How does the monochromator in my UV detector work?

White light is a mixture of electromagnetic waves with different wavelengths. A monochromator is used to separate a single wavelength from an incoming beam of light. After passing the entrance slit of the monochromator the light is expanded into its wavelengths. This can be done by a dispersive element like a prism, or, like for KNAUER monochromators, by an optical grating, which diffracts the incoming light. With another slit at the outlet of the polychromator only a small wavelength range of the expanded light beam leaves the polychromator and enters the flow cell. As the outlet slit is fixed in its position it is necessary to rotate the grating in the monochromator to choose the desired wavelength for the HPLC analysis.

We separate molecules and unite people.

Based in Berlin, KNAUER is a medium-sized company that has been serving the sciences since 1962. We are a developer and manufacturer of scientific instruments of superior quality for liquid chromatography (LC), liquid dosing and other laboratory tasks. The product range includes systems, engineering solutions and components for:

Analytical HPLC / UHPLC
Preparative HPLC
Fast protein liquid chromatography (FPLC)
Multi-column Chromatography / SMB
High-pressure dosing solutions
Lipid nanoparticle (LNP) production and research

We are an established partner in science. Today and in the future.​​​​​​

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