NORELL® amberized glass NMR tubes offer photosensitive materials a considerable degree of protection from visible and ultraviolet radiation, compared to clear, non-amberized, glass NMR tubes, which typically have an optical transmittance of about 95% throughout the visible light spectrum, from 400 nm to 700 nm.

Amberized NMR tubes, however, have virtually no optical transmittance, blocking almost all incident light throughout most of the visible region of the spectrum, from about 400 nm to about 575 nm. This includes the violet, indigo, blue, green and yellow color portions of the spectrum.
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Only upon entering the orange and red color regions of the visible spectrum does the optical transmittance of amberized NMR tubes begin to rise. From near 575 nm to 700 nm, the optical transmittance increases to about 75% at 700 nm, and then further increases to about 85% at 800 nm in the infrared region.
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Beyond the shorter wavelength end of the visible light spectrum, from 400 nm to about 250 nm, amberized NMR tubes block virtually all incident ultraviolet light. In addition, beginning at about 360 nm, the intrinsic opacity of glass to ultraviolet light increases, becoming completely opaque at 250 nm and beyond, to the end of the UV region at 100 nm.