in the high strength, peak focusing power reference for "peak radiation degree". Radiation intensity includes all relevant power supply power, efficiency, radiation output, reflectivity, focusing tube size and geometry shape factors. Because of UV curing materials can be the absorption characteristic to the light energy of surface than less surface. In these areas of the curing conditions may have significant different. Optical thickness thick material may reduce the efficiency of light, leading to material deep curing don't fully. In ink or coating, surface high radiation intensity will provide relatively high light energy. The depth of the curing more is radiation degree influence not long curing time (radiation). High radiation degree allowed to use less light initiator. Photon density increase increased the photon - light initiator collision, so as to compensate the light initiator concentration reduction. The thicker coating will be effective, because the surface of light initiator absorption and hinder the same wavelength reach deep light initiator molecules.