VII. Appendix

VII.1. Relevant quantities, their symbols and units

Quantity Symbol Unit(s)
Wavelength λ 1 nanometer = 1 nm = 10-9 m
1 Ångstrøm = 1 Å = 10-10 m
Power P 1 Watt = 1 W
Solid angle 1 steradian = 1 sr
Radiant power or radiant flux Φe 1 Watt = 1 W
Radiant intensity Ie 1 W sr-1
Radiance Le 1 W sr-1 m-2
Irradiance Ee 1 W m-2

Radiant exitance

EeMe 1 W m-2 1 W m
Luminous flux Φv 1 lumen = 1 lm
photopic: 1 lm corresponds to Φe = 1/683 W at λm = 555 nm
scotopic: 1 lm corresponds to Φe = 1/1700 W at λ’m = 507 nm
Luminous intensity Iv 1 candela = 1 cd = 1 lm / sr
Luminance Lv 1 lm sr-1 m-2 = 1 cd m-2 = 1 nit
1 stilb = 1 sb = 1 cd m
-2 1 apostilb = 1 asb = 1/π cd m-2
1 lambert = 1 L = 104/π cd m-2
1 footlambert = 1 fl = 3.426 cd m-2
Illuminance Ev 1 lux = 1 lx = 1 lm m-2
1 phot = 1 ph = 104 lx
1 footcandle = 1 fc = 1 lm ft
-2 = 10.764 lx
Luminous exitance EeMv 1 W m-2 -21 lm m
Spectral radiant power Φλ(λ) 1 W nm-1
Spectral radiant intensity Iλ(λ) 1 W sr-1 nm-1
Spectral radiance Lλ(λ) 1 W sr-1 m-2 nm-1
Spectral irradiance Eλ(λ) 1 W m-2 nm-1
Spectral radiant exitance Ee Mλ(λ) 1 W m-2 nm-1

Table VII.IV. Units in italic are not SI units, not consistent with CIE regulations and should not be used !

VII.2. Summary of radiometric and photometric quantities

Quantification of electromagnetic radiation ... Radiometric
Spectral quantity Photometric quantity quantity
depends on
... emitted by a source intotal radiant power
spectral radiant power
W nm-1
luminous flux
lm (lumen)
... emitted in a certain direction radiant intensity
W sr-1
spectral radiant intensity Iλ(λ)
W sr-1 nm-1
luminous intensity
lm / sr = cd
... emitted by a location on a surface radiant exitance
W m-2
spectral radiant exitance
W m-2 nm-1
luminous exitance
lm m
position on source’s surface
... emitted by a location on a surface in a certaindirection radiance
W sr-1 m-2
spectral radiance
W sr-1 m-2 nm-1
lm sr-1 m-2 = cd m-2
position on source’s surface and direction
... impinging upon a surface irradiance
W m-2
spectral irradiance
W m-2 nm-1
lm m-2 = lx
position on irradiated surface

Table VII.V – Radiometric and photometric quantities

Radiometric quantities:
In the following relations, X has to be replaced by one of the symbols Φ, I, L or E:



with λ1 and λ2 denoting the lower and the upper limit of the respective wavelength range (for instance, UVA)

Photometric quantities:
In the following relations, X has to be replaced by one of the symbols Φ, I, L or E:

Photopic vision: with Km = 683 lm / W

Scotopic vision: with K’m = 1700 lm / W

Basic integral relations between radiometric and photometric quantities:
In the following, x has to be replaced either by e (denoting radiometric quantities) or v (denoting photometric quantities).

VII.3. Sources and references for figures
Fig. II.1:
Fig. II.3:
Fig. II.5: adapted from
Fig.II.6: adapted from,,sid9_gci528813,00.html
Fig. II.11:
Fig. II.13: adapted from
Fig. II.16:
Fig. II.17:
Fig. II.19:
Fig. II.22:
Fig. VI.1:
Fig. VI.11:
Fig. VI.12:
Fig. VI.22:
Fig. VI.23:

VII.4. Most relevant CIE- DIN- and ISO-publications and regulations

VII.4.a. DIN Publications

DIN 4512-8
, Ausgabe:1993-01 Photographische Sensitometrie; Bestimmung der optischen Dichte; Geometrische Bedingungen für Messungen bei Transmission
DIN 4512-9, Ausgabe:1993-01 Photographische Sensitometrie; Bestimmung der optischen Dichte; Spektrale Bedingungen
DIN 5030-2, Ausgabe:1982-09 Spektrale Strahlungsmessung; Strahler für spektrale Strahlungsmessungen; Auswahlkriterien
DIN 5031 Beiblatt 1, Ausgabe:1982-11 Strahlungsphysik im optischen Bereich und Lichttechnik; Inhaltsverzeichnis über Größen, Formelzeichen und Einheiten sowie Stichwortverzeichnis zu DIN 5031 Teil 1 bis Teil 10
DIN 5031-2, Ausgabe:1982-03 Strahlungsphysik im optischen Bereich und Lichttechnik; Strahlungsbewertung durch Empfänger
DIN 5033-7, Ausgabe:1983-07 Farbmessung; Meßbedingungen für Körperfarben
DIN 5037 Beiblatt 1, Ausgabe:1992-08 Lichttechnische Bewertung von Scheinwerfern; Vereinfachte Nutzlichtbewertung für Film-, Fernseh- und Bühnenscheinwerfer mit rotationssymmetrischer Lichtstärkeverteilung
DIN 5037 Beiblatt 2, Ausgabe:1992-08 Lichttechnische Bewertung von Scheinwerfern; Vereinfachte Nutzlichtbewertung für Film-, Fernseh- und Bühnenscheinwerfer mit zu einer oder zwei zueinander senkrechten Ebenen symmetrischer Lichtstärkeverteilung
DIN 5039, Ausgabe:1995-09 Licht, Lampen, Leuchten - Begriffe, Einteilung
DIN 5042-1, Ausgabe:1980-10 Verbrennungslampen und Gasleuchten; Einteilung, Begriffe
DIN 5043-1, Ausgabe:1973-12 Radioaktive Leuchtpigmente und Leuchtfarben; Meßbedingungen für die Leuchtdichte und Bezeichnung der Pigmente
DIN 19010-1, Ausgabe:1979-03 Lichtelektrische Belichtungsmesser; Skalen, Kalibrieren
DIN 58141-5, Ausgabe:1993-11 Prüfung von faseroptischen Elementen; Bestimmung der Faserbruchrate von Licht- und Bildleitern
DIN 58141-10, Ausgabe:1997-02 Prüfung von faseroptischen Elementen - Teil 10: Bestimmung der Beleuchtungsstärke und des effektiven Öffnungswinkels von Kaltlichtquellen
ISO 31-6, Ausgabe:1992-09 Größen und Einheiten; Teil 6: Licht und verwandte elektromagnetische Strahlung
ISO 8599, Ausgabe:1994-12 Optik und optische Instrumente - Kontaktlinsen - Bestimmung des Spektral- und Licht-Transmissionsgrades

VII.4.b. CIE Publications
13.3-1995 : Method of measuring and specifying colour rendering of light sources New edition (including Disk D008)
15.2-1986 : Colorimetry, 2nd ed.
16-1970 : Daylight
17.4-1987 : International lighting vocabulary, 4th ed. (Joint publication IEC/CIE)
18.2-1983 : The basis of physical photometry, 2nd ed.
19.21-1981 : An analytic model for describing the influence of lighting parameters upon visual performance, 2nd ed., Vol.1.: Technical foundations
19.22-1981 : An analytic model for describing the influence of lighting parameters upon visual performance, 2nd ed., Vol.2.: Summary and application guidelines
38-1977 : Radiometric and photometric characteristics of materials and their measurement
39.2-1983 : Recommendations for surface colours for visual signalling, 2nd ed.
40-1978 : Calculations for interior lighting: Basic method
41-1978 : Light as a true visual quantity: Principles of measurement
44-1979 : Absolute methods for reflection measurements
46-1979 : A review of publications on properties and reflection values of material reflection standards
51.2-1999 : A method for assessing the quality of daylight simulators for colorimetry (with supplement 1-1999)
52-1982 : Calculations for interior lighting: Applied method
53-1982 : Methods of characterizing the performance of radiometers and photometers
55-1983 : Discomfort glare in the interior working environment
59-1984 : Polarization: Definitions and nomenclature, instrument polarization
60-1984 : Vision and the visual display unit work station
63-1984 : The spectroradiometric measurement of light sources
64-1984 : Determination of the spectral responsivity of optical radiation detectors
65-1985 : Electrically calibrated thermal detectors of optical radiation (absolute radiometers)
69-1987 : Methods of characterizing illuminance meters and luminance meters: Performance, characteristics and specifications
70-1987 : The measurement of absolute luminous intensity distributions
75-1988 : Spectral luminous efficiency functions based upon brightness matching for monochromatic point sources, 2° and 10° fields
76-1988 : Intercomparison on measurement of (total) spectral radiance factor of luminescent specimens
78-1988 : Brightness-luminance relations: Classified bibliography
82-1989 : CIE History 1913 - 1988
84-1989 : Measurement of luminous flux
85-1989 : Solar spectral irradiance
86-1990 : CIE 1988 2° spectral luminous efficiency function for photopic vision
87-1990 : Colorimetry of self-luminous displays - A bibliography
95-1992 : Contrast and visibility
96-1992 : Electric light sources - State of the art - 1991
98-1992 : Personal dosimetry of UV radiation
101-1993 : Parametric effects in colour-difference evaluation
105-1993 : Spectroradiometry of pulsed optical radiation sources
106-1993 : CIE Collection in photobiology and photochemistry (1993):
106/1: Determining ultraviolet action spectra
106/2: Photokeratitis
106/3: Photoconjunctivitis
106/4: A reference action spectrum for ultraviolet induced erythema in human skin
106/5: Photobiological effects in plant growth
106/6: Malignant melanoma and fluorescent lighting
106/7: On the quantification of environmental exposures: limitations of the concept of risk-to-benefit ratio
106/8: Terminology for photosynthetically active radiation for plants
108-1994 : Guide to recommended practice of daylight measurement (including disk)
109-1994 : A method of predicting corresponding colours under different chromatic and illuminance adaptations
114-1994 : CIE Collection in photometry and radiometry
114/1: Survey of reference materials for testing the performance of spectrophotometers and colorimeters
114/2: International intercomparison on transmittance measurement - Report of results and conclusions
114/3: Intercomparison of luminous flux measurements on HPMV lamps
114/4: Distribution temperature and ratio temperature
114/5: Terminology relating to non-selective detectors
114/6: Photometry of thermally sensitive lamps
116-1995 : Industrial colour difference evaluation
118-1995 : CIE Collection in colour and vision
118/1: Evaluation of the attribute of appearance called gloss
118/2: Models of heterochromatic brightness matching
118/3: Brightness-luminance relations
118/4: CIE guidelines for co-ordinated research on evaluation of colour appearance models for reflection print and self-luminous display image comparisons
118/5: Testing colour appearance models: Guidelines for co-ordinated research
118/6: Report on colour difference literature
118/7: CIE guidelines for co-ordinated future work on industrial colour-difference evaluation
121-1996 : The photometry and goniophotometry of luminaires
124-1997 : CIE Collection in colour and vision, 1997
124/1: Colour notations and colour order systems
124/2: On the course of the disability glare function and its attribution to components of ocular scatter
124/3: Next step in industrial colour difference evaluation - Report on a colour difference research meeting
125-1997 : Standard erythema dose
127-1997 : Measurement of LEDs
130-1998 :Practical methods for the measurement of reflectance and transmittance
134-1999 : CIE Collection in photobiology and photochemistry, 1999
134/1: Standardization of the terms UV-A1, UV-A2 and UV-B
134/2: UV protection of the eye
134/3: Recommendations on photobiological safety of lamps. A review of standards
135-1999 : CIE Collection in vision and colour and in physical measurement of light and radiation, 1999
135/1: Disability glare
135/2: Colour rendering (TC 1-33 closing remarks)
135/3: Supplement 1-1999 to CIE 51-1981: Virtual metamers for assessing the quality of simulators of CIE illuminant D50
135/4: Some recent developments in colour difference evaluation
135/5: Visual adaptation to complex luminance distribution
135/6: 45°/0° spectral reflectance factors of pressed polytetrafluoroethylene (PTFE) powder
138-2000 : CIE Collection in Photobiology and Photochemistry, 2000
138/1: Blue light photochemical retinal hazard
138/2: Action spectrum for photocarcinogenesis (non-melanoma skin cancers)
138/3: Standardized protocols for photocarcinogenesis safety testing
138/4: A proposed global UV index
139-2001 : The influence of daylight and artificial light on diurnal and seasonal variations in humans - a bibliography (also available as disk)
142-2001 : Improvement to industrial colour difference evaluation
148:2002 : Action spectroscopy of skin with tunable lasers
149:2002 : The use of tungsten filament lamps as secondary standard sources
151:2003 : Spectral weighting of solar ultraviolet radiation
CIE Draft Standard DS 010.3-2002 : Photometry - The CIE system of physical photometry
CIE Draft Standard DS 012.2:2002 : Standard method of assessing the spectral quality of daylight simulators for visual appraisal and measurement of colour
CIE Draft Standard DS 013.2:2002 : International standard global UV index
CIE Draft Standard DS 015:2002 : Lighting of work places - outdoor work places

VII.5 National Calibration Laboratories
DKD – German Accreditation Institution
The German accreditation institution DKD (Deutscher Kalibrierdienst) was founded by German trade and industry and the German state represented by the Physikalisch-Technische Bundesanstalt (PTB), the German national standards laboratory. The basic idea of the DKD is to transfer as many PTB responsibilities to industry as possible, including the calibration of measurement and testing equipment. The DKD ensures the traceability of measurement and testing equipment to national standards by the accreditation and continuous auditing of industrial calibration laboratories. Therefore, calibrations carried out by DKD accredited laboratories offer a secured traceable and well-documented link to national calibration standards. An uninterrupted traceable chain of calibration links to national standards is absolutely necessary for acceptance of measurement devices by any quality management system. The qualification of the traceability to national standards is the job of the Physikalisch-Technische Bundesanstalt (PTB), the German national standards laboratory. The PTB will define, realize, keep and transmit the physical quantities of the SI-system, such as a meter, a second, a kilogram, a candela, etc. To ensure objective results, equal standards must be used. The calibration of measurement and testing arrangements based on SI-units is a basis for correct, comparable, recognizable and therefore measurable values, which can be audited. Within the DIN ISO 9000 ff. standard the relationship between quality management and calibration are intertwined in part for continuous control of measurement and testing equipment. Without exception, DKD accredited calibration laboratories fulfill the requirements of the European standard EN 45001 (general criteria to operate a testing laboratory, May 1990). Outside of Europe this standard is not compulsory. Instead of this the ISO/IEC Guide 25 (General requirements on the competence of testing and calibration laboratories, December 1990) is recognized. In content, EN 45001 and ISO/IEC Guide 25 are identical. This is the basis for the mutual appreciation between the European cooperation for Accreditation (EA) and its extra-European partners. In 1999 ISO/IEC 17025 took the place of EN 45001 and ISO/IEC Guide 25 which eliminated any formal differences. Existing DKD calibration laboratories automatically qualify for ISO/IEC/EN 17025 conformance.

DKD homepage:

The European position of the DKD is noted by its membership in the European Cooperation for Accreditation of Laboratories (EAL) in Rotterdam, which was founded out of the Western European Calibration Cooperation (WECC) and the Western European Laboratory Accreditation Cooperation (WELAC) in 1994. Within the EAL different national accreditation institutes cooperate with the goal of international acceptance of calibration certificates of the EAL-calibration laboratories. In November 2000, 34 accreditation institutions from 28 countries, including the PTB, the accreditation institution of the DKD, signed a Mutual Recognition Arrangement (MRA) of the International Laboratory Accreditation Cooperation (ILAC). More information about this arrangement and the participating countries is available online at

Relationship between ISO/IEC 17025 and A2LA Accreditation

The American Association for Laboratory Accreditation (A2LA) provides comprehensive services in laboratory accreditation and laboratory-related training. Laboratory accreditation is based on internationally accepted criteria for competence (ISO/IEC 17025:2005).
For specifying services for external testing and calibration laboratories A2LA submits prerequisites to be met by the requesting party.  An example of these prerequisites follows.
All three paragraphs are needed to ensure that a party requesting external testing or calibration service providers has met the International Laboratory Accreditation Cooperation's (ILAC's) comprehensive technical requirements and are providing dependable data and test reports.

1. The testing or calibration laboratory shall be accredited in accordance with the requirements of ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories."

2. The testing or calibration laboratory’s scope of accreditation to ISO/IEC 17025 General requirements for the competence of testing and calibration laboratories shall encompass testing (or calibration) of (list the test methods or parameter(s) that is required for testing or calibration).

3. The accreditation of a testing or calibration laboratory shall be issued by an accreditation body (AB) operating in accordance with ISO 17011, General requirements for accreditation bodies accrediting conformity assessment bodies and is an ILAC MRA Signatory (such as A2LA).

The first paragraph stipulates that the service provider be accredited to ISO/IEC 17025, while the second paragraph requires that the tests or calibrations requested be listed on the service provider’s scope of accreditation. [If this requirement is not met, the laboratory could claim that it is ISO/IEC 17025 compliant even though it is not actually accredited for the test or calibration requested.]

The third paragraph contains two important stipulations:

1. That the laboratory used be accredited to ISO/IEC 17025.

2. That the Accreditation Body (AB) be an ILAC Mutual Recognition Arrangement (MRA) signatory. Without this paragraph, the laboratory could be accredited by an AB that has inadequate or misleading credentials. There are AB’s in the USA that claim to be in compliance with ISO 17011. One such AB sells "mail-order" accreditation services and might never visit the lab to ensure implementation of the ISO/IEC 17025 requirements or to verify its staff's technical competence. Holding ILAC MRA signatory status indicates that the AB has been periodically peer-evaluated as to the requirements of ISO 17011.  This peer evaluation process ensures that AB's meet strict international requirements; thus one can have confidence in the data and test reports produced by their accredited laboratories.

The AB for the Gigahertz-Optik calibration laboratory for optical radiation is the Deutscher Kalibrierdienst (DKD) which is an ILAC MRA signatory. DKD achieved their ILAC recognition through the European Cooperation for Accreditation (EA). A2LA is the only U.S.
accreditation body to have signed a bi-lateral agreement with the EA.Gigahertz-Optik‘s calibration laboratory is DIN EN ISO/IEC 17025 accredited for the measurement quantities Spectral Sensitivity and Spectral Irradiance under Registration Number DKD-K-10601.

For further information visit websites:

PTB – Physikalisch-Technische Bundesanstalt
The Physikalisch-Technische Bundesanstalt (PTB) is the highest technical authority for metrology in Germany. The PTB define, realize, keep and transmit the physical quantities of the SI-system, such as a meter, a second, a kilogram, a candela, etc. The PTB is the official accreditation institution for DKD calibration laboratories for optical radiation measurement quantities such as Gigahertz-Optik. The PTB is also actively working on bilateral acceptance on national standards. Because of their activities in 1995 a Statement of Intent on Traceability of Measurement Standards was signed between the Physikalisch-Technische Bundesanstalt (PTB) and the National Institute of Standards and Technology (NIST) USA. The Equivalence of the National Standards of NIST and PTB for the SI Units of Luminous Intensity and Luminous Flux was officially recognized in April 1999.
PTB homepage:

NIST – U.S. National Institute of Standards and Technology
The Optical Technology Division of NIST's Physics Laboratory has the mandate to provide a high quality national measurement infrastructure to support industry, government, and academia who are reliant upon optical technologies for their competitiveness and success. As a part of this mandate, the Division has the institutional responsibility for maintaining two SI base units: the unit for temperature, the kelvin, above 1234.96 K and the unit of luminous intensity, the candela. As part of its responsibilities the Division: Develops, improves, and maintains the national standards for radiation thermometry, spectroradiometry, photometry, colorimetry, and spectrophotometry; provides National measurement standards and support services to advance the use and application of optical technologies spanning the ultraviolet through microwave spectral regions for diverse industrial, governmental, and scientific uses; disseminates these standards by providing measurement services to customers requiring calibrations of the highest accuracy and contributes to the intellectual reservoir of technical expertise by publishing descriptions of NIST developed advances in appropriate scientific journals and books; conducts basic, long term theoretical and experimental research in photophysical and photochemical properties of materials, in radiometric and spectroscopic techniques and instrumentation, and in application of optical technologies in nanotechnology, biotechnology, optoelectronics, and in diverse industries reliant upon optical techniques. NIST Physics Laboratory Optical Technology Division Home Page, Last updated: April 2002

NRC – National Research Council Canada
The NRC’s Institute for National Measurement Standards Photometry and Radiometry Group maintains photometric, radiometric, spectrophotometric and colorimetric standards, and provides associated, high-accuracy measurement services to industry, university, and government clients involved with lighting, transportation, manufacturing, telecommunications, public health and safety, and the environment. NRC INMS Photometry & Radiometry Home Page Last Updated: 2001-07-18

NPL – National Physical Laboratory UK
The NPL is UK’s National Standards Laboratory for Physical Measurements. NPL's Optical Radiation Measurement (ORM) Group provides services which are the backbone for optical radiation measurements in the UK and internationally. Here the UK's Primary Standards and scales are maintained, and pioneering research in measurement science is carried out. ORM anticipates and responds to industrial and academic measurement requirements throughout the IR, Visible, and UV spectra, providing a comprehensive range of Measurement and Calibration Services, Instrumentation Products, Training and Consultancy. Some of the range of Measurement and Calibration Services, traceable to national standards, available in this field, includes the characterization and calibration of:

• All types of optical radiation sources
• Optical radiation detectors and associated devices
• Optical properties of materials and components
• Aspects of appearance including colour, haze and gloss

The development of NPL's Primary Standards and Measurement Scales, enables the UK to maintain the highest accuracy optical measurement references in the world as well as to enable the fostering of new ideas and techniques. Areas in which NPL is a recognized world leader include the development of the first cryogenic radiometer and the use of lasers for radiometry. NPL ORM Introduction Web Page: © Crown Copyright 2002