1、Designation: E 2153 01 (Reapproved 2006)Standard Practice forObtaining Bispectral Photometric Data for Evaluation ofFluorescent Color1This standard is issued under the fixed designation E 2153; the number immediately following the designation indicates the year oforiginal adoption or, in the case of
2、 revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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. The considerations involved and the procedures used to obtain precisebis
4、pectral photometric data are contained in this practice. Values and procedures for computing CIEtristimulus values from bispectral photometric data are contained in Practice E 2152. Generalconsiderations regarding the selection of appropriate irradiating and viewing geometries are containedin Guide
5、E 179; further specific considerations applicable to fluorescent specimens are contained inthis practice.1. Scope1.1 This practice addresses the instrumental measurementrequirements, calibration procedures, and material standardsneeded for obtaining precise bispectral photometric data forcomputing t
6、he colors 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
7、bispectral 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
8、 measurement 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
9、any, 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:2E 179 Guide for Selection of Geometric Conditions
10、forMeasurement of Reflection and Transmission Properties ofMaterialsE 284 Terminology of AppearanceE 925 Practice for Monitoring the Calibration ofUltraviolet-Visible Spectrophotometers whose SpectralSlit Width does not Exceed 2 nmE 958 Practice for Measuring Practical Spectral Bandwidthof Ultraviol
11、et-Visible SpectrophotometersE 1164 Practice for Obtaining Spectrometric Data forObject-Color EvaluationE 1341 Practice for Obtaining Spectroradiometric Datafrom Radiant Sources for ColorimetryE 2152 Practice for Computing the Colors of FluorescentObjects from Bispectral Photometric Data2.2 NPL Publ
12、ications:1This 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 Dec. 1, 2006. Published December 2006. Originallyapproved in 2001. Last previous edition approved in 2001 a
13、s E 2153 - 01.2For 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 International, 100 Barr Harbor
14、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.15.2 Colorimetry,
15、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 definitions contained i
16、n TerminologyE 284 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 atwavelength to the total r
17、adiance 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 total (integrated
18、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 to the total radi
19、ance 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 viewing wavelengths.T
20、he 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 system serves tocompe
21、nsate 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 diagonal fluorescen
22、ce, 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), nthematrix define
23、d 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 Donaldson radiance facto
24、r, 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 approximately equal t
25、o 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-cence” as a general t
26、erm, 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 bispectral matrix
27、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.3.2.11 off-diagona
28、l 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 and viewingwavebands
29、 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 identically irradiated a
30、nd 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 steps inthe calibr
31、ation 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, Queens Road, Ted
32、dington,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 National Institute o
33、f Standards and Technology (NIST), 100Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http:/www.nist.gov.E 2153 01 (2006)2when bispectral photometric measurements are required inspecific test methods or other documents.4.2 In this practice, the measuring instrument, a bispectrom-eter, is equippe
34、d 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 setting the irradi
35、ation 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 theDonaldson matrix (2), an
36、d 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 calculations using spect
37、ral 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 factor is aninstru
38、ment- 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, without the inaccura-ci
39、es 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 standards, and for
40、 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-son radiance facto
41、r 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 multiplebeams.6.1.2.2 For he
42、mispherical 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 bandpass.6.1.4 Identif
43、ication 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 designed for measurement
44、 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 monochromatic radia-t
45、ion 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 the UV and visible
46、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 from 300 to 780 nm
47、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 negligibly small for th
48、e 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 which data are obtai
49、ned.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-persive element and r
