1、Designation: E3040 15Standard Test Method 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 last r
2、evision. 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 andthe procedure to be used in the visual evaluation of colordifferences on
3、 non-self-luminous materials by comparison tothis scale. This test method provides an alternative method ofobtaining a similarly valued result by an instrumental method.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard, except
4、 that the test results of this test method areconverted by the calculations to an arbitrary visual scaledefined by Test Method D2616, whose units are called GSC(Gray Scale for Change in Color).1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. I
5、t 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. Referenced Documents2.1 ASTM Standards:2D2244 Practice for Calculation of Color Tolerances andColor Differences from In
6、strumentally Measured ColorCoordinatesD2616 Test Method for Evaluation of Visual Color Differ-ence With a Gray ScaleE284 Terminology of AppearanceE308 Practice for Computing the Colors of Objects by Usingthe CIE SystemE1164 Practice for Obtaining Spectrometric Data for Object-Color Evaluation2.2 ISO
7、 Standards:3ISO 105-A05 TextilesTests for ColorfastnessPart A05Instrumental assessment of change in colour for determi-nation of grey scale rating2.3 AATCC Standards:4AATCC Evaluation Procedure 7 Instrumental Assessment ofthe Change in Color of a Test Specimen2.4 JIS Standards:5JIS L 0809 Instrument
8、al determination of colour fastness Change in colour and staining3. Terminology3.1 Definitions:3.1.1 Definitions of appearance terms in Terminology E284are applicable to this test method.3.2 Definitions of Terms Specific to This Standard:3.2.1 color change, na change in color of any kindwhether in l
9、ightness, hue, or chroma or any combination ofthese, discernible by comparing the test specimen with acorresponding untested specimen.3.2.2 gray scale grade, GSC, nfor color change, thenumerical value that is assigned to the change in color of a testspecimen as compared to an original or untreated s
10、pecimen.4. Summary of Test Method4.1 The color of a specimen that has been submitted to adestructive test whose severity is evaluated by change in color,and an identical untreated specimen, are measured spectropho-tometrically and both of their colors evaluated by conventionalmeans. The conventional
11、 color difference attributes are con-verted to a Gray Scale for Color Change by a series ofcalculations.1This test method is under the jurisdiction of ASTM Committee E12 on Colorand Appearance and is the direct responsibility of Subcommittee E12.04 on Colorand Appearance Analysis.Current edition app
12、roved Nov. 1, 2015. Published December 2015. DOI:10.1520/E3040-15.2For 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 web
13、site.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.4Available from American Association of Textile Chemists and Colorists(AATCC), P.O. Box 12215, Research Triangle Park, NC 27709-2215, http:/www.aatcc.org.5Available fro
14、m Japanese Standards Association (JSA), Mita MT Bldg., 3-13-12Mita, Minato-ku, Tokyo 108-0073, Japan, http:/www.jsa.or.jp.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14.2 This test method is similar to the following threeinternatio
15、nal test methods: AATCC Evaluation Procedure 7,ISO 105-A05, and JIS L 0809.5. Significance and Use5.1 The gray scale grade GSCis useful to evaluate the colordifference of any pair of colors that have been subjected to adestructive test whose severity of result is nominated by colordifference of the
16、treated member to the untreated member. Thisincludes, but is not limited to, scrub tests, exterior exposures,crocking tests, blocking tests, certain abrasion tests, and colortransfer tests.5.2 A major advantage of the instrumental method ofobtaining gray scale grades is that under the visual methods
17、ubstantial screening and training of the operators in visualcolor assessment is required. No such burden is placed on theoperators in this instrumental method.5.3 The method is usually not used for staining tests whichhave their own gray scale for staining.6. Apparatus6.1 Spectrophotometer, having o
18、ne of the three qualifiedgeometries that are listed in Practice E1164. These geometriesinclude: bidirectional (more familiarly called 0/45 or 45/0),or hemispherical specular included, or hemispherical specularexcluded geometries.6.2 In the absence of any reason for choosing one over theother, hemisp
19、herical specular included geometry is most ap-propriate for the type of measurements that are made inconnection with this standard.7. Sampling, Test Specimens, and Test Units7.1 The specimen pairs utilized in this method are nearlyalways a pair of identical specimens where one member of thepair has
20、been subjected to a destructive test whose severity ofresult may be quantified by a change in color.7.2 The test is based upon a visual method D2616 ofassessing the degree of this color change. The precision of thevisual method is such that the gray scale grade is reported tothe nearest half-unit on
21、 a scale of five to one. This method isdesigned to emulate the results of Test Method D2616 and assuch 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 themanufactu
22、rers instructions, or follow the standardization prac-tices of Practice E1164.9. Procedure9.1 Measure the color of the reference specimen and calcu-late the CIELAB L*, a*, b*, C* and h values using the data forthe 10 observer and for illuminant D65.9.2 Measure the color of the test specimen which ha
23、s beensubjected to the colorfastness test and make the same colori-metric calculations as done for the reference specimen. Thenmake the calculations as described in Annex A1.10. Calculation or Interpretation of Results10.1 Acomplete description of the calculations, the symbolsand subscripts used in
24、them, is given in Annex A1 of thismethod.10.2 The results of the method derive GSCvalues that are inhalf-steps between five and a value of unity. These values forma scale of discrete steps. An alternative continuous scale inTable A1.1 is equivalent and may be used at the users option.The rounded val
25、ue GSCmay be used as an index in theleft-hand column to look-up the equivalent alternative continu-ous value in the right-hand column.11. Report11.1 Report the following information:11.1.1 A complete description of the test pair and thetreatment being evaluated by the destructive test;11.1.2 The cal
26、culated value of GSCcalculated in connectionwith this sample pair;11.1.3 The make, model, and serial number of the spectro-photometer used to make the spectral measurements, and thegeometry of the instrument, bidirectional or hemispherical. Ifthe geometry is hemispherical, state whether specular inc
27、ludedor specular excluded mode was employed;11.1.4 Astatement that D65 and the 10 Observer were usedto calculate the conventional colorimetric values, or, if acustom illuminant-observer was employed, which one, and ajustification for that deviation from the standard method.12. Precision and Bias12.1
28、 Precision6The repeatability 95 % confidence inter-val for two specimen pairs chosen from the same distributionfor a single set of observations has been determined to be 0.034GSCunits. In this test six specimen pairs were measured tentimes each on the same instrument, and the mean 95 %confidence int
29、erval for two pairs drawn from this population isreported. Thus, two test results made back to back on the samesample pair differ by more than this value are to be consideredsuspect.12.2 BiasNo information can be provided about the biasof the test method for measuring GSCbecause no materialhaving an
30、 accepted reference value is available.13. Keywords13.1 color difference; gray scale; instrumental color-difference6The reproducibility of this test method is being determined and is expected tobe available in April 2016.E3040 152ANNEX(Mandatory Information)A1. SYMBOLS AND CALCULATIONSA1.1 SymbolsA1
31、.1.1 The following subscripts are used in connection withthe symbols of A1.1.2.ab nominates that the scripted symbol is associated withthe CIELAB color-difference equation (see Practice D2244).F nominates that the scripted symbol is a special-case colordifference component for Gray Scale for change
32、in color, andthus differs in value from its CIELAB counterpart.K nominates that the scripted symbol has been chromacorrected, and thus differs in value from its CIELAB counter-part.M nominates the mean value of the scripted symbolbetween the test specimen and the reference specimen.R nominates that
33、the scripted symbol is associated with thereference specimen.T nominates that the scripted symbol is associated with thetest 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
34、 arealways in degrees, never radians. 2 radians are equal to 360degrees.x = a place-holder for a calculated exponent in the specialE equationsC = chroma differenceE = total color-differenceH = hue differenceL = lightness differenceG = a place-holder for the unrounded value of the colordifferenceA1.2
35、 CalculationsA1.2.1 The following instructions define the calculations:A1.2.1.1 Calculate L*, a*, b*, hab, and C*abof both thereference and the trial specimens in accordance with PracticeE308, or Practice D2244, whose instructions are identical toeach other.if Abs (hab,Thab,R) 180 thenhM=(hab,T+hab,
36、R)/2elseif Abs(hab,T+hab,R) 360 thenhM=(hab,T+hab,R)/2 + 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,TL*ab,RC*ab=C*ab,TC*ab,RCM= (C*ab,T+C*ab,R)D =(C*abCM ex)/100E*ab=(L*)2+(a*)2+(b*)21/2H*ab=(E*ab)2(L*)2(C*ab)21/2CK= C*
37、ab DHK= H*ab DCF= CK/1 + (10 CM/1000)2HF= HK/1 + (20 CM/1000)2EF=(L*)2+(CF)2(HF)21/2if EF 3.4 thenG=5EF/1.7elseif EF 16.15 thenG=5Log2(EF/0.85)elseG=1end ifend ifGSC=Int(2 G + 0.5)/2A1.2.1.2 Gray Scale Color Change TableSee Table A1.1.E3040 153A1.2.1.3 If the computer language used to invoke theseeq
38、uations does not contain a log2 function, the followingrelationship will be useful:log2X! 5log10X!log102!5lognX!logn2!(A1.1)where n refers to any base of a logarithm including that ofnatural logarithms.APPENDIX(Nonmandatory Information)X1. EXAMPLE CALCULATIONS FOR GRAY SCALE CHANGE IN COLORX1.1 If T
39、able X1.1 is used to check a computer program,discrepancies of 60.001 or occasionally 60.002, may arisedue to round-off, and do not call into question the programscorrectness.TABLE A1.1 Gray Scale for Color Change Alternate ScalesDiscrete Scale Continuous Scale554.5 45443.5 34332.5 23221.5 1211TABLE
40、 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 10.88
41、08 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 -1.96Cab16.08 15.05 1.41 2.02 2.71 3.04 4.46 2.56h 198.72 195.73 224.14 31.26 245.33 296.40 103.23 309.92HM197.22 307.70 270.86 26.57x 7.61 0.85 0.09
42、 12.62L*ab1.66 2.50 2.91 2.50C*ab-1.03 0.62 0.33 -1.90CM15.57 1.72 2.87 3.51D -0.0001 0.0045 0.0086 0.0000E*ab2.11 3.30 3.83 7.28H*ab0.81 2.06 2.47 6.57CK-1.03 0.61 0.32 -1.90HK0.81 2.06 2.46 6.57CF-1.00 0.61 0.32 -1.90HF0.74 2.06 2.46 6.54EF2.08 3.30 3.85 7.25G 3.78 3.06 2.83 1.91GSC4.00 3.00 3.00
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