Spectrophotometers XD 7000 VIS and XD 7500 UV-VIS UV-VIS and VIS spectrophotometers with dual beam optics. The instruments benefit from a barcode test recognition system over 150 pre-programmed analytical methods and automatic cuvette detection. Analytical quality assurance procedures include checks of the photometer the total system (including methods) and sample matrix effects. Further functions of the spectrophotometers include measurement of transmission and absorbance scanning of spectra kinetics analysis and creation of user-defined methods.