A Basic SpectrophotometerOnline version Identify the parts of a basic spectrophotometer. by Heather Holmes 1 This component emits visible light. 2 This is an occluding or collimating tube. 3 These lenses collimate light (make the rays parallel). 4 This pivot allows the grating to rotate. 5 This disperses light into its component wavelengths. 6 A small band of light exits the monochromator here. 7 Sample Holder 8 Detector