PURPOSE: Show how a spectrophotometer works.

DESCRIPTION: A bright point source of light with condenser lens and iris is incident on a slit. The slit is imaged by a 20 cm focal length convex lens onto a plane near the end of the rotating extension arm attached to the main optical rail. A spectrum is obtained by inserting a prism at the center of rotation of the rotating arm. A radiometer is attached to the rotating arm so that it rotates through the spectrum, displaying the intensity of the light on a slave overhead projector meter.

Various filters (or other optical gizzits) can be inserted into the beam and their transmission spectra read using this spectrophotometer.



EQUIPMENT: Bright point light source with condenser lens and iris, slit, 20cm focal length convex lens, prism, and radiometer with slave overhead projector meter; red, green, and blue filters.

SETUP TIME: 5 min.

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