1、Designation: E2153 01 (Reapproved 2011)Standard Practice forObtaining Bispectral Photometric Data for Evaluation ofFluorescent Color1This standard is issued under the fixed designation E2153; the number immediately following the designation indicates the year oforiginal adoption or, in the case of r
2、evision, 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 bispect
3、ralphotometric 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. The considerations involved and the procedures used to obtain precisebispec
4、tral photometric data are contained in this practice. Values and procedures for computing CIEtristimulus values from bispectral photometric data are contained in Practice E2152. Generalconsiderations regarding the selection of appropriate irradiating and viewing geometries are containedin Guide E179
5、; further specific considerations applicable to fluorescent specimens are contained in thispractice.1. Scope1.1 This practice addresses the instrumental measurementrequirements, calibration procedures, and material standardsneeded for obtaining precise bispectral photometric data forcomputing the co
6、lors of fluorescent specimens.1.2 This practice lists the parameters that must be specifiedwhen bispectral photometric measurements are required inspecific methods, practices, or specifications.1.3 This practice applies specifically to bispectrometers,which produce photometrically quantitative bispe
7、ctral data asoutput, useful for the characterization of appearance, as op-posed to spectrofluorimeters, which produce instrument-dependent bispectral photometric data as output, useful for thepurpose of chemical analysis.1.4 The scope of this practice is limited to the discussion ofobject-color meas
8、urement under reflection geometries; it doesnot include provisions for the analogous characterization ofspecimens under transmission geometries.1.5 This standard may involve hazardous materials, opera-tions, and equipment. This standard does not purport toaddress all of the safety concerns, if any,
9、associated with itsuse. It is the responsibility of the user of this standard toestablish appropriate safety and health practices and deter-mine the applicability of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E179 Guide for Selection of Geometric Conditions forMea
10、surement of Reflection and Transmission Properties ofMaterialsE284 Terminology of AppearanceE925 Practice for Monitoring the Calibration of Ultraviolet-Visible Spectrophotometers whose Spectral Bandwidthdoes not Exceed 2 nmE958 Practice for Measuring Practical Spectral Bandwidthof Ultraviolet-Visibl
11、e SpectrophotometersE1164 Practice for Obtaining Spectrometric Data forObject-Color EvaluationE1341 Practice for Obtaining Spectroradiometric Data fromRadiant Sources for ColorimetryE2152 Practice for Computing the Colors of FluorescentObjects from Bispectral Photometric Data2.2 NPL Publications:1Th
12、is 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, 2011. Published November 2011. Originallyapproved in 2001. Last previous edition approved in 2006 as E2153 - 01
13、 (2006).DOI: 10.1520/E2153-01R11.2For 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 website.1Copyright ASTM Internationa
14、l, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.NPL Report MOM 12 Problems of spectrofluorimetric stan-dards for reflection and colorimetric use32.3 CIE Publications:CIE No. 38 Radiometric and Photometric Characteristics ofMaterials and Their Measurement4CIE No
15、.15.2 Colorimetry, 2nd Edition4CIE Report of TC-2.25: Calibration Methods and Photolu-minescent Standards for Total Radiance Factor Measure-ment42.4 NIST Publications:NBS No. 260-66 Didymium Glass Filters for Calibratingthe Wavelength Scale of Spectrophotometers53. Terminology3.1 DefinitionsThe defi
16、nitions contained in TerminologyE284 are applicable to this practice.3.2 Definitions of Terms Specific to This Standard:3.2.1 bispectral fluorescence radiance factor, bFl(), ntheratio of the spectral radiance at wavelength l due to fluores-cence from a point on the specimen when irradiated atwavelen
17、gth to the total radiance of the perfectly reflectingdiffuser similarly irradiated and viewed (see NPL ReportMOM 12).3.2.2 bispectral radiance factor, bl() , nthe ratio of thespectral radiance (radiance per unit waveband) at wavelength lfrom a point on a specimen when irradiated at wavelength tothe
18、total (integrated spectral) radiance of the perfectly reflect-ing diffuser similarly irradiated and viewed.bl! Ll!/L!d(1)3.2.3 bispectral reflection radiance factor, bRl() , ntheratio of the spectral radiance at wavelength l due to reflectionfrom a point on the specimen when irradiated at wavelength
19、 to the total radiance of the perfectly reflecting diffuser similarlyirradiated and viewed.3.2.4 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 vie
20、wing wavelengths.The bispectrometer is designed to allow for calibration toprovide quantitative determination of the bispectral radiation-transfer properties of the specimen. (6)NOTE 1Typically, a reference detection system monitors the radiationincident on the specimen. This reference detection sys
21、tem serves tocompensate for both temporal and spectral variations in the flux incidentupon the specimen, by normalization of readings from the instrumentsemission detection system.3.2.5 diagonal elements, nelements of a bispectral matrixfor which irradiation and viewing wavelengths are equal.3.2.6 d
22、iagonal fluorescence, nthe contribution of fluores-cence to diagonal values of a bispectral radiance factor matrix,due to the finite range of actual irradiation and viewingwavelengths when nominal irradiation and viewing wave-lengths are equal ( = l).3.2.7 discrete bispectral radiance factor, B(,l),
23、 nthematrix defined for specified irradiation and viewing bandpassfunctions, and viewing-wavelength sampling interval (Dl) asfollows:B,l! bl! Dl (2)where:bl()= the average bispectral radiance factor of the speci-men, as weighted by the specified irradiation andviewing bandpass functions.3.2.8 Donald
24、son radiance factor, D(,l), na special caseof the discrete bispectral radiance factor, for which the speci-fied irradiation and viewing bandpass functions are perfectlyrectangular, with bandwidth equal to irradiation and viewing-wavelength sampling interval.NOTE 2The Donaldson radiance factor is app
25、roximately equal to theratio of the specimen radiance within the rectangular waveband of widthDl centered at l to the radiance of the perfect reflecting diffuser wheneach is irradiated over the rectangular waveband of width Dl centered at.3.2.9 fluorescence, nthis standard uses the term “fluores-cen
26、ce” 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.3.2.10 near-diagonal element, noff-diagonal elements ofan uncorrected
27、bispectral matrix whose values include asignificant reflection component, due to reflection overspill.For instruments with irradiation and viewing bandpass func-tions which approximate the recommended trapezoidal ortriangular shape, this should be limited to within two to threebands of the diagonal.
28、3.2.11 off-diagonal element, nany element of a bispectralmatrix for which irradiation and viewing wavelengths are notequal.3.2.12 reflection overspill, nthe contribution of reflectionto off-diagonal values of the discrete bispectral radiance factormatrix, due to the partial overlap of irradiation an
29、d viewingwavebands when nominal irradiation and viewing wavelengthsare not equal (fil).3.2.13 spectral effciency factor, b(), nthe ratio of thetotal (integrated spectral) radiance from a point on a specimenwhen irradiated at wavelength to the total radiance of theperfectly reflecting diffuser identi
30、cally irradiated and viewed.b! L!/L!d(3)4. Summary of Practice4.1 Procedures are given for selecting the types and oper-ating parameters of bispectrometers used to provide data forthe calculation of CIE tristimulus values and other colorimetricvalues to quantify the colors of objects. The important
31、steps inthe calibration of such instruments, and the material standardsrequired for these steps, are described. Guidelines are given forthe selection of specimens to obtain the highest measurementprecision. Parameters are identified which must be specified3Available from National Physical Laboratory
32、, Queens Road, Teddington,Middlesex, United Kingdom TW11 0LW, http:/www.npl.co.uk/.4Available from U.S. National Committee of the CIE (International Commissionon Illumination), C/o Thomas M. Lemons, TLA-Lighting Consultants, Inc., 7 PondSt., Salem, MA 01970, http:/www.cie-usnc.org.5Available from Na
33、tional Institute of Standards and Technology (NIST), 100Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http:/www.nist.gov.E2153 01 (2011)2when bispectral photometric measurements are required inspecific test methods or other documents.4.2 In this practice, the measuring instrument, a bispectrom
34、-eter, is equipped with two separate monochromators. The first,the irradiation monochromator, irradiates the specimen withmonochromatic light. The second, the viewing monochroma-tor, analyzes the radiation leaving the specimen. A two-dimensional array of bispectral photometric values is obtainedby s
35、etting the irradiation monochromator at a series of fixedwavelengths () in the excitation band of the specimen, and foreach , using the viewing monochromator to record readingsfor each wavelength (l) in the specimens emission range. Theresulting array, once properly corrected, is known as theDonalds
36、on matrix (2), and the value of each element (,l) ofthis array is the Donaldson radiance factor (D(,l).4.3 While recognizing the CIE recommendation (in CIEPublication 15.2) of numerical integration at 1 nm intervals asthe basic definition, this practice is limited in scope tomeasurements and calcula
37、tions using spectral intervals greaterthan or equal to 5 nm.5. Significance and Use5.1 The bispectral or two-monochromator method is thedefinitive method for the determination of the general(illuminant-independent) radiation-transfer properties of fluo-rescent specimens (2). The Donaldson radiance f
38、actor is aninstrument- and illuminant-independent photometric propertyof the specimen, and can be used to calculate its color for anydesired illuminant and observer. The advantage of this methodis that it provides a comprehensive characterization of thespecimens radiation-transfer properties, withou
39、t the inaccura-cies associated with source simulation and various methods ofapproximation.5.2 This practice provides a procedure for selecting theoperating parameters of bispectrometers used for providingdata of the desired precision. It also provides for instrumentcalibration by means of material s
40、tandards, and for selection ofsuitable specimens for obtaining precision in the measure-ments.6. Requirements for Bispectral Photometry6.1 When describing the measurement of specimens by thebispectral method, the following must be specified:6.1.1 The photometric quantity determined, such as Donald-s
41、on radiance factor or spectral efficiency factor.6.1.2 The geometry of irradiation and viewing, includingthe following:6.1.2.1 For bi-directional geometry, whether annular, cir-cumferential, or uniplanar measurement conditions are to beused, and the number and angular distribution of any multiplebea
42、ms.6.1.2.2 For hemispherical geometry, whether total or diffusemeasurement conditions (specular component of reflectanceincluded or excluded) are to be used.6.1.3 The spectral parameters for both irradiation and view-ing, including wavelength range, wavelength measurementinterval, and spectral bandp
43、ass.6.1.4 Identification of the material standards used for instru-ment calibration.6.1.5 Special requirements determined by the nature of thespecimen, such as measurement orientation for anisotropicspecimens.7. Apparatus7.1 BispectrometerThe basic instrumental requirement isa bispectrometer designe
44、d for measurement of Donaldsonradiance factor using one or more of the standard irradiationand viewing geometries described in Section 8.7.2 IrradiatorThe irradiator, which consists of the radia-tion source, a dispersive element and related optical compo-nents, shall irradiate the specimen with mono
45、chromatic radia-tion of known wavelength bandpass and measurement interval.7.2.1 The radiation source must be stable with time andhave adequate energy output over the wavelength range usedfor specimen irradiation.7.2.2 The dispersive element, which provides energy innarrow wavelength bands across th
46、e UV and visible spectralrange, may be a prism, a grating, or one of various forms ofinterference filters or wedges. The element should conform tothe following requirements:7.2.2.1 When highest measurement accuracy is required, thewavelength range should extend from 300-830 nm; otherwisethe range fr
47、om 300 to 780 nm should suffice. For specimensconfirmed to be non-fluorescent or those exhibiting onlyvisible-activated fluorescence (negligible excitation below 380nm), the wavelength range from 380 to 780 can be used. Eachuser must decide whether the loss of accuracy in the measure-ments is neglig
48、ibly small for the purpose for which data areobtained.7.2.2.2 The wavelength interval should be 5 or 10 nm. Useof wider wavelength intervals, such as 20 nm, may result inreduced accuracy. Each user must decide whether the loss ofaccuracy in the measurements is negligibly small for thepurpose for whi
49、ch data are obtained.7.2.2.3 The irradiation wavelength interval should equal theviewing wavelength interval.7.2.2.4 The spectral bandpass (full-width at half maximumpower in the band of wavelengths transmitted by the dispersiveelement) should, for best results, be equal to the wavelengthinterval. The spectral bandpass function should be symmetri-cal, and approximately triangular or trapezoidal.7.2.3 The irradiator should uniformly irradiate the sample.7.3 ReceiverThe receiver consists of the detector, a dis-per
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