IUumination Meter Records Changing Light
Values.--Rapid fluctuations in illumination intensity are accurately recorded by a new photoelectric light recorder introduced by the Weston Electrical Instrument Corp. Developed originally to chart the fast-changing light output of railway fuses, this new instrument also lends itself to many applications where wide variations in light intensity must be recorded faster than can be done by hand.
Though a new device, the W eston photoelectric light recorder utilizes prindples previously employed in other Weston and TAGliabue instruments. The sensing element, which can be placed wherever convenient, employs a "Photronic" photoelectric cell of the dry disk type made by Weston for more than 15 years. A built-in "Viscor" filter matches its color response to that of the human eye. Its "Celectray" recorder, of proved TAGliabue design, follows rapid changes without overshooting or hunting.
Full scale values of 20, 40 or 80 foot-candles are selected by a single switch. The recorder can also measure candlepower of any value by proper adjustment of distance from the light source. Descriptive literature giving technical details and specifications is available from the manufacturer.