Beams specific light wavelength (colour) through sample
Measures light absorbed
Assess colour intensity
Provides quantitative strength measure
Colour filters control wavelength emitted
Will contrast with solution colour
Must be calibrated before measurements
Place blank into colorimeter
Should read 0 (no light is absorbed)
Repeated periodically whilst measuring to ensure absorbance still 0
Plot results on calibration or standard curve
Absorbance against known concentrations
Unknown concentrations can be determined from graph
