20 Terms
Contributors in Lighting
Lighting
maintained illuminance
Construction; Lighting
Refers to light levels of a space at other than initial or rated conditions. This terms considers light loss factors such as lamp lumen depreciation, luminaire dirt depreciation, and room surface ...
T12 lamp
Construction; Lighting
Industry standard for a fluorescent lamp that is 12 one-eighths (1 inches) in diameter. Other sizes are T10 (1 inches) and T8 (1 inch) lamps.
radio frequency interference (RFI)
Construction; Lighting
Interference to the radio frequency band caused by other high frequency equipment or devices in the immediate area. Fluorescent lighting systems generate RFI.
ultra violet (UV)
Construction; Lighting
Invisible radiation that is shorter in wavelength and higher in frequency than visible violet light (literally beyond the violet light).
louver
Construction; Lighting
Grid type of optical assembly used to control light distribution from a fixture. Can range from small-cell plastic to the large-cell anodized aluminum louvers used in parabolic fluorescent fixtures.
direct glare
Construction; Lighting
Glare produced by a direct view of light sources. Often the result of insufficiently shielded light sources.
high intensity discharge (HID)
Construction; Lighting
Generic term describing mercury vapor, metal halide, high pressure sodium, and (informally) low pressure sodium light sources and luminaires.
