GB/T 2900.65-2023 Electrotechnical terminology - Lighting
1 Scope
This document defines terms and definitions related to lighting and basic general optical radiation, human visual and non-visual effects, measurements, products, optical properties of materials, and applications such as lighting, therapy, visual signalling and imaging technology.
This document gives the general terminology used in lighting, as well as general terms pertaining to specific applications and associated technologies.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
845-21 Radiation, quantities and units
845-21-001
electromagnetic radiation,
See IEV 702-02-07
Note 1: This entry was numbered 845-01-01 in IEC 60050-845:1987.
Note 2: The IEV 702-02-07 website at: https://www.electropedia.org/iev/iev.nsf/display?openform&ievref=702-02-07.
845-21-002
optical radiation
electromagnetic radiation at wavelengths between the region of transition to X-rays (λ ≈ 1 nm) and the region of transition to radio waves (λ ≈ 1 mm)
Note: This entry was numbered 845-01-02 in IEC 60050-845:1987.
845-21-003
visible radiation
optical radiation capable of causing a visual sensation directly
Note 1: There are no precise limits for the spectral range of visible radiation since they depend upon the amount of radiant flux reaching the retina and the responsivity of the observer. The lower limit is generally taken between 360 nm and 400 nm and the upper limit between 760 nm and 830 nm.
Note 2: This entry was numbered 845-01-03 in IEC 60050-845:1987.
845-21-004
infrared radiation; IR radiation; IRR
optical radiation for which the wavelengths are longer than those for visible radiation
Note 1: For infrared radiation, the range between 780 nm and 1 mm is commonly subdivided into:
——IR-A: 780 nm to 1400 nm, or 0.78 μm to 1.4 μm;
——IR-B: 1.4 μm to 3.0 μm;
——IR-C: 3 μm to 1 mm.
Note 2: A precise border between "visible radiation" and "infrared radiation" cannot be defined because visual sensation at wavelengths greater than 780 nm can be experienced.
Note 3: In some applications the infrared spectrum has also been divided into "near," "middle," and "far" infrared; however, the borders necessarily vary with the application.
Note 4: This entry was numbered 845-01-04 in IEC 60050-845:1987
845-21-005
IR-A
infrared radiation covering the range from 780 nm (0.78 μm) to 1400 nm (1.4 μm)
845-21-006
IR-B
infrared radiation covering the range from 1.4 μm to 3.0 μm
845-21-007
IR-C
infrared radiation covering the range from 3 μm to 1 mm
845-21-008
ultraviolet radiation; UV radiation; UVR
optical radiation for which the wavelengths are shorter than those for visible radiation
Note 1: The range between 100 nm and 400 nm is commonly subdivided into:
——UV-A: 315 nm to 400 nm;
——UV-B: 280 nm to 315 nm;
——UV-C: 100 nm to 280 nm.
Note 2: A precise border between ultraviolet radiation and visible radiation cannot be defined, because visual sensation at wavelengths shorter than 400 nm is noted for very bright sources.
Note 3: In some applications the ultraviolet spectrum has also been divided into "far," "vacuum," and "near" ultraviolet; however, the borders necessarily vary with the application (e.g. in meteorology, optical design, photochemistry, and thermal physics).
Note 4: This entry was numbered 845-01-04 in IEC 60050-845:1987.
845-21-009
UV-A
ultraviolet radiation covering the range from 315 nm to 400 nm
845-21-010
UV-B
ultraviolet radiation covering the range from 280 nm to 315 nm
845-21-011
UV-C
ultraviolet radiation covering the range from 100 nm to 280 nm
845-21-012
light, noun
radiation that is considered from the point of view of its ability to excite the visual system
Note 1: The term "light" is sometimes used for optical radiation extending outside the visible range, but this usage is not recommended.
Note 2: This entry was numbered 845-01-06 in IEC 60050-845:1987.
845-21-013
light, noun
radiation within the spectral range of visible radiation
Note: Sometimes, the term "light" is also used in physics as a synonym of optical radiation, covering the spectral range from 100 nm to 1 mm and sometimes even covering the X-ray spectral range. This misuse of the term ‘'light'' should be avoided.
845-21-014
monochromatic radiation
radiation characterized by a single frequency or a single wavelength
Note 1: If the wavelength is used to characterize a monochromatic radiation, the medium has to be stated.
Note 2: In practice, monochromatic radiation is radiation of a very small range of frequencies or wavelengths that can be described by stating a single frequency or wavelength.
Note 3: This entry was numbered 845-01-07 in IEC 60050-845:1987.
Note 4: For the definition of frequency, see IEV103-06-02 (https://www.electropedia.org/iev/iev.nsf/display?openform&ievref=103-06-02).
845-21-015
spectrum
display or specification of the monochromatic components of the radiation considered
Note 1: There are line spectra, continuous spectra, and spectra exhibiting both these characteristics.
Note 2: The term "spectrum" is also used for spectral efficiencies (excitation spectrum, action spectrum).
Note 3: This entry was numbered 845-01-08 in IEC 60050-845:1987.
845-21-016
spectral line
monochromatic radiation emitted or absorbed in a transition between two energy levels
Note 1: A spectral line is often observed as a sharp feature in a spectrum.
Note 2: This entry was numbered 845-01-09 in IEC 60050-845:1987.
845-21-017
polarized radiation
radiation whose electromagnetic field, which is transversal, is oriented in defined directions
Note 1: The polarization can be linear, elliptic or circular.
Note 2: This entry was numbered 845-01-10 in IEC 60050-845:1987.
845-21-018
circularly polarized radiation
radiation in which the electric field vector is of constant amplitude and rotates about the direction of propagation at a rate equal to the radiation frequency
Note: Circularly polarized radiation is described as right-handed (or left-handed) if the rotation of the electric field vector is clockwise (or anticlockwise) as viewed by an observer receiving the radiation.
845-21-019
elliptically polarized radiation
electromagnetic radiation in which the electric field vector rotates at the radiation frequency, but varies in magnitude at a rate equal to twice the radiation frequency with the terminal point of the electric field vector describing an ellipse
Note: Elliptically polarized radiation is described as right-handed (or left-handed) if the rotation of the electric field vector is clockwise (or anticlockwise) as viewed by an observer receiving the radiation.
845-21-020
linearly polarized radiation
radiation in which the electric field vector is at a fixed azimuth, i.e. it is confined to a plane containing the direction of propagation of the radiation
845-21-021
unpolarized radiation
radiation that exhibits no preferential directional property in a plane normal to the direction of propagation of the radiation, the direction and phase of the electric field vector being randomly distributed
Note: A beam of unpolarized radiation can be regarded as being composed of two components of equal amplitude but with orthogonal states of polarization, the two components being unrelated in phase.
