1、Designation: E2152 12 (Reapproved 2017)Standard Practice forComputing the Colors of Fluorescent Objects fromBispectral Photometric Data1This standard is issued under the fixed designation E2152; the number immediately following the designation indicates the year oforiginal adoption or, in the case o
2、f revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.INTRODUCTIONThe fundamental procedure for evaluating the color of a fluorescent specimen is to obtain bisp
3、ectralphotometric data for specified irradiating and viewing geometries, and from these data to computetristimulus values based on a CIE (International Commission on Illumination) standard observer anda CIE standard illuminant. Procedures for such computation are contained in this practice. Thisprac
4、tice also contains procedures for computing illuminant-specific spectral radiance factor valuesfrom illuminant-independent bispectral photometric data.1. Scope1.1 This practice provides the values and practical compu-tation procedures needed to obtain tristimulus values, desig-nated X, Y, Z and X10,
5、Y10,Z10for the CIE 1931 and 1964observers, respectively, from bispectral photometric data forthe specimen. Procedures for obtaining such bispectral photo-metric data are contained in Practice E2153.1.2 Procedures for conversion of results to color spaces thatare part of the CIE system, such as CIELA
6、B and CIELUV arecontained in Practice E308.1.3 This standard may involve hazardous materials,operations, and equipment. This standard does not purport toaddress all of the safety concerns, if any, associated with itsuse. It is the responsibility of the user of this standard toestablish appropriate s
7、afety, health, and environmental prac-tices and determine the applicability of regulatory limitationsprior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment o
8、f International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2E284 Terminology of AppearanceE308 Practice for Computing the Colors of Objects by Usingthe CIE SystemE2153 Practice for
9、 Obtaining Bispectral Photometric Datafor Evaluation of Fluorescent Color2.2 CIE Standards:CIE 15 Colorimetry32.3 ISO Standards:ISO 11476 Paper and BoardDetermination of CIE-Whiteness, C/2 Degrees43. Terminology3.1 DefinitionsThe definitions contained in TerminologyE284 are applicable to this practi
10、ce.3.2 Definitions of Terms Specific to This Standard:3.2.1 bispectrometer, nan optical instrument equippedwith a source of irradiation, two monochromators, and adetection system, such that a specimen can be measured atindependently-controlled irradiation and viewing wavelengths.The bispectrometer i
11、s designed to allow for calibration to1This practice is under the jurisdiction of ASTM Committee E12 on Color andAppearance and is the direct responsibility of Subcommittee E12.05 on Fluores-cence.Current edition approved Nov. 1, 2017. Published November 2017. Originallyapproved in 2001. Last previo
12、us edition approved in 2012 as E2152 12. DOI:10.1520/E2152-12R17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM webs
13、ite.3Available from CIE (International Commission on Illumination) at www-.cie.co.at or .4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken,
14、 PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organizatio
15、n Technical Barriers to Trade (TBT) Committee.1provide quantitative determination of the bispectral radiation-transfer properties of the specimen (1).5NOTE 1Typically, a reference detection system monitors the radiationincident on the specimen. This reference detection system serves tocompensate for
16、 both temporal and spectral variations in the flux incidentupon the specimen, by normalization of readings from the instrumentsemission detection system.3.2.2 diagonal elements, nelements of a bispectral matrixfor which irradiation and viewing wavelengths are equal.3.2.3 fluorescence, nthis standard
17、 uses the term “fluores-cence” as a general term, including both true fluorescence(with a luminescent decay time of less than 10-8s) andphosphorescence with a delay time short enough to be indis-tinguishable from fluorescence for the purpose of colorimetry.3.2.4 off-diagonal element, nany element of
18、 a bispectralmatrix for which irradiation and viewing wavelengths are notequal.4. Summary of Practice4.1 ProceduresProcedures are given for computing frombispectral photometric measurements the CIE tristimulus val-ues X, Y, Z for the CIE 1931 standard observer and the CIE1964 supplementary standard
19、observer. While recognizing theCIE recommendation of numerical integration at 1 nm intervals(in CIE 15) as the basic definition, this practice is limited inscope to measurements and calculations using spectral inter-vals greater than or equal to 5 nm.4.2 CalculationsCIE tristimulus values X, Y, Z or
20、 X10,Y10,Z10are calculated by numerical summation of the prod-ucts of weighting factors for selected illuminants and observerswith the bispectral Donaldson radiance factor of the specimen.The tristimulus values so calculated may be converted tocoordinates in a more nearly uniform color space such as
21、CIELAB or CIELUV.5. Significance and Use5.1 The bispectral or two-monochromator method is thedefinitive method for the determination of the generalradiation-transfer properties of fluorescent specimens (2).Inthis method, the measuring instrument is equipped with twoseparate monochromators. The first
22、, the irradiationmonochromator, irradiates the specimen with monochromaticlight. The second, the viewing monochromator, analyzes theradiation leaving the specimen. A two-dimensional array ofbispectral photometric values is obtained by setting the irra-diation monochromator at a series of fixed wavel
23、engths () inthe ultraviolet and visible range, and for each , using theviewing monochromator to record readings for each wave-length () in the visible range. The resulting array, onceproperly corrected, is known as the Donaldson matrix, and thevalue of each element (,) of this array is here describe
24、d as theDonaldson radiance factor (D(,). The Donaldson radiancefactor is an instrument- and illuminant-independent photomet-ric property of the specimen, and can be used to calculate itscolor for any desired illuminant and observer. The advantage ofthis method is that it provides a comprehensive cha
25、racteriza-tion of the specimens radiation-transfer properties, without theinaccuracies associated with source simulation and variousmethods of approximation.6. Procedure6.1 Selecting Standard ObserverSelect standard observeraccording to the guidelines of Practice E308.6.2 Selecting IlluminantsSelect
26、 illuminants that are simi-lar to the light under which the objects will be viewed or forwhich their colors will be specified or evaluated. In general,follow the recommendations of Practice E308. For fluorescentsamples, however, special attention must be given to therelative UV content of the select
27、ed illuminants and the lightunder which the objects will be viewed.6.2.1 When object will be viewed indoors, by daylightfiltered through a glass window, use values for the extendedversion of Illuminant C defined in ISO 11476.6.2.2 When object will be viewed outdoors, by unfiltereddaylight, use value
28、s for CIE Illuminant D65, or other daylightilluminants, as defined by the formulas developed by Judd, andpresented in CIE 15.6.2.3 When object will be viewed under well-defined spe-cial conditions of irradiation which are not similar to anystandard illuminant, a provisional illuminant may be defined
29、.Such a provisional illuminant must represent the relativespectral irradiance upon the object surface under these specialconditions.7. Calculation7.1 Calculation of Colorimetric QuantitiesUse themethod of calculating tristimulus values at 5 nm intervals overthe viewing wavelength range 380 to 780 nm
30、, and irradiationwavelength range 300 to 780 nm.7.2 Calculation of Tristimulus ValuesThe calculation pro-cedures described below involve numerical summation of theproducts of the Donaldson radiance factor of the specimen anda bispectral factor derived from the tabulated standard illumi-nant and obse
31、rver functions. After normalization, the sums arethe CIE tristimulus values X, Y, Z (3, 2, 1).7.2.1 Application of Illuminant WeightsSelect the desiredCIE standard illuminant from Tables given in Practice E308.Multiply each element D(,) of the specimens Donaldsonmatrix by the tabulated value of the
32、relative spectral power ofthe illuminant at the elements irradiation wavelength ().7.2.2 Calculation of Stimulus FunctionObtain the sumover of these products at 5 nm intervals over the wavelengthrange 300 to 780 nm. The sum obtained at each viewingwavelength is the value of the specimens stimulus fu
33、nction(relative spectral radiance) F(), under the specified conditionsof irradiation. From these values, either tristimulus values orspectral radiance factor values may be derived.F! 5(5300780!D,! (1)7.2.3 Derivation of Tristimulus ValuesUse the color-matching functions selected in 6.1. Multiply the
34、 specimens5The boldface numbers in parentheses refer to a list of references at the end ofthis standard.E2152 12 (2017)2stimulus function at each viewing wavelength () by thecorresponding tabulated values of the observer color-matchingfunctions. Obtain the sum of these spectral products at 5 nminter
35、vals over the wavelength range 380 to 780 nm:X 5 k(5380780xH!F! (2)Y 5 k(5380780yH!F!Z 5 k(5380780zH!F!where:k = the normalization constant:k 5100(5380780!yH!(3)7.3 Derivation of Other Colorimetric QuantitiesOthercolorimetric values, such as chromaticity coordinates, CIELABand CIELUV values, may be
36、calculated from tristimulus valuesas described in Practice E308.NOTE 2The validity of CIELAB and CIELUV values for describingthe color of fluorescent materials is subject to question, for two reasons.First, because the appearance of a fluorescent material may be influencedby irradiation at wavelengt
37、hs outside the visible range, the appropriatedefinition of the “white point” (incorporated in the CIELAB and CIELUVcalculations) is not clear. Second, the perceptual uniformity of these colorspaces has not been evaluated in regions where L* exceeds 100, as it mayfor fluorescent materials. It is the
38、responsibility of the user to determinethe appropriateness of such metrics for any particular specimen andapplication.7.4 Derivation of Spectral Radiance FactorsCalculate thespecimens stimulus function (relative spectral radiance) F()for the selected illuminant as described in section 7.2.2. DivideF
39、 at each viewing wavelength () by the correspondingtabulated value of the relative spectral power Iof the selectedilluminant. Note that for a fluorescent specimen, the spectralradiance factor (I() is illuminant-specific (3).I! 5FI!I!5(5300780I!I!D,! (4)7.5 Separation of Fluorescence and ReflectionCo
40、mponentsFluorescence and reflection components of tris-timulus and spectral radiance factor values can be calculated bysubstituting the fluorescent or reflection components of Don-aldson radiance factor (DFor DR) for Donaldson radiancefactor (D) in the calculations described in sections 7.2 and 7.3.
41、This separation of components is valid for D, , and tristimulusvalues; it may not be valid for other colorimetric values.7.5.1 Estimation of ComponentsTo a first approximation,the contribution of fluorescence and reflectance to the appear-ance of the specimen can be separated by treating diagonalval
42、ues of the Donaldson matrix as representing reflectanceonly, and off-diagonal values as representing fluorescence.7.5.2 Calculation of ComponentsWhile more rigorousand accurate methods for the separation of reflection andfluorescence components may be employed, description ofsuch calculations lies o
43、utside the scope of this standard.7.6 Abridged Calculation Procedures:7.6.1 Wavelength Intervals of Greater than 5 nmWhendata for D(,) are not available at 5 nm intervals, estimatedvalues at 5 nm intervals should be derived by appropriateinterpolation, as described in Annex A1.7.6.2 Viewing Waveleng
44、th Range Less Than 380-780 nmWhen data for D(,) are not available for the full viewingwavelength range, add the illuminant or observer weights, orboth, at the wavelengths for which data are not available to theweights at the shortest and longest wavelength for whichspectral data are available. Note
45、that such use of spectrally-truncated data is not recommended when significant fluores-cent emission occurs in the region of truncation.7.6.3 Irradiation Wavelength Range Less Than 300-780nmWhen the bispectral region of fluorescence is known fora particular specimen, it is acceptable to limit the co
46、llection offluorescence data (off-diagonal values) to this region. Com-plete the standard Donaldson matrix by setting off-diagonalvalues outside this region to zero.8. Report8.1 The report of the measurement of colorimetric forfluorescent samples data shall include the following:8.2 Specimen Descrip
47、tionIncluding the following:8.2.1 Type and identification,8.2.2 Date of preparation or manufacture, if required,8.2.3 Method of cleaning and date, if cleaned,8.2.4 Orientation of the specimen during measurement, and8.2.5 Any changes in the specimen during measurement.8.3 Source of DateGive instrumen
48、t identification, irradi-ating and viewing geometry, spectral bandpass, and date ofmeasurement.8.4 ObserverIndicate whether the reported data werecomputed for the CIE 1931 standard observer (2) or the 1964supplementary standard observer (10).8.5 IlluminantsIndicate which illuminants were used.8.6 Me
49、thod of CalculationIndicate whether the procedureusinga5nmwavelength interval, or a specified abridgedprocedure was used, and what wavelength range of spectraldata was available.8.7 Colorimetric DataReport according to the guidelinesof Practice E308.8.8 Spectral Radiance Factor (Optional)When reportingspectral radiance factor values for fluorescent samples, indicatefor which illuminant the reported spectral radiance factor isdefined.9. Keywords9.1
