Spectrometer

A device which measures light wavelengths from a specimen.

Description

Spectrometers use a diffraction grating or a prism to divide the light from the specimen into its spectrum. Usually this is accomplished by measuring wavelength bands. The width of the band determines the spectrometer's ability to discern spectral details. Bandwidths of 20, 10, 5, 4, 2 and 1 nm are common measuring intervals.

Some instruments measure with large bandwidths then interpolate to smaller reporting intervals, for instance the X-Rite SP-68 measures at 20 nm bandwidths then reports at 10 nm intervals. This is called undersampling. More accurate instruments oversample the spectrum by measuring at small bandwidth intervals but report at larger bandwidths. An example of this is the Eye-One, which measures at 3.5 nm intervals but reports at 10 nm bandwidths.

Copyright ©2007 Robin D. Myers, all rights reserved.