Note 1 to entry: The range between 100 nm and 400 nm is commonly subdivided into:

• UV-A: 315 nm to 400 nm;
• UV-B: 280 nm to 315 nm;
• UV-C: 100 nm to 280 nm.

Note 2 to entry: A precise border between ultraviolet radiation and visible radiation cannot be defined, because visual sensation at wavelengths shorter than 400 nm is noted for very bright sources.

Note 3 to entry: In some applications the ultraviolet spectrum has also been divided into "far," "vacuum," and "near" ultraviolet; however, the borders necessarily vary with the application (e.g. in meteorology, optical design, photochemistry, and thermal physics).

Note 4 to entry: This entry was numbered 845-01-05 in IEC 60050-845:1987.

Note 5 to entry: This note applies to the French language only.