1、Designation: C1510 01 (Reapproved 2012)Standard Test Method forColor and Color Difference of Whitewares by AbrigedSpectrophotometry1This standard is issued under the fixed designation C1510; the number immediately following the designation indicates the year oforiginal adoption or, in the case of re
2、vision, 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 measure-ment of the reflection properties and color of
3、 ceramic glazesand other whitewares by the use of a spectrophotometer orspectrocolorimeter with a hemispherical optical measuringsystem, such as an integrating sphere.1.2 The test method is suitable for use with most specimenshaving an exterior flat surface large enough to cover thespectrophotometer
4、 sample port.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.
5、 Referenced Documents2.1 ASTM Standards:2C242 Terminology of Ceramic Whitewares and RelatedProductsD2244 Practice for Calculation of Color Tolerances andColor Differences from Instrumentally Measured ColorCoordinatesE179 Guide for Selection of Geometric Conditions forMeasurement of Reflection and Tr
6、ansmission Properties ofMaterials3E284 Terminology of AppearanceE308 Practice for Computing the Colors of Objects byUsing the CIE SystemE805 Practice for Identification of Instrumental Methods ofColor or Color-Difference Measurement of MaterialsE1164 Practice for Obtaining Spectrometric Data forObje
7、ct-Color EvaluationE1331 Test Method for Reflectance Factor and Color bySpectrophotometry Using Hemispherical Geometry3. Terminology3.1 Definitions:3.1.1 The definitions in Guide E179, Terminologies C242and E284, and Practice E1164 are applicable to this testmethod.4. Summary of Test Method4.1 This
8、test method provides a procedure for measuring thereflectance factors of reflecting ceramic glazes or relatedwhiteware specimens by using a spectrophotometer or spec-trocolorimeter equipped with a hemispherical optical measur-ing system such as an integrating sphere. (See Test MethodE1331.)4.2 This
9、test method includes procedures for calibrating theinstrument and for selecting specimens suitable for precisionmeasurement.4.3 Most modern spectrophotometers have the capacity tocompute the color coordinates of the specimen immediatelyfollowing the measurement. When this is the case, the usermust s
10、elect the color system, observer, and illuminant (PracticeE308, Section 6).5. Significance and Use5.1 The most direct and accessible methods for obtainingthe color coordinates of ceramic glazes and related whitewaresare by instrumental measurement using spectrophotometers orcolorimeters with either
11、hemispherical or bidirectional opticalmeasuring systems. This test method provides procedures forsuch measurement by reflectance spectrophotometry using ahemispherical optical measuring system.5.2 This test method is especially suitable for measurementof the following types of specimens for the indi
12、cated uses(SeePractice E805.):1This test method is under the jurisdiction ofASTM Committee C21 on CeramicWhitewares and Related Products and is the direct responsibility of SubcommitteeC21.03 on Methods for Whitewares and Environmental Concerns.Current edition approved April 1, 2012. Published April
13、 2012. Originallyapproved in 2001. Last previous edition approved in 2007 as C151001(2007). DOI:10.1520/C1510-01R12.2For 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
14、the standards Document Summary page onthe ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.2.1 All types of ceramic glaze an
15、d related whitewarespecimens to obtain data for use in computer colorant formu-lation.5.2.2 Ceramic glaze and related whiteware specimens forcolor assessment.5.2.2.1 For the measurement of plane-surface high-glossspecimens, the specular component should generally be ex-cluded during the measurement.
16、5.2.2.2 For the measurement of plane-surface intermediate-gloss (satin) specimens, where the first-surface reflectioncomponent may be distributed over a wide range of angles,measurement may be made with the specular componentincluded, but the resulting color coordinates may not correlatebest with vi
17、sual judgments of the color. Measurement withspecular excluded may lead to better correlations.5.2.2.3 For the measurement of plane-surface, low-gloss(matte) specimens, the specular component may either beexcluded or included, as no significant difference in the resultsshould be apparent.5.3 An esti
18、mate of gloss may be obtained by measuring thereflection both with the specular component of reflectionincluded and excluded, and then calculating the differencebetween the two measurements at several wavelengths acrossthe visible spectrum, as described in 10.2.6. Apparatus6.1 Spectrophotometer or S
19、pectrocolorimeter, designed forthe measurement of color coordinates of reflecting specimensby use of integrating-sphere geometry.6.2 Calibration Standards, either supplied by the instrumentmanufacturer or obtained separately, as follows (PracticeE1164, Section 9):6.2.1 White Standard, of hemispheric
20、al reflectance factor(mandatory). (A standard of bidirectional reflectance factor isnot satisfactory and should not be used.)6.2.2 Calibration Standards, for (1) setting or verifying zeroon the photometric scale; (2) verifying the wavelength scale;and (3) evaluating stray light (optional).6.2.3 Veri
21、fication Standards, (recommended) (PracticeE1164, 9.5).7. Specimen Selection7.1 For highest precision and accuracy, select specimenswith the following properties:7.1.1 High visual uniformity and freedom from blemishes inthe area to be measured,7.1.2 Opaque specimens that have at least one exterior p
22、lanesurface sufficiently large to cover the sample port on thespectrophotometer, and7.1.3 Translucent and clear glaze specimens will give re-sults that come, at least in part, from the underlying substrate.8. Calibration and Verification8.1 Set the instrument for inclusion or exclusion of thespecula
23、r component of reflection; set it the same as will be usedin 8.4 (if carried out) or 9.1.8.2 Calibrate or verify the calibration of the following(Practice E1164, Section 9):8.2.1 Zero setting of the reflectance scale (mandatory), and8.2.2 Wavelength scale (recommended).8.3 Calibrate the full-scale v
24、alue of the reflectance scale ofthe instrument by use of the white reflectance standard (man-datory). This should be done every time the instrument isstarted up. Follow the instrument manufacturers instructions.8.4 Verify the accuracy of the instrumental data by measure-ment of a series of verificat
25、ion standards (recommended)(Practice E1164, 9.5). Select the appropriate color scales,observer, and illuminant for the computation of color coordi-nates before measurement.9. Procedure9.1 Select inclusion or exclusion of the specular componentof reflection.9.2 When required, select the color scales,
26、 observer, andilluminant for the computation of color coordinates (PracticeE308, Section 6). For most applications, the CIELAB (L*, a*,b*) color scale, 10 observer, and D65illuminant is recom-mended.9.3 Select other options, such as wavelength range andinterval, when required. Follow instrument manu
27、facturersinstructions or specified procedures.9.4 Handle the specimen carefully; avoid touching the areato be measured. When necessary, clean the specimen by usingan agreed procedure. Glazed specimens should be washed withsoap and water, and dried before measurement.9.5 Place the specimen against th
28、e reflectance measurementport of the integrating sphere.9.6 Measure the specimen, following the instrument manu-facturers instructions. When areas of high visual uniformityand freedom from blemishes cannot be found, make severalmeasurements over the area of interest, and average the results.9.7 For
29、color difference, also measure the standard to becompared against.9.8 If an indication of gloss is desired, measure the speci-men both with specular reflectance included and excluded.Many instruments will require recalibration when changingfrom specular reflectance included to specular reflectanceex
30、cluded, or vice-versa.9.9 Transcribe the data required for the report, when notprinted by the instrument.10. Calculations10.1 Perform calculation of the CIELAB color coordinates,and any desired calculations of color coordinates that are notmade automatically by the instrument (Test Method D2244 andP
31、ractice E308).10.2 For an indication of gloss, calculate the differencebetween reflectance with specular included and reflectancewith specular excluded at 16 equally spaced wavelengths overthe visible spectrum, and then average the results.10.3 For color difference, calculate:D E* 5 D L*!21 D a*!21
32、D b*!2#12 (1)where:D L* =L*sampleL*standardD a* =a*samplea*standardC1510 01 (2012)2D b* =b*sampleb*standard10.4 The direction of the color difference is described by themagnitude and algebraic signs of the components D L*, D a*,and D b*, which have the following approximate meanings:+ D L* = lighter
33、 D L* = darker+ D a* = redder (less green) D a* = greener (less red)+ D b* = yellower (less blue) D b* = bluer (less yellow)11. Report11.1 Report the following information:11.1.1 Specimen description,11.1.2 Instrument used,11.1.3 Date of measurement,11.1.4 Instrument parameters selected in 9.1-9.4,1
34、1.1.5 Measurement results, in the form of tables of reflec-tance factor versus wavelength or color-scale values,11.1.6 CIELAB color coordinates, and11.1.7 If desired, the indication of gloss level.11.1.8 For color difference, report delta E*, and direction ifdesired.12. Precision and Bias12.1 Precis
35、ion:12.1.1 RepeatabilityResults reported in the literature,4obtained by the use of modem measuring instruments, ex-pressed in terms of CIELAB color differences (see PracticeE308) are within 0.1 units. On this scale, the smallest colordifference that can be reliably observed is of the order of 0.5uni
36、ts, commercial color tolerances range upward from aboutone unit.12.1.2 ReproducibilityThe reproducibility within a groupof similar instruments was reported to be about 0.2 units.5Inter-instrument agreement comparing different types of instru-ments, especially if different types of illuminating and v
37、iewingconditions are involved, is likely to be an order of magnitudepoorer.12.2 Two measurements should be considered suspect ifthey differ by more than the previous figures applicable to thetwo measurements.13. Keywords13.1 color; hemispherical geometry; reflectance; reflectancefactor; spectrophoto
38、metryASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights
39、, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional st
40、andardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Co
41、mmittee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveadd
42、ress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).4Billmeyer, F.W. Jr., and Alessi, P.J., “Assessment of Color-Measuring Instru-ments,” Color Research and Application, Vol 6, 1981, pp. 195202.5Stanziola, R., Momeroff, B., and Hemmendinger, H., “The SpectroSensorANew Generation Spectrophotometer,” Color Research and Application, Vol 4, 1979,pp. 157163.C1510 01 (2012)3
