Simple colorimeters such as shown here are used to measure the amount of light transmitted through a solution. There are numerous departmental B&L Spectronic 20 and Spec20's which are used in a variety of teaching laboratories. They are also useful for routine analysis in a research environment. A few of the Spectronic 20 DUV can also make measurement in the ultraviolet region. The Instrument Laboratory (building 55 room 109A) has several diode array spectrometer (HP 8452A) in the biochemistry teaching laboratory and in 109A for the newest diode array, Agilent 8453. The Varian Cary 100 UV/VIS spectrophotometer is located in W186.
Quality printed graphs of UV-VIS spectra are made by transfer of H-P 8452A data to a 3 1/2" floppy disk and importing the spectra into ACD software. A similar procedure is used for FTIR spectra.
Many procedures such as for a spectrophotometric apply Beer-Lambert law to determine concentrations of an analyte.
The simple spectrophotometer principle is illustrated by the following sketch.
The Klett-Summerson Colorimeter
