Lighting Illuminance Uniformity Ratio
Avg/min, max/min, and U0 = min/avg from a grid of illuminance readings, against a target ratio. Readings 50/45/60/55/40 fc -> 1.25 avg/min, 1.50 max/min; a patchy 70/20/65/25/30 fails a 3:1 target the average hides. The IES RP for the space governs.
Formula and source
avg/min, max/min, U0 = min/avg over a grid of readings; pass if avg/min <= target and max/min <= target.
The IES illuminance uniformity ratios (avg/min, max/min, U0), by name.
Audience
This tile is built for electricians and the adjacent professions in the Electrical group. The interactive calculator runs entirely in your browser. No account, no fee, no advertising, no tracking.
Related tools
Posture
Rough Logic answers the math question the working professional asks on the job. The site is a calm, fast, ad-free, account-free, ever-free reference. It does not interpret code. It does not replace the licensed professional. It does not store your inputs. The Authority Having Jurisdiction governs all installations and inspections.