Accession Number: 2011.ph.467
Painted black rectangular box with open sides. Detachable top with viewer/eye piece. Metal rod protruding from rectangle. Interior consists of two separate mirrored chambers separated by a paper covering with a small oblong-shaped grease stain.
Alternative Name: Grease spot photometer
Primary Materials: Painted metal, glass mirror, paper
Height = 27 cm, Width = 22 cm, Length = 13 cm
This instrument is used to visually compare the luminosity of two light sources. By looking through the hole the user can see, by means of the mirrors, the paper containing a grease spot from opposite sides. Placing a light source on one side of the instrument illuminates the paper and its grease spot. By placing the photometer between two light sources and comparing the relative brightness of the grease spots, the viewer can judge the relative luminosity of the two sources.
Good. Some wear on bottom of rod. Some subtle scratches from wear on painted metal. Paper inside is slightly ripped.
Associated Instruments: 2009.ph.149, 2011.ph.466
Date of Manufacture:
Acquired from Physics department, University of Toronto.