A clear understanding on the concept of Double beam and Single beam optics is an absolute must for a spectroscopist. A common misconception is that in a double beam instrument two beams pass simultaneously through the sample cell and provide a sensitivity advantage over single beam systems. For that matter the more the number of beams passing through the sample cell better will be the sensitivity.
Today’s Lab Byte session will help dispel such misconceptions. In Double beam design one beam component passes through the sample cell and the other through the blank solvent taken in the reference cell. This arrangement helps compensate errors arising due to changes in any of the operational parameters such as power line fluctuations, stray light and solvent absorbance during absorbance observations which contributes to higher accuracy and precision of results.