Editing Spectroradiometer (section)

=== Monochromator ===
{{main|monochromator}}

[[Image:Czerny-Turner_Monochromator.svg|thumb|200px|Diagram of a Czerny-Turner monochromator.]]

To perform spectral analysis of a source, monochromatic light at every wavelength would be needed to create a spectrum response of the illuminant. A monochromator is used to sample wavelengths from the source and essentially produce a monochromatic signal. It is essentially a variable filter, selectively separating and transmitting a specific wavelength or band of wavelengths from the full spectrum of measured light and excluding any light that falls outside that region.<ref name=AAS>American Astronomical Society. "Study Notes: AAS Monochromator." Study Notes: AAS Monochromator. N.p., n.d. Web. 2013. <{{cite web |url=http://toolboxes.flexiblelearning.net.au/demosites/series5/508/Laboratory/StudyNotes/snAASMonochrom.htm |title=Study Notes: AAS Monochromator |access-date=2013-12-11 |url-status=dead |archive-url=https://archive.today/20131211054338/http://toolboxes.flexiblelearning.net.au/demosites/series5/508/Laboratory/StudyNotes/snAASMonochrom.htm |archive-date=2013-12-11 }}>.</ref>

A typical monochromator achieves this through the use of entrance and exit slits, collimating and focus optics, and a wavelength-dispersing element such as a diffraction grating or prism.<ref name=Schnedier/> Modern monochromators are manufactured with diffraction gratings, and diffraction gratings are used almost exclusively in spectroradiometric applications. Diffraction gratings are preferable due to their versatility, low attenuation, extensive wavelength range, lower cost, and more constant dispersion.<ref name=AAS/> Single or double monochromators can be used depending on application, with double monochromators generally providing more precision due to the additional dispersion and baffling between gratings.<ref name=Bentham/>