Monday, October 29, 2012

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

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. 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 http://www.bmglabtech.com/technology/spectrometer.cfm/. BMG LABTECH instruments that have a spectrometer include: SPECTROstar Nano, Omega Series of readers, and the PHERAstar FS.