ANSI/IES LS-1-22, Lighting Science: Nomenclature and Definitions for Illuminating Engineering
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
- Spectral Parameters Used in Illumination Engineering
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- radiance
- radiant efficiency
- radiant energy density
- radiant energy, Q
- radiant exitance
- radiant exposure
- radiant exposure rate
- radiant fluence
- radiant fluence rate
- radiant flux areal density
- radiant flux density at a surface
- radiant flux maintenance
- radiant flux (radiant power)
- radiant intensity
- radiant sterisent
- radiator
- radiometry
- radiosity
- rail lights
- range lights
- rapid-start fluorescent lamp
- rated lamp life
- ray tracing
- Rayleigh scatter
- reaction time
- rear screen projector
- reciprocal color temperature
- reciprocity
- recoverable light loss factor
- redirecting surfaces and media
- reference ballast
- reference line
- reference standard
- reflectance factor, R
- reflectance, ρ (of a surface or medium)
- reflected direct luminaire
- reflected glare
- reflected radiation coefficient, RRC
- reflection
- reflectivity
- reflectometer
- reflector
- reflector lamp
- reflex reflector
- refraction
- refractor
- regions of the electromagnetic spectrum
- regressed
- regular (specular) reflectance
- regular (specular) reflection
- regulation (of voltage)
- relative contrast sensitivity, RCS
- relative luminosity
- relative luminosity factor
- remote control switch
- resolving power
- resultant color shift
- retina
- retinal burn
- retinal burn hazard function
- retinal ganglion cells
- retinal hazard region
- retro-reflector (reflex reflector)
- RGB color system
- rheostat
- rhythmic light
- ribbon filament lamp
- Risk Group 1 (low risk)
- Risk Group 2 (moderate risk)
- Risk Group 3 (high risk)
- risk group classification (of lamps)
- rods
- room cavity
- room cavity ratio, RCR
- room coefficient,* Kr
- room index*
- room ratio*
- room surface dirt depreciation, RSDD
- room utilization factor (utilance)
- roundel
- runway alignment indicator
- runway centerline lights
- runway edge lights
- runway-end identification lights
- runway exit lights
- runway lights
- runway threshold
- runway visibility
- runway visual range, RVR