GB/T 20150-2023 Erythema reference action spectrum and standard erythema dose
1 Scope
This document specifies the erythema reference action spectrum, ser (λ), and the standard erythema dose (SED).
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
CIE S 017/E:2020, ILV: International Lighting Vocabulary, 2nd Edition
3 Terms and definitions
For the purposes of this document, the terms and definitions given in CIE S 017 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
——ISO Online browsing platform: available at https://www.iso.org/obp
——IEC Electropedia: available at http://www.electropedia.org/
3.1
erythema spectral weighting function
erythema action spectrum
ser (λ)
function representing the spectral dependence of the ability of ultraviolet radiation (3.6) to produce just perceptible actinic erythema in human skin
[SOURCE: CIE S 017/E, 17-26-065]
3.2
erythemal irradiance
Eer
effective irradiance with the spectral irradiance, Eλ, spectrally weighted with the erythema spectral weighting function, ser (λ), (3.1), where the erythema spectral weighting function ser (λ) is normalized to 1 at the maximum value
Note 1: This definition is based on the assumption that an action spectrum is adopted for the actinic effect considered, and that its maximum value is 1.
Note 2: It is essential to specify which action spectrum is used, as the unit is the same.
Note 3: The erythemal irradiance is expressed in watts per square metre (W·m−2 ).
[SOURCE: CIE S 017/E:2020, 17-26-067]
3.3
erythemal dose
erythemal radiant exposure
Her
time integral of erythemal irradiance (3.2) defined by the formula:
3.4
minimal erythema dose
MED
actinic dose, using the erythema spectral weighting function (3.1), that produces a just noticeable actinic erythema on a single individual’s previously unexposed skin
Note 1: The minimal erythema dose is a subjective measure based on the reddening of the skin; it depends on many variables, e.g. individual sensitivity to ultraviolet radiation (3.6), radiometric characteristics of the source, skin pigmentation, anatomic site, elapsed time between irradiation and observing the reddening (typical value: 24 h), etc. Since it varies with each individual, it should be reserved solely for observational studies
in humans and other animals.
Note 2: See also standard erythema dose (3.5).
Note 3: The minimal erythema dose is expressed in joules per square metre (J·m−2 ).
[SOURCE: CIE S 017/E:2020, 17-26-068]
3.5
standard erythema dose
SED
standardized unit of measure of erythemal radiation
Note 1: One standard erythema dose (1 SED) is equivalent to an erythemal radiant exposure of 100 J·m−2.
Note 2: See also minimal erythema dose (3.4).
[SOURCE: CIE S 017/E:2020, 17-26-069, modified.]
3.6
ultraviolet radiation; UV radiation
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, thermal physics).
[SOURCE: CIE S 017/E:2020, entry 17-26-008]
4 Concept of erythemal irradiance and dose
4.1 Erythemal irradiance
The erythemal irradiance, Eer , from a source of UV radiation is obtained by weighting the spectral irradiance of the radiation at wavelength λ (in nm) by the effectiveness of radiation of this wavelength to cause a minimal erythema and summing over all wavelengths present in the source spectrum. This can be expressed mathematically as shown in Formulae (1) and (2):
