[2.15] For convenience of reference, the electromagnetic spectrum is arbitrarily divided as follows:
| Vacuum ultraviolet | |
| Extreme ultraviolet | 10 to 100 nm |
| Far ultraviolet | 100 to 200 nm |
| Middle ultraviolet | 200 to 300 nm |
| Near ultraviolet | 300 to 400 nm |
| Visible | 380 to 770 nm |
| Near (short wavelength) infrared | 770 to 1,400 nm |
| Intermediate infrared | 1,400 to 5,000 nm |
| Far (long wavelength) infrared | 5,000 to 1,000,000 nm |
Note: The spectral limits indicated above have been chosen as a matter of practical convenience. There is a gradual transition from region to region without sharp delineation. Also, the division of the spectrum is not unique. In various fields of science, the classifications may differ due to the phenomena of interest.
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