1、Designation: C 1510 01 (Reapproved 2007)Standard Test Method forColor and Color Difference of Whitewares by AbrigedSpectrophotometry1This standard is issued under the fixed designation C 1510; 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.1. Scope1.1 This test method describes the instrumental measure-ment of the reflection properties and color
3、 of 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 thespectrophotome
4、ter 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
5、.2. Referenced Documents2.1 ASTM Standards:2C 242 Terminology of Ceramic Whitewares and RelatedProductsD 2244 Practice for Calculation of Color Tolerances andColor Differences from Instrumentally Measured ColorCoordinatesE 179 Guide for Selection of Geometric Conditions forMeasurement of Reflection
6、and Transmission Properties ofMaterialsE 284 Terminology of AppearanceE 308 Practice for Computing the Colors of Objects byUsing the CIE SystemE 805 Practice for Identification of Instrumental Methods ofColor or Color-Difference Measurement of MaterialsE 1164 Practice for Obtaining Spectrometric Dat
7、a forObject-Color EvaluationE 1331 Test Method for Reflectance Factor and Color bySpectrophotometry Using Hemispherical Geometry3. Terminology3.1 Definitions:3.1.1 The definitions in Guide E 179, Terminologies C 242and E 284, and Practice E 1164 are applicable to this testmethod.4. Summary of Test M
8、ethod4.1 This 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 MethodE
9、1331.)4.2 This 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,
10、 the usermust select the color system, observer, and illuminant (PracticeE 308, 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 orcolorimet
11、ers with either 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 specim
12、ens for the indicated uses(SeePractice E 805.):5.2.1 All types of ceramic glaze and related whitewarespecimens to obtain data for use in computer colorant formu-lation.5.2.2 Ceramic glaze and related whiteware specimens forcolor assessment.1This test method is under the jurisdiction ofASTM Committee
13、 C21 on CeramicWhitewares and Related Products and is the direct responsibility of SubcommitteeC21.03 on Methods for Whitewares and Environmental Concerns.Current edition approved May 1, 2007. Published May 2007. Originallyapproved in 2001. Last previous edition approved in 2001 as C 151001.2For ref
14、erenced 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 Drive, PO Box C700, We
15、st Conshohocken, PA 19428-2959, United States.5.2.2.1 For the measurement of plane-surface high-glossspecimens, the specular component should generally be ex-cluded during the measurement.5.2.2.2 For the measurement of plane-surface intermediate-gloss (satin) specimens, where the first-surface refle
16、ctioncomponent 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 visual judgments of the color. Measurement withspecular excluded may lead to better correlations.5.2.2.3 For the m
17、easurement 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 estimate of gloss may be obtained by measuring thereflection both with the specular component of reflectionincluded
18、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 Spectrocolorimeter, designed forthe measurement of color coordinates of reflecting specimensby use of integrating
19、-sphere geometry.6.2 Calibration Standards, either supplied by the instrumentmanufacturer or obtained separately, as follows (PracticeE 1164, Section 9):6.2.1 White Standard, of hemispherical reflectance factor(mandatory). (A standard of bidirectional reflectance factor isnot satisfactory and should
20、 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 Verification Standards, (recommended) (PracticeE 1164, 9.5).7. Specimen Selection7.1 For highest precision and accu
21、racy, 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 planesurface sufficiently large to cover the sample port on thespectrophotometer, and7.1.3 Translucent and clea
22、r 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 thespecular component of reflection; set it the same as will be usedin 8.4 (if carried out) or 9.1.8.2 Calibrate or veri
23、fy the calibration of the following(Practice E 1164, Section 9):8.2.1 Zero setting of the reflectance scale (mandatory), and8.2.2 Wavelength scale (recommended).8.3 Calibrate the full-scale value of the reflectance scale ofthe instrument by use of the white reflectance standard (man-datory). This sh
24、ould 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 verification standards (recommended)(Practice E 1164, 9.5). Select the appropriate color scales,observer, and illumina
25、nt 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, observer, andilluminant for the computation of color coordinates (PracticeE 308, Section 6). For most appli
26、cations, 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 manufacturersinstructions or specified procedures.9.4 Handle the specimen carefully; avoid touching the areato
27、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 the reflectance measurementport of the integrating sphere.9.6 Measure the specimen, following the instrument
28、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 color difference, also measure the standard to becompared against.9.8 If an indication of gloss is desired,
29、 measure the speci-men both with specular reflectance included and excluded.Many instruments will require recalibration when changingfrom specular reflectance included to specular reflectanceexcluded, or vice-versa.9.9 Transcribe the data required for the report, when notprinted by the instrument.10
30、. 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 D 2244and Practice E 308).10.2 For an indication of gloss, calculate the differencebetween reflectance with specular
31、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 D b*!2#12 (1)where:D L* =L*sampleL*standardD a* =a*samplea*standardD b* =b*sampleb*standard10.4 The direc
32、tion 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* = lighterC 1510 01 (2007)2 D L* = darker+ D a* = redder (less green) D a* = greener (less red)+ D b* = yellower (less blue) D b* =
33、 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 9.1-9.4,11.1.5 Measurement results, in the form of tables of reflec-tance factor versus wavelength or color-scale
34、 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 Precision:12.1.1 RepeatabilityResults reported in the literature,3obtained by the use of modem measuring instr
35、uments, ex-pressed in terms of CIELAB color differences (see PracticeE 308) are within 0.1 units. On this scale, the smallest colordifference that can be reliably observed is of the order of 0.5units, commercial color tolerances range upward from aboutone unit.12.1.2 ReproducibilityThe reproducibili
36、ty within a groupof similar instruments was reported to be about 0.2 units.4Inter-instrument agreement comparing different types of instru-ments, especially if different types of illuminating and viewingconditions are involved, is likely to be an order of magnitudepoorer.12.2 Two measurements should
37、 be considered suspect ifthey differ by more than the previous figures applicable to thetwo measurements.13. Keywords13.1 color; hemispherical geometry; reflectance; reflectancefactor; spectrophotometryASTM International takes no position respecting the validity of any patent rights asserted in conn
38、ection 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, are entirely their own responsibility.This standard is subject to revision at any time by the respons
39、ible 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 standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful c
40、onsideration 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 Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 10
41、0 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 aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM w
42、ebsite(www.astm.org).3Billmeyer, F.W. Jr., and Alessi, P.J., “Assessment of Color-Measuring Instru-ments,” Color Research and Application, Vol 6, 1981, pp. 195202.4Stanziola, R., Momeroff, B., and Hemmendinger, H., “The SpectroSensorANew Generation Spectrophotometer,” Color Research and Application, Vol 4, 1979,pp. 157163.C 1510 01 (2007)3
