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1947 - George A. Horton increases the focal length of light intensity tests and makes possible measurements from any angle

REVOLVING MIRROR SPEEDS TESTS OF LIGHT INTENSITY

CD 1963098 E&MP 25.037

Electric Lamps

Sunday, December 28, 1947

A new device to measure the light output of street luminaires includes the large mirror shown at left. The mirror can be moved in a giant circle to reflect the light of the football-shaped street light at right. Some 25 feet away, the reflected light is measured by a sensitive photocell.

Use of the mirror increases the focal length of these light intensity tests and makes possible measurements from any angle without moving the street light being tested.

At the control board in the background is George A. Horton, Westinghouse engineer in charge of the newly-remodeled photometric laboratory.


Original Caption by Science Service
Westinghouse



National Museum of American History

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