STADIUM CLASS DESIGNATIONS
- Class I – Facility with OVER 5,000 spectator capacity
- Class II – Facility with UNDER 5,000 spectator capacity
- Class III – Facility with SOME spectator capacity
- Class IV – Facility with NO spectator capacity
- Horizontal illuminance – a measure of the lumens per unit area on a horizontal surface. Normally it is measured three feet above the playing surface.
- Uniformity illuminance – a measure of the rate of change of illuminance expressed as a ratio between the illuminance level of adjacent measuring points on a uniform grid. The limit of uniformity varies with the speed of the ball.
- LUX – a measure of illuminance weighted to the spectral sensitivity of the human eye. It is defined as 1 lux = 1 lumen/square meter.
- FC – foot-candle. The official definition is 1 foot-candle = 10.764 lux; however, it is easiest to approximate at 1 foot-candle ≈ 10 lux.