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 400nm to 700nm.
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 400nm to about 575nm. This includes the violet, indigo, blue, green and yellow color portions of the spectrum.
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 575nm to 700nm, the optical transmittance increases to about 75% at 700nm, and then further increases to about 85% at 800nm in the infrared region.
Beyond the shorter wavelength end of the visible light spectrum, from 400nm to about 250nm, amberized NMR tubes block virtually all incident ultraviolet light. In addition, beginning at about 360nm, the intrinsic opacity of glass to ultraviolet light increases, becoming completely opaque at 250nm and beyond, to the end of the UV region at 100nm.