1、Designation: E1331 09E1331 15Standard Test Method forReflectance Factor and Color by Spectrophotometry UsingHemispherical Geometry1This standard is issued under the fixed designation E1331; the number immediately following the designation indicates the year oforiginal adoption or, in the case of rev
2、ision, 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.1. Scope1.1 This test method describes the instrumental measurement of the reflection properties and color of o
3、bject-color specimensby the use of a spectrophotometer or spectrocolorimeter with a hemispherical optical measuring system, such as an integratingsphere.1.2 The test method is suitable for use with most object-color specimens. However, it should not be used for retroreflectivespecimens or for fluore
4、scent specimens when highest accuracy is desired. Specimens having intermediate-gloss surfaces shouldpreferably not be measured by use of this geometry.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4 This standard does
5、 not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standar
6、ds:2D2244 Practice for Calculation of Color Tolerances and Color Differences from Instrumentally Measured Color CoordinatesE179 Guide for Selection of Geometric Conditions for Measurement of Reflection and Transmission Properties of MaterialsE284 Terminology of AppearanceE308 Practice for Computing
7、the Colors of Objects by Using the CIE SystemE805 Practice for Identification of Instrumental Methods of Color or Color-Difference Measurement of MaterialsE991 Practice for Color Measurement of Fluorescent Specimens Using the One-Monochromator MethodE1164 Practice for Obtaining Spectrometric Data fo
8、r Object-Color EvaluationE1345 Practice for Reducing the Effect of Variability of Color Measurement by Use of Multiple Measurements3. Terminology3.1 Definitions:3.1.1 The definitions in Guide E179, Terminology E284, and Practice E1164 are applicable to this test method.4. Summary of Test Method4.1 T
9、his test method provides a procedure for measuring the reflectance factors of reflecting object-color specimens by usinga spectrophotometer or spectrocolorimeter equipped with a hemispherical optical measuring system such as an integrating sphere.4.2 This test method includes procedures for calibrat
10、ing the instrument and for selecting specimens suitable for precisionmeasurement.4.3 Most modern spectrophotometers have the capacity to compute the color coordinates of the specimen immediatelyfollowing the measurement. When this is the case, the user must select the color system, observer, and ill
11、uminant (see PracticeE308, Procedure).1 This test method is under the jurisdiction of ASTM Committee E12 on Color and Appearance and is the direct responsibility of Subcommittee E12.02 onSpectrophotometry and Colorimetry.Current edition approved Dec. 1, 2009July 1, 2015. Published December 2009July
12、2015. Originally approved in 1990. Last previous edition approved in 20042009 asE1331 04.E1331 09. DOI: 10.1520/E1331-09.10.1520/E1331-15.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume i
13、nformation, refer to the standardsstandards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to
14、adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Consh
15、ohocken, PA 19428-2959. United States15. Significance and Use5.1 The most direct and accessible methods for obtaining the color coordinates of object colors are by instrumental measurementusing spectrophotometers or colorimeters with either hemispherical or bidirectional optical measuring systems. T
16、his test methodprovides procedures for such measurement by reflectance spectrophotometry using a hemispherical optical measuring system.5.2 This test method is especially suitable for measurement of the following types of specimens for the indicated uses (GuideE179 and Practice E805):5.2.1 All types
17、 of object-color specimens to obtain data for use in computer colorant formulation.5.2.2 Object-color specimens for color assessment.5.2.2.1 For the measurement of plane-surface high-gloss specimens, the specular component should generally be excludedduring the measurement.5.2.2.2 For the measuremen
18、t of plane-surface intermediate-gloss specimens and of textured-surface specimens, includingtextiles, where the first-surface reflection component may be distributed over a wide range of angles, measurement may be madewith the specular component included, but the resulting color coordinates may not
19、correlate best with visual judgments of the color.The use of bidirectional geometry, such as 45/0 or 0/45, may lead to better correlations.5.2.2.3 For the measurement of plane-surface, low-gloss (matte) specimens, the specular component may either be excluded orincluded, as no significant difference
20、 in the results should be apparent.5.2.3 Specimens with bare metal surfaces for color assessment. For this application, the specular component should generallybe included during the measurement.5.3 This test method is not recommended for measurement of the following types of specimens, for which the
21、 use ofbidirectional measurement geometry (0/45 or 45/0) is preferable (Guide E179):5.3.1 Object-color specimens of intermediate gloss,5.3.2 Retroreflective specimens, and5.3.3 Fluorescent specimens (Practice E991).5.3.3.1 When there is doubt as to whether the specular component of reflection should
22、 be included or excluded, bothmeasurements should be made, and the results correlated with visual judgments. Thereafter, the method with higher visualcorrelation should be utilized.5.3.3.2 When measurements of two specimens whose gloss, or texture, are substantially different from each other, are to
23、 beutilized in a color-difference comparison, generally the specular component should be included in each measurement. This has theeffect of including in both measurements all the first surface reflections whether diffuse or specular. These first surface reflectionsare subtracted from each other in
24、the color-difference equation, and differences in the body color remain, which is what is usuallysought.6. Apparatus6.1 Spectrophotometer or spectrocolorimeter, designed for the measurement of color coordinates of reflecting specimens by useof integrating-sphere geometry.6.2 Calibration standards, e
25、ither supplied by the instrument manufacturer or obtained separately, as follows (Practice E1164,Standardization and Material Standards):6.2.1 White standard, of hemispherical reflectance factor (mandatory). (A standard of bidirectional reflectance factor is notsatisfactory and should not be used.)6
26、.2.2 Calibration standards, for (1) setting or verifying zero on the photometric scale; (2) verifying the wavelength scale; and(3) evaluating stray light (optional).6.2.3 Verification standards, (recommended) (Practice E1164, Standardization and Material Standards).7. Specimen Selection7.1 For highe
27、st precision and accuracy, select specimens with the following properties:7.1.1 High material uniformity and freedom from blemishes in the area to be measured,7.1.2 Opaque specimens that have at least one plane surface, and7.1.3 Translucent specimens that have two essentially plane and parallel surf
28、aces and that have a standard thickness, when oneis specified (Practice E1164, Test Specimens).8. Calibration and Verification8.1 Set the instrument for inclusion or exclusion of the specular component of reflection; set the same as will be used in 8.4(if carried out) or 9.1.8.2 Calibrate or verify
29、the calibration of the following (Practice E1164, Standardization and Material Standards):8.2.1 Zero setting of the reflectance scale (mandatory),8.2.2 Wavelength scale (recommended), andE1331 1528.2.3 Stray-light level (optional).8.3 Calibrate the full-scale value of the reflectance scale of the in
30、strument by use of the white reflectance standard (mandatory).Follow the instrument manufacturers instructions.8.4 Verify the accuracy of the instrumental data by measurement of a series of verification standards (recommended) (PracticeE1164, Standardization and Material Standards). Select the appro
31、priate color scales, observer, and illuminant for the computationof color coordinates before measurement.NOTE 1If the verification standards require a different selection of including or excluding the specular component than does 9.1, select the appropriatecondition for measurement of the verificati
32、on standards in 8.1, complete 8.4; select the correct setting for specimen measurement (9.1), repeat 8.3, andproceed to 9.2.9. Procedure9.1 Select inclusion or exclusion of the specular component of reflection (5.2).9.2 When required, select the color scales, observer, and illuminant for the computa
33、tion of color coordinates (see Practice E308,Procedure).9.3 Select other options, such as wavelength range and interval, when required. Follow instrument manufacturers instructionsor specified procedures.9.4 If the specimen is translucent, select specified black or white backing material. See Practi
34、ce E1164, Test Specimens, forfurther instructions on measuring translucent specimens.9.5 Handle the specimen carefully; avoid touching the area to be measured. When necessary, clean the specimen by using anagreed procedure.9.6 Place the specimen, with backing material if required, against the reflec
35、tance measurement port of the integrating sphere.9.7 Measure the specimen, following the instrument manufacturersmanufacturers instructions.9.8 Transcribe the data required for the report, when not printed by the instrument.10. Calculations10.1 Perform any desired calculations of color coordinates t
36、hat are not made automatically by the instrument (Practice D2244and Practice E308).11. Report11.1 Report the following information:11.1.1 Specimen description (Practice E1164, Report),11.1.2 Date of measurement,11.1.3 Instrument parameters selected in 9.1 9.4, and11.1.4 Measurement results, in the f
37、orm of tables of reflectance factor versus wavelength or color-scale values.12. Precision and Bias12.1 PrecisionThe interlaboratory study leading to the results expressed in this precision and bias statement was conductedby a Task Group in Subcommittee E12.93 on Precision and Bias during the period
38、July to September 2003. The results in 12.1.2and 12.1.4 were obtained by bootstrap procedures. The statistical confidence intervals computed using these procedures wereobtained from standard deviations obtained by resampling the variance distribution rather than by directly calculating the standardd
39、eviation of the measurements by conventional means.TABLE 1 Specimens, Colorimetric Values, and 95 %Reproducibility LimitsSample # Mean L* Mean a* Mean b* 95 % ReproducibilityLimits in units of E*abSample # Mean L* Mean a* Mean b* 95 % ReproducibilityLimits in units of E*abA01 41.90 4.89 -13.97 0.35C
40、01 70.00 23.36 -10.20 0.75A11 63.62 18.84 6.78 0.54C11 85.38 1.40 50.42 0.76E1331 15312.1.1 Repeatability SamplesThe specimens tested consisted of twelve neutral and colored, high gloss ceramic tiles,BCRA/Ceram Series II. The instrument population consisted of six different instruments in one labora
41、tory. Each specimen wasmeasured ten times on each instrument with the specular component included. Color difference comparisons were made onlybetween measurements of each tile made on the same instrument. The underlying data are known as the 2003 SCAI data from theMunsell Color Science Laboratory.12
42、.1.2 RepeatabilityRepeatability conditions are defined as measurements made in the same laboratory using the same testmethod by the same operator using the same equipment in the shortest possible period of time using specimens taken from onelot of homogeneous material. Two test results obtained unde
43、r repeatability conditions should be considered suspect to a 95 %repeatability limit if their values differ by more than 0.08 unit, E*ab.12.1.3 Reproducibility SamplesThe Collaborative Testing ServicesServices Color and Color-Difference CollaborativeReference Program has surveyed the precision of co
44、lor and color-difference measurements by sending out pairs of painted chipsexhibiting small color differences on a quarterly basis since 1971. The specimens of these surveys consist of opaque matte paintcoated on white sealed paper stock and are distributed to the respondents from the same lot of ho
45、mogeneous material. Thespecimens are specifically designed to be insensitive to the specular conditions present in the instrument, and no attempt is madeto report the possible geometric conditions under which the measurements are made. Table 1 reports results from four specimensfrom these survey ove
46、r the two-year period from 2000 to 2002. Approximately 250 instruments are reported in each survey. Theinstrument population of one of these four surveys consisted of 55 different models from nine different commercial instrumentmanufacturers. The most frequently reported instrument model accounted f
47、or 24 % of the population of instruments. The top fourinstruments accounted for 47 % of the population, and there were 25 instruments that represented a singular entry of that modelin this population.12.1.4 ReproducibilityReproducibility conditions are defined as measurements made in different labor
48、atories using differentequipment using the same test method, each by a different operator using specimens taken from one lot of homogeneous material.Two test results made under reproducibility conditions should be considered suspect to a 95 % reproducibility limit if their valuesdiffer by more than
49、the values given in Table 1 under the column headed “95 % Reproducibility Limits.”12.2 BiasIt is not possible to determine the bias, if any, of this test method because no accepted reference values are availablefor the specimens tested.12.3 The precision statistics for this test method must not be treated as exact mathematical quantities that are applicable to allinstruments, uses, and materials. There will be times when differences occur that are greater than those which would be predictedby the interlaboratory study leading to these results. Sometimes thes
