1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58ICS 17.180.01Photometry The CIE system of physical photometry BRITISH STANDARDBS ISO 23539:2005BS I
2、SO 23539:2005This British Standard was published under the authority of the Standards Policy and Strategy Committee on 23 January 2006 BSI 23 January 2006ISBN 0 580 46881 XCross-referencesThe British Standards which implement international publications referred to in this document may be found in th
3、e BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online.This publication does not purport to include all the necessary provisions of a contract. Users are responsible f
4、or its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations.Summary of pagesThis document comprises a front cover, an inside front cover, the ISO title page, pages ii and iii, a blank page, pages 1 to 18, an inside back cover and a back co
5、ver.The BSI copyright notice displayed in this document indicates when the document was last issued.Amendments issued since publicationAmd. No. Date CommentsA list of organizations represented on this subcommittee can be obtained on request to its secretary. present to the responsible international/
6、European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK.National forewordThis British Standard reproduces verbatim ISO 23539:2005 and implements it as the UK
7、 national standard.The UK participation in its preparation was entrusted by Technical Committee CPL/34, Lamps and related equipment, to Subcommittee CPL/34/5, Photometry and light classifications, which has the responsibility to: aid enquirers to understand the text;Reference numberISO 23539:2005(E)
8、CIE S 010/E:2004INTERNATIONAL STANDARD ISO23539CIE S 010/EFirst edition2005-08-01Photometry The CIE system of physical photometry Photomtrie Le systme CIE de photomtrie physique BS ISO 23539:2005ii iiiForeword ISO (the International Organization for Standardization) is a worldwide federation of nati
9、onal standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. Internat
10、ional organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. ISO 23539 was prepared as Standard CIE S 010/E by the Interna
11、tional Commission on Illumination, which has been recognized by the ISO Council as an international standardizing body. It was adopted by ISO under a special procedure which requires approval by at least 75 % of the member bodes casting a vote, and is published as a joint ISO/CIE edition. The Intern
12、ational Commission on Illumination (abbreviated as CIE from its French title) is an organization devoted to international cooperation and exchange of information among its member countries on all matters relating to the science and art of lighting. ISO 23539 was prepared by CIE Technical Committee 2
13、-35 CIE Standard for V() and V(). BS ISO 23539:2005blank1PHOTOMETRY - THE CIE SYSTEM OF PHYSICAL PHOTOMETRY INTRODUCTIONThe visual brightness of a light source depends not only on the amount of radiation it emits but also on its spectral composition and on the visual response function of the observe
14、r viewing it. Because human visual response varies at different light levels and from person to person, precise photometry requires the definition of representative standard observers. The CIE system of physical photometry specifies procedures for the quantitative evaluation of optical radiation in
15、terms of the spectral luminous efficiency functions of two such standardobservers. One, V(O), represents photopic vision and the other, V (O), scotopic vision. Used in conjunction with the SI photometric base unit, the candela, these functions constitute asystem that enables the values of photometri
16、c quantities for all types of luminous source to be precisely determined, regardless of the spectral composition of the radiation emitted. 1. SCOPE This international Standard specifies the characteristics of the system of physical photometry established by the CIE and accepted as the basis for the
17、measurement of light. It defines thephotometric quantities, units and standards that make up the CIE system of physical photometry and that have been officially accepted by the Comit International des Poids etMesures (CIPM). They comprise: the definition of photometric quantities and units, the defi
18、nition of CIE standard spectral luminous efficiency functions for photopic and scotopic vision, the definition of a CIE standard photometric observer that conforms to these functions, the definition of maximum luminous efficacies for photopic and scotopic vision. An informative annex provides a voca
19、bulary of related terms. 2. PHOTOMETRIC QUANTITIES Photometric quantities are defined in the International Lighting Vocabulary (ILV) (CIE, 1987a). 2.1 Luminous flux The fundamental physical quantity used in optical radiometry is the radiant flux or radiant power, )e, measured in watts, which is emit
20、ted by a source of radiation, transmitted by a medium of propagation, or received at a surface. The corresponding photometric quantity is: luminous flux ()v) (see ILV 845-01-25)quantity derived from radiant flux )eby evaluating the radiation according to its action uponthe CIE standard photometric o
21、bserverThe procedure for deriving )v from )e is defined in 4.3, below. 2.2 Other quantities The following are the photometric quantities that correspond to the most important radiometric quantities defined in the International Lighting Vocabulary. luminous energy (also known as quantity of light) (Q
22、v) (see ILV 845-01-28)time integral of the luminous flux )vover a given duration t ttQ dvv)luminous intensity (of a source in a given direction) (Iv) (see ILV 845-01-31) quotient of the luminous flux d)vleaving the source and propagated in the element of solid angle d: containing the given direction
23、, by the element of solid angle BS ISO 23539:20052 ddvv) I luminance (in a given direction, at a given point of a real or imaginary surface) (Lv) (see ILV 845-01-35)quantity defined by the formula ALdcosddvv T)where d)vis the luminous flux transmitted by an elementary beam passing through the given
24、point and propagating in the solid angle d: containing the given direction; dA is the area of a section of that beam containing the given point; T is the angle between the normal to thatsection and the direction of the beamilluminance (at a point of a surface) (Ev) (see ILV 845-01-38)quotient of the
25、 luminous flux d)vincident on an element of the surface containing the point, by the area dA of that element AEddvv) luminous exitance (at a point of a surface) (Mv) (see ILV 845-01-48)quotient of the luminous flux d)vleaving an element of the surface containing the point, by the area dA of that ele
26、ment AMddvv) 3. PHOTOMETRIC UNITS 3.1 Candela The SI photometric base unit is the candela (cd), the unit of luminous intensity. It was defined by the Confrence Gnrale des Poids et Mesures (CGPM) in 1979 (CGPM, 1979), as follows:The candela is the luminous intensity, in a given direction, of a source
27、 that emits monochromatic radiation of frequency 540 x 1012hertz and that has a radiant intensity in that direction of (1/683) watt per steradian. This definition of the candela applies equally to photopic, scotopic, and mesopicvision.3.2 Other units The SI units of other photometric quantities can
28、be derived from the candela and the SI units of length (m), solid angle (sr) and time (s). Thus: Quantity Symbol SI UnitLuminous flux )vlm = cdsrLuminous energy QvcdsrsLuminance Lvcdm-2Illuminance Evlx = cdsrm-2Luminous exitance Mvcdsrm-2BS ISO 23539:200534. PHOTOMETRIC STANDARDS 4.1 CIE Standard sp
29、ectral luminous efficiency functions for photopic and scotopic visionThis Standard defines two spectral luminous efficiency functions for photometric measurements:- The V(O) function, which applies to photopic vision and should be used formeasurements at luminance levels of at least several candelas
30、 per square metre. It is defined by the numerical values given in Table 1 of this Standard, the wavelength being measured in standard air (Birch, 1994). For numerical computations, the peak value of the V(O) function should be evaluated at 555 nm exactly. Linear interpolation should be used exclusiv
31、ely to evaluate V(O) at wavelengths intermediate to those given in Table 1; - The V (O) function, which applies to scotopic vision and should be used formeasurements at luminance levels less than some hundredths of a candela per square metre. This function is defined by the numerical values in Table
32、 2 of this Standard, the wavelength O again being measured in standard air. For numerical computations, the peak value of the V (O) function should be evaluated at 507 nm exactly. Linear interpolation should be used exclusively to evaluate V (O) at wavelengths intermediate to those given in Table 2.
33、 An ideal observer having a relative spectral responsivity curve that conforms to theV(O) function for photopic vision or the V (O) function for scotopic vision, and that complies with the summation law implied in the definition of luminous flux, is known as a CIE standard photometric observer.The C
34、IE has not, so far, defined standard spectral luminous efficiency functions forthe mesopic region, intermediate between the ranges of photopic and scotopic vision. 4.2 Maximum luminous efficacies for photopic and scotopic visionThe V(O) and V (O) functions defined in this Standard supplement the 197
35、9 candela definition in a manner that, taken together, these definitions constitute a rational system of physical photometry which correlates the radiant power of broadband radiation acting upon the human visual system with the physiological characteristics of the latter, is consistent with visual e
36、xperience for photopic and scotopic vision, establishes precisely defined numerical relationships between radiometric and photometric quantities.Based on the following definitions and considerations, these numerical relationships are defined by equations (1) to (4), below. luminous efficacy (for mon
37、ochromatic radiation of wavelength O) K(O) and K (O)Quotient of the luminous flux )vby the corresponding radiant flux )e (for photopic vision) (1)1evmWlm )OO VKK 1evmWlm )OO VKK (for scotopic vision) (2)where the maximum values of K(O) and K (O) are denoted by Kmand Kmso that Km=K(555 nm) and Km= K
38、(507 nm). The frequency 540 x 1012Hz corresponds to a wavelength of 555,016 nm in standard air and it follows from the candela definition that K(555,016 nm) =K (555,016 nm) = 683 lmW-1. Therefore, according to equations 1 and 2, Km= 683 lmW-1 / V(555,016 nm) = 683,002 lmW-1(3) Km= 683 lmW-1 / V (555
39、,016 nm) = 1700,05 lmW-1(4) For all practical photometric applications, Kmcan be taken as equal to 683 lmW-1and Kmas equal to 1700 lmW-1.BS ISO 23539:20054 4.3 Fundamental equations relating photometric and radiometric quantities The method for implementing the definition of luminous flux given in 2
40、.1 is based on equations (1) to (4), above. If the luminous flux in question pertains to photopic vision, it is related to thecorresponding spectral concentration of radiant flux by the equation OO)Od0e,mvVK f(5)and the corresponding relation for scotopic vision is OO)Od0e,mvVK f(6)In these equation
41、s Kmand Kmare defined by equations (3) and (4) above and V(O) and V (O)are defined by Tables 1 and 2 of this Standard.Equations (5) and (6) are fundamental to the CIE system of physical photometry. 4.4 Measurement procedures In practice, the spectral weighting required by equations (5) and (6) can b
42、e realized by means of absolutely calibrated, V(O) or V (O) corrected detectors that conform to the definition of the CIE standard photometric observer. In such cases, the integrations specified are performed by the detector itself. The evaluation of photometers designed to measure light is dealt wi
43、th in the Publication CIE 69 1987, Methods of Characterizing Illuminance Meters and LuminanceMeters (CIE, 1987b). Alternatively, it is possible to make spectroradiometric measurements (CIE, 1984) and obtain the required integrals by numerical computation from the spectroradiometric data. In this cas
44、e, the integrations usually take the form of numerical summations over the visible spectrum. The tabulated values of V(O) and V (O) at 1 nm intervals are normally sufficient for this purpose, but if intermediate values are required, these should be obtained from the tabulated values by linear interp
45、olation.In this Standard, values are given for the photopic standard observer V(O) over thespectral range from 360 nm to 830 nm (Table 1) and for the scotopic standard observer V (O)over the spectral range from 380 nm to 780 nm (Table 2). The CIE does not define values for the standard observers out
46、side these spectral ranges, because, for all practical photometric purposes, the visual contribution at longer or shorter wavelength is negligible. Definitive values of the photometric quantities will be obtained if the summation is carried out at 1 nm intervals and the limits set to 360 nm and 830
47、nm in equation (5) and to 380 nm and 780 nm in equation (6). The above equations and measurement procedures can be applied to any of the photometric quantities defined in 2.2. For example, luminance (for photopic vision) may be evaluated as OOOd0e,mvVLKL fwhere Le,Ois the corresponding spectral conc
48、entration of radiance. BS ISO 23539:20055TABLESTable 1. Definitive values of the spectral luminous efficiency function for photopic vision V(O)WavelengthnmSpectral luminous efficiency360 0,000 003 917 000 361 0,000 004 393 581 362 0,000 004 929 604 363 0,000 005 532 136 364 0,000 006 208 245 365 0,000 006 965 000 366 0,000 007 813 219 367 0,000 008 767 336 368 0,000 009 839 844 369 0,000 011 043 23 370 0,000 012 390 00 371 0,000 013 886 41 372 0,000 015 557 28 373 0,000 017 442 96 374 0,000 019 583 75 375 0,000 022 020 00 376 0,000 024 839 65 377 0,000 0
