Teaching Labs has six Jenway 7415 single-beam photometers. These are best used for photometric or kinetic measurements, although they are also capable of recording scanning spectra (but you are advised to use dual beam instruments instead).

Scanning Mode

The Jenway 7415 photometers can record scanning spectra, however better results can be obtained from a dual-beam instrument. Scanning spectra are often recorded in order to determine the wavelength of maximum absorbance (λmax) which can then be used for photometric or kinetic measurements, or to provide characterisation data for a compound.

Photometric Mode

Photometric mode is used to record absorbance values at a given wavelength. As absorbance is related to concentration through the Beer-Lambert law (A =  ε c l), the concentration of a solution can be determined through the use of standards and recording a set of measurements in photometric mode.

Kinetics Mode

Kinetic mode is used to record the absorbance at a given wavelength as a function of time. This allows the study of reaction rates for reactions which have starting material(s) or product(s) having an absorbance within the range of the spectrophotometer.