167810 ⎘
Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light; Systems in which incident light is modified in accordance with the properties of the material investigated; Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands; Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry; Atomic absorption analysis Commutating sources, e.g. line source/broad source, chopping for comparison of broad/narrow regimes