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A unit of luminance (photometric brightness), equal to 1/π candela per square foot, or to the uniform luminance of a perfectly diffusing surface emitting or reflecting light at the rate of 1 lumen per square foot; equal to approximately 3.42625 nit. Abbreviated ft-L. Also known as equivalent footcandle.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
1. A unit of luminance equal to ½ candela per sq ft.
2. The uniform luminance of a perfectly diffusing surface emitting or reflecting light at a rate of 1 lumen per sq ft.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.