The IES defines illumination engineering terms in ANSI/IES LS-1-22, is available here online. You can search terms by their first letter using the categories listed in the Categories window, by the first letter of the term in the alphabetical list below, or by typing the term in the search window. You can find the Introduction material for LS-1-22 on these pages:
Copyright, Disclaimer, and American National Standards Statement
Foreword, Nomenclature Committee members, Introduction, and Scope
- table lamp
- Table T-1: Luminance Conversion Factors
- Table T-2: Standard Units, Symbols, and Defining Equations for Fundamental Photometric and Radiometric Quantities*
- Table T-3: Illuminance Conversion Factors
- Table T-4: Definitive Values of the Special Luminous Efficiency Function for Photopic Vision V(λ)
- Table T-5A: Color-Matching Functions and Chromaticity Coordinates of CIE 1931 Standard Colorimetric Observer
- Table T-5B: Color-Matching Functions and Chromaticity Coordinates of CIE 1964 Supplementary Standard Colorimetric Observer
- Table T-6: Relative Spectral Power Distribution of CIE Illuminant “C”
- Table T-7: Scotopic Spectral Luminous Efficiency Values, V′(λ) (Unity at Wavelength of Maximum Luminous Efficacy)
- Table T-8: Tentative Bactericidal Efficiency of Ultraviolet Radiation
- Table T-9: CIE 1988 Modified Two-Degree Spectral Luminous Efficiency Function for Photopic Vision
- tail lamp
- talbot (T)
- tanning lamp
- task-ambient lighting
- task lighting
- task tuning
- taxi-channel lights
- taxi light
- taxiway centerline lights
- taxiway-edge lights
- taxiway holding-post light
- taxiway lights
- temperature radiator
- tenner (or ten-K, or 10-K)
- threshold
- threshold increment (TI)
- threshold lights
- throw
- time switch
- tint
- tonal light
- tone
- top hat
- top light
- toplighting
- torchère (or torchiere)
- tormentor lighting
- total emissivity
- total internal reflection (TIR)
- total (solar) radiation
- touchdown zone lights
- track lighting
- traffic beams
- train
- transient adaptation factor, TAF
- transillumination
- transition lighting
- translucent medium
- transmission
- transmissometer
- transmittance (of a medium)
- transparent medium
- transverse roadway line, TRL
- trichromacy
- tristimulus values of a light, X,Y,Z
- troffer
- troland
- Troxler effect
- tube
- tunable lighting
- tunable white
- tungsten-halogen lamp
- turn-signal operating unit
- two-K
- twofer