1、Designation: E3040 16Standard 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 last revi
2、sion. 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 no
3、n-self-luminous materials by comparison tothis scale. This practice 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 that
4、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. It is t
5、heresponsibility 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 Instrume
6、ntally 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 Stand
7、ards: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 Instrumental det
8、ermination 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 lightne
9、ss, 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 specime
10、n.4. Summary of Test Method4.1 The color of a specimen that has been submitted to a testwhose severity is evaluated by change in color, and an identicaluntreated specimen, are measured spectrophotometrically andboth of their colors evaluated by conventional means. Theconventional color difference at
11、tributes are converted to a GrayScale for Color Change by a series of calculations.4.2 This practice is similar to the following three interna-tional methods: AATCC Evaluation Procedure 7, ISO 105-A05, and JIS L 0809.1This practice is under the jurisdiction of ASTM Committee E12 on Color andAppearan
12、ce and is the direct responsibility of Subcommittee E12.04 on Color andAppearance Analysis.Current edition approved July 1, 2016. Published July 2016. Originally approvedin 2015. Last previous edition approved in 2015 as E3040 15. DOI: 10.1520/E3040-16.2For referenced ASTM standards, visit the ASTM
13、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.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036,
14、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 from Japanese Standards Association (JSA), Mita MT Bldg., 3-13-12Mita, Minato-ku, Tokyo 108-0073, Japan, http:/www.j
15、sa.or.jp.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15. Significance and Use5.1 The gray scale grade GSCis useful to evaluate the colordifference of any pair of colors that have been subjected to atest whose severity of result is
16、nominated by color difference ofthe treated member to the untreated member. This includes, butis not limited 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 ofobtaining gray scale gr
17、ades is that under the visual methodsubstantial 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. App
18、aratus6.1 Spectrophotometer, having one 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 f
19、or choosing one over theother, hemispherical 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 used in this practice are nearlyalways a pair of identical specime
20、ns where one member of thepair has been subjected to a test whose severity of result maybe quantified by a change in color.7.2 The practice 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
21、 tothe nearest half-unit on 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 a
22、ccordance with themanufacturers 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
23、 the test specimen which has 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 sym
24、bolsand subscripts used in 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 u
25、sers option.The rounded value 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 dest
26、ructive test;11.1.2 The calculated 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,
27、 state whether specular includedor 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
28、.12. Precision and Bias12.1 PrecisionThe practice does not in itself contribute touncertainty 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 biasof the test method for measuring GSCbe
29、cause no materialhaving an accepted reference value is available.13. Keywords13.1 color difference; gray scale; instrumental color-differenceE3040 162ANNEX(Mandatory Information)A1. SYMBOLS AND CALCULATIONSA1.1 SymbolsA1.1.1 The following subscripts are used in connection withthe symbols of A1.1.2.a
30、b 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 in color, andthus differs in value from its CIELAB counterpart.K nominates that
31、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 the scripted symbol is associated with thereference specimen.T nominates that th
32、e 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 arealways in degrees, never radians. 2 radians are equal to 360degrees.x = a pl
33、ace-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 CalculationsA1.2.1 The following instructions define the calculations:A1.2.1.1
34、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,R)/2elseif Abs(hab,T+hab,R) 360 thenhM=(hab,T+hab,R)/2 + 180elsehM=(hab,T+hab,R)
35、/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*ab DHK= H*ab DCF= CK/1 + (10 CM/1000)2HF= HK/1 + (20 CM/1000)2EF=(L*)2+(CF)2(HF)
36、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 163A1.2.1.3 If the computer language used to invoke theseequations does not contain a log2 function, the followingrelationship will be usef
37、ul: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 Table X1.1 is used to check a computer program,discrepancies of 60.001 or occasio
38、nally 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 X1.1 Example Calculations for Gray Scale for Change in ColorParam. STD-1 BAT-1
39、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 10.8808 15.0329L* 50.47 52.13 60.41 62.91 72.30 75.21 40.61 43.11a* -15.23 -14.49 1.0
40、1 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 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
41、.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 2.00E3040 164ASTM International takes no position respecting the validity of any
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