1、Designation: E3040 16E3040 18Standard Practice forEvaluation of Instrumental Color Difference with a GrayScale1This standard is issued under the fixed designation E3040; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of l
2、ast 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 Test Method D2616 describes a painted gray scale and the procedure to be used in the visual evaluation of color differe
3、nceson non-self-luminous materials by comparison to this scale. This practice provides an alternative method of obtaining a similarlyvalued result by an instrumental method.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard,e
4、xcept that the test results of this test method are converted by the calculations to an arbitrary visual scale defined by Test MethodD2616, whose units are called GSC (Gray Scale for Change in Color).1.3 This standard does not purport to address all of the safety concerns, if any, associated with it
5、s use. It is the responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recogni
6、zed principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D2244 Practice for Calcul
7、ation of Color Tolerances and Color Differences from Instrumentally Measured Color CoordinatesD2616 Test Method for Evaluation of Visual Color Difference With a Gray ScaleE284 Terminology of AppearanceE308 Practice for Computing the Colors of Objects by Using the CIE SystemE1164 Practice for Obtaini
8、ng Spectrometric Data for Object-Color Evaluation2.2 ISO Standards:3ISO 105-A05 TextilesTests for ColorfastnessPart A05 Instrumental assessment of change in colour for determination ofgrey scale rating2.3 AATCC Standards:4AATCC Evaluation Procedure 7 Instrumental Assessment of the Change in Color of
9、 a Test Specimen2.4 JIS Standards:5JIS L 0809 Instrumental determination of colour fastness Change in colour and staining3. Terminology3.1 Definitions:3.1.1 Definitions of appearance terms in Terminology E284 are applicable to this test method.3.2 Definitions of Terms Specific to This Standard:1 Thi
10、s practice is under the jurisdiction of ASTM Committee E12 on Color and Appearance and is the direct responsibility of Subcommittee E12.04 on Color andAppearance Analysis.Current edition approved July 1, 2016March 1, 2018. Published July 2016April 2018. Originally approved in 2015. Last previous edi
11、tion approved in 20152016 as E3040 15.16. DOI: 10.1520/E3040-16.10.1520/E3040-18.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page
12、on the ASTM website.3 Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.4 Available from American Association of Textile Chemists and Colorists (AATCC), P.O. Box 12215, Research Triangle Park, NC 27709-2215, http:/www.aatcc
13、.org.5 Available from Japanese Standards Association (JSA), Mita MT Bldg., 3-13-12 Mita, Minato-ku, Tokyo 108-0073, Japan, http:/www.jsa.or.jp.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 previo
14、us version. Becauseit may not be technically possible to 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 Inte
15、rnational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2.1 color change, na change in color of any kind whether in lightness, hue, or chroma or any combination of these,discernible by comparing the test specimen with a corresponding untested specimen.3.2.2 g
16、ray scale grade, GSC, nfor color change, the numerical value that is assigned to the change in color of a test specimenas compared to an original or untreated specimen.4. Summary of Test Method4.1 The color of a specimen that has been submitted to a test whose severity is evaluated by change in colo
17、r, and an identicaluntreated specimen, are measured spectrophotometrically and both of their colors evaluated by conventional means. Theconventional color difference attributes are converted to a Gray Scale for Color Change by a series of calculations.4.2 This practice is similar to the following th
18、ree international methods: AATCC Evaluation Procedure 7, ISO 105-A05, andJIS L 0809.5. Significance and Use5.1 The gray scale grade GSC is useful to evaluate the color difference of any pair of colors that have been subjected to a testwhose severity of result is nominated by color difference of the
19、treated member to the untreated member. This includes, but is notlimited to, scrub tests, exterior exposures, crocking tests, blocking tests, certain abrasion tests, and color transfer tests.5.2 A major advantage of the instrumental method of obtaining gray scale grades is that under the visual meth
20、od substantialscreening and training of the operators in visual color assessment is required. No such burden is placed on the operators in thisinstrumental method.5.3 The method is usually not used for staining tests which have their own gray scale for staining.6. Apparatus6.1 Spectrophotometer, hav
21、ing one of the three qualified geometries that are listed in Practice E1164. These geometries include:bidirectional (more familiarly called 0/45 or 45/0), or hemispherical specular included, or hemispherical specular excludedgeometries.6.2 In the absence of any reason for choosing one over the other
22、, hemispherical specular included geometry is most appropriatefor the type of measurements that are made in connection with this standard.7. Sampling, Test Specimens, and Test Units7.1 The specimen pairs used in this practice are nearly always a pair of identical specimens where one member of the pa
23、ir hasbeen subjected to a test whose severity of result may be quantified by a change in color.7.2 The practice is based upon a visual method D2616 of assessing the degree of this color change. The precision of the visualmethod is such that the gray scale grade is reported to the nearest half-unit o
24、n a scale of five to one. This method is designed toemulate the results of Test Method D2616 and as such is reported in these same half-units.8. Calibration and Standardization8.1 Maintain the spectrophotometer in a state of calibration. Standardize the spectrophotometer in accordance with themanufa
25、cturers instructions, or follow the standardization practices of Practice E1164.9. Procedure9.1 Measure the color of the reference specimen and calculate the CIELAB L*, a*, b*, C* and h values using the data for the10 observer and for illuminant D65.9.2 Measure the color of the test specimen which h
26、as been subjected to the colorfastness test and make the same colorimetriccalculations as done for the reference specimen. Then make the calculations as described in Annex A1.10. Calculation or Interpretation of Results10.1 A complete description of the calculations, the symbols and subscripts used
27、in them, is given in Annex A1 of this method.10.2 The results of the method derive GSC values that are in half-steps between five and a value of unity. These values forma scale of discrete steps. An alternative continuous scale in Table A1.1 is equivalent and may be used at the users option. Theroun
28、ded value GSC may be used as an index in the left-hand column to look-up the equivalent alternative continuous value in theright-hand column.11. Report11.1 Report the following information:11.1.1 A complete description of the test pair and the treatment being evaluated by the destructive test;E3040
29、18211.1.2 The calculated value of GSC calculated in connection with this sample pair;11.1.3 The make, model, and serial number of the spectrophotometer used to make the spectral measurements, and the geometryof the instrument, bidirectional or hemispherical. If the geometry is hemispherical, state w
30、hether specular included or specularexcluded mode was employed;11.1.4 A statement that D65 and the 10 Observer were used to calculate the conventional colorimetric values, or, if a customilluminant-observer was employed, which one, and a justification for that deviation from the standard method.12.
31、Precision and Bias12.1 PrecisionThe practice does not in itself contribute to uncertainty of measurement, but rather converts the scale of theresult, and with it the certainty, from that of CIELAB to GSC.12.2 BiasNo information can be provided about the bias of the test method for measuring GSC beca
32、use no material havingan accepted reference value is available.13. Keywords13.1 color difference; gray scale; instrumental color-differenceANNEX(Mandatory Information)A1. SYMBOLS AND CALCULATIONSA1.1 SymbolsA1.1.1 The following subscripts are used in connection with the symbols of A1.1.2.ab nominate
33、s that the scripted symbol is associated with the CIELAB color-difference equation (see Practice D2244).F nominates that the scripted symbol is a special-case color difference component for Gray Scale for change in color, and thusdiffers in value from its CIELAB counterpart.K nominates that the scri
34、pted symbol has been chroma corrected, and thus differs in value from its CIELAB counterpart.M nominates the mean value of the scripted symbol between the test specimen and the reference specimen.R nominates that the scripted symbol is associated with the reference specimen.T nominates that the scri
35、pted symbol is associated with the test specimen.A1.1.2 The following symbols are used in the calculations:D = a place-holder for a chroma correction coefficienth = a hue angle; as used in these equations the values are always in degrees, never radians. 2pi radians are equal to 360 degrees.x = a pla
36、ce-holder for a calculated exponent in the special E equationsC = chroma differenceE = total color-differenceH = hue differenceL = lightness differenceG = a place-holder for the unrounded value of the color differenceA1.2 CalculationsA1.2.1 The following instructions define the calculations:A1.2.1.1
37、 Calculate L*, a*, b*, hab, and C*ab of both the reference and the trial specimens in accordance with Practice E308, orPractice D2244, whose instructions are identical to each other.if Abs (hab,T hab,R) 180 thenhM = (hab,T + hab,R)/2elseE3040 183if Abs(hab,T + hab,R) 360 thenhM = (hab,T + hab,R)/2 +
38、 180elsehM = (hab,T + hab,R)/2 + 180end ifend ifif Abs(hM 280) 180 thenx = (hM 280)/302elsex = (360 Abs (hM 280)/302end ifL* = L*ab,T L*ab,RC*ab = C*ab,T C*ab,RCM = (C*ab,T + C*ab,R)/2D = (C*ab CM ex)/100E*ab = (L*)2 + (a*)2 + (b*)21/2H*ab = (E*ab)2 (L*)2 (C*ab)21/2CK = C*ab DHK = H*ab DCF = CK/1 +
39、(10(20 CM/1000)2HF = HK/1 + (20(10 CM/1000)2EF = (L*)2 + (CF)2 (HF)21/2if EF 3.4 thenG = 5 EF/1.7elseif EF 16.15 thenG = 5 Log2(EF/0.85)elseG = 1end ifend ifE3040 184GSC = Int(2 G + 0.5)/2A1.2.1.2 Gray Scale Color Change TableSee Table A1.1.A1.2.1.3 If the computer language used to invoke these equa
40、tions does not contain a log2 function, the following relationship willbe useful:log2X! 5log10X!log102!5lognX!logn2!(A1.1)where n refers to any base of a logarithm including that of natural logarithms.APPENDIX(Nonmandatory Information)X1. EXAMPLE CALCULATIONS FOR GRAY SCALE CHANGE IN COLORX1.1 If Ta
41、ble X1.1 is used to check a computer program, discrepancies of 60.001 or occasionally 60.002, may arise due toround-off, and do not call into question the programs correctness.TABLE A1.1 Gray Scale for Color Change Alternate ScalesDiscrete Scale Continuous Scale5 54.5 454 43.5 343 32.5 232 21.5 121
42、1TABLE X1.1 Example Calculations for Gray Scale for Change in ColorParam. STD-1 BAT-1 STD-2 BAT-2 STD-3 BAT-3 STD-4 BAT-4X 15.1424 16.5034 27.3479 30.3034 41.4470 46.5670 10.8819 12.7887Y 18.8150 20.2601 25.5809 31.4791 44.1071 48.6131 11.6227 13.2315Z 23.0409 24.0848 31.3580 33.0023 49.6602 54.9176
43、 10.8808 15.0329L* 50.47 52.13 60.41 62.91 72.30 75.21 40.61 43.11a* -15.23 -14.49 1.01 1.73 -1.13 1.35 -1.02 1.64b* -5.16 -4.08 -0.98 1.05 -2.46 -2.72 4.34 -1.96Cab 16.08 15.05 1.41 2.02 2.71 3.04 4.46 2.56h 198.72 195.73 224.14 31.26 245.33 296.40 103.23 309.92HM 197.22 307.70 270.86 26.57x 7.61 0
44、.85 0.09 12.62L*ab 1.66 2.50 2.91 2.50C*ab -1.03 0.62 0.33 -1.90CM 15.57 1.72 2.87 3.51D -0.0001 0.0045 0.0086 0.0000E*ab 2.11 3.30 3.83 7.28H*ab 0.81 2.06 2.47 6.57CK -1.03 0.61 0.32 -1.90HK 0.81 2.06 2.46 6.57CF -1.00 0.61 0.32 -1.90HF 0.74 2.06 2.46 6.54EF 2.08 3.30 3.85 7.25G 3.78 3.06 2.83 1.91
45、GSC 4.00 3.00 3.00 2.00E3040 185ASTM 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
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