What is the difference between a spectrometer and a monochromator for absorbance measurements?

October 29, 2012

A spectrometer incorporates a highly efficient optical grating and a solid state array detector that allows the measurement of light intensity throughout the entire UV and visible parts of the spectrum.

Image of Dr EJ Dell
Dr EJ Dell
PhD, Sales Manager Northwest
BMG LABTECH USA

Similar to a monochromator, but much faster, the spectrometer allows you to capture the whole UV/Vis spectrum (220-1000 nm) of a sample within one second per well – no scanning is needed.

 

In practical terms, a monochromator only captures one measurement in the UV-Visible spectrum at a particular wavelength or a particular bandwidth, and therefore gives only one value. Whereas a spectrometer captures the entire UV-Visible spectrum in the same amount of time, giving values at every wavelength.

 

Here is a graphical representation of this – notice all of the information that is lost if a monochromator is used:

 

Find out more about this technology in an article on Genetic and Engineering News:


Microplate Reader Absorbance Assays - New Tools Bridge Gap between Single and Multiple Sample Absorbance Instruments.


For more information on the UV/Vis absorbance spectrometer technology used in BMG LABTECH's instruments, visit our website. BMG LABTECH instruments that have a spectrometer include: SPECTROstar Nano, Omega Series of readers, and the PHERAstar FS.

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