ASTM D7195-2016 red 9462 Standard Guide for Setting Object Color Specifications《设置物体颜色规格的标准指南》.pdf

1、Designation: D7195 06 (Reapproved 2012)D7195 16Standard Guide forProtocol for Setting Object Color Specifications for aMaterial1This standard is issued under the fixed designation D7195; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisi

2、on, 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 guide leads the user through thea process for setting a color tolerance for a product or material

3、. It pointsestablishingcolor specifications, including the target color and allowable tolerances. It refers to the appropriate ASTM standards that affectmore thoroughly describe each step of the process. It includes the discussion points on which the two parties must agree andprovides caveats for va

4、rious options selected.process beginning with expectations, encompassing caveats within the process andfinally concluding with reporting.1.2 This guide does not suggest numerical values for tolerances. These values must be agreed upon by the two parties involved.1.3 This standard does not purport to

5、 address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D523 Test M

6、ethod for Specular GlossD1729 Practice for Visual Appraisal of Colors and Color Differences of Diffusely-Illuminated Opaque MaterialsD2244 Practice for Calculation of Color Tolerances and Color Differences from Instrumentally Measured Color CoordinatesD3134 Practice for Establishing Color and Gloss

7、TolerancesD3964 Practice for Selection of Coating Specimens for Appearance MeasurementsD4086 Practice for Visual Evaluation of MetamerismD4449 Test Method for Visual Evaluation of Gloss Differences Between Surfaces of Similar AppearanceD5531 Guide for Preparation, Maintenance, and Distribution of Ph

8、ysical Product Standards for Color and GeometricAppearance of CoatingsE179 Guide for Selection of Geometric Conditions for Measurement of Reflection and Transmission Properties of MaterialsE253 Terminology Relating to Sensory Evaluation of Materials and ProductsE284 Terminology of AppearanceE308 Pra

9、ctice for Computing the Colors of Objects by Using the CIE SystemE805 Practice for Identification of Instrumental Methods of Color or Color-Difference Measurement of MaterialsE1164 Practice for Obtaining Spectrometric Data for Object-Color EvaluationE1345 Practice for Reducing the Effect of Variabil

10、ity of Color Measurement by Use of Multiple MeasurementsE1347 Test Method for Color and Color-Difference Measurement by Tristimulus ColorimetryE1499 Guide for Selection, Evaluation, and Training of ObserversE1708 Practice for Electronic Interchange of Color and Appearance DataE1808 Guide for Designi

11、ng and Conducting Visual ExperimentsE2214 Practice for Specifying and Verifying the Performance of Color-Measuring InstrumentsE2867 Practice for Estimating Uncertainty of Test Results Derived from Spectrophotometry1 This guide is under the jurisdiction ofASTM Committee E12 on Color andAppearance and

12、 is the direct responsibility of Subcommittee E12.04 on Color andAppearanceAnalysis.Current edition approved June 1, 2012July 1, 2016. Published July 2012August 2016. Originally approved in 2006. Last previous edition approved in 20062012 as D7195 06. 06 (2012). DOI: 10.1520/D7195-06R12.10.1520/D719

13、5-16.2 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 on the ASTM website.This document is not an ASTM standard and is intended on

14、ly to provide the user of an ASTM standard an indication of what changes have been made to the previous 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 vers

15、ionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States12.2 CIE PublicationsPublications:CIE 15:2004Publication 015 Colorimetry, 3Colorimetryrd edition 33. Term

16、inology3.1 DefinitionsFor definitions of terms related to this guide see Terminology E253 and Terminology E284.4. Summary of Guide4.1 This guide describes the process for establishing a color specificationspecifications for a material, including the decision asto whether this specification will be b

17、ased on visual or instrumental methods.4.2 General considerations of appearance, evaluation of observers, and measurement techniques are included.4.3 It begins the process of setting a tolerance by first selecting a standard or target color for the material, including theproduction, measurement, and

18、 storage of that target.4.4 It next identifies methods to establish acceptable color tolerances.4.5 Finally, it discusses reporting techniques.5. Significance and Use5.1 The rejection of materials due to color is a common and expensive occurrence, and it is useful for a customer and producerto set a

19、 color specificationspecifications with an associated tolerance before the transaction. This guide discusses the concept anddetails the ASTM standards to be used in the process.6. Introduction6.1 A common reason stated for rejection of goods or materials is that the product color does not meet expec

20、tations. The bestway to avoid the problem of returned goods or materials because of color is to establish a color specificationspecifications withan associated tolerance.tolerances. Then the producer can be confident that if they supply material that falls within the colorspecification, the customer

21、 will accept the color of the product.6.2 To supply colorproduct within specification consistently requires production that is inunder statistical process control, anda program of color measurement and evaluation6.3 This guide will lead the user through the decision-making process and point to the a

22、ppropriate ASTM standards that arepertinent to each step. It will include the discussion points on which the two parties must agree and will provide caveats for variousoptions selected.7. General Discussions7.1 In setting up the specification, one must first decide whether there will be a visual or

23、instrumental evaluation of the color.Observers have different color perception skills. A highly trained colorist can see very minute color differences whereas the morecasual observer or color-anomalous observer would not normally detect very small differences. Additionally, the visual abilitiesor pe

24、rception levels of observers, may vary between persons and over time within an individual. Thus if the color of the materialwill be evaluated visually, we must ensure consistent conditions for the evaluation. Guide E1499 provides more detailedinformation.detailed information about the selection of o

25、bservers. Guide E1808 provides guidance on how to conduct criticalvisual observations.7.2 Numerous advances have occurred in both the accuracy and repeatability of color measurement instruments. However, theremay still be considerable differences between instruments of different make, type, and geom

26、etry. Advances have also occurred inthe equations and software programs for evaluating color and color quality control. It is not uncommon for the specification to beset numerically and evaluated by instrumental measurement, but then the question “what should my tolerance be?” must beresolved.7.3 A

27、number of color difference calculations are widely used throughout industry. See Practice D2244 for more details on thecolor difference and color tolerance equations. Which color-difference metric will be used should be agreed upon by the two partiesinvolved. For years, color tolerances were set up

28、as boxes. However, it is now possible and desirable to use ellipticaltolerancing.rectangular tolerancing. In some industries the phrase “box tolerancing” is the accepted terminology. However,elliptical tolerancing is preferred.7.4 In most cases, the limits of acceptability will be greater than a jus

29、t perceptible difference, but in some cases, the tolerancemay be less than a perceptible difference. If it is less than a perceptible difference, then instrumental methods will have to be used.Both the producer and the customer should refer to Practice E2214.3 Available from U.S. National Committee

30、of the CIE (International Commission on Illumination), C/o Thomas M. Lemons, TLA-Lighting Consultants, Inc., 7 Pond St.,Salem, MA 01970, http:/www.cie-usnc.org.http:/.D7195 1627.5 While the goal is to have an agreed color specification with an acceptable tolerance for both the producer and the custo

31、mer,each party must carefully consider their position. The producer must know that they are able to control the color in production tothe level specified without excessive waste and undue loss. The customer must be assured that the tolerance is such that the colorof the goods will be functionally ac

32、ceptable.7.6 Color is one aspect of the appearance of a material. Other appearance parameters include, but are not limited to, gloss, haze,and texture. In order to compare the color of a test material to a target material, either visually or instrumentally, the other allaspects of appearance should

33、be the same, or as similar as possible. Test Method D4449 covers the visual evaluation of gloss, glossdifference, while Test Method D523 covers instrumental gloss measurement.7.7 Since it is not always possible to have all appearance parameters the same or even if they are the same, it is important

34、touse established viewing conditions. These include the illumination, the positioning of the standard and specimen, and the receptorsystem, whether human or instrumental. If one is trying to have instrumental readings that correlate with the visual appearance ofa material, one needs to establish con

35、sistency between the visual situation and the instrumental set up. Guide E179 discusses theterminology and instrumentation for evaluating appearance characteristics. Some of the considerations when choosing thegeometry of evaluation are:7.7.1 What are your internal needs such as formulation, quality

36、 control, auditing, trouble shooting?7.7.2 What are your customerscustomers specifications and needs?7.7.3 Do you want the numbers to match visual evaluation?7.7.4 If the gloss or surface texture of the standard and specimen are different, do you want specimensspecimens gloss or grainlevels to produ

37、ce the same colorimetric values when measured?7.7.5 Do you want to deal with a small or large process window?7.8 It is important to have the producer and the customer agree on the target color and the criterioncriteria for acceptance. Formany users the final criterion is visual acceptance, that is,

38、visual appearancecolor is the final deciding factor. However, some usershave demonstrated that more consistent product quality is obtained instrumentally, avoiding the “final visual inspection.” Once thecolor is agreed upon, then one should decide whether to use visual or objective standards and tol

39、erances.7.8.1 Some of the advantages of using a digital standard are:7.8.1.1 Both supplier and customer have the same absolute numbers to judge against, the same starting point,7.8.1.2 Reduced costs of making and maintaining master standards,7.8.1.3 Easy to communicate an absolute number through e-m

40、ail or voicemail, electronically, and7.8.1.4 Faster; and fewer subjective calls.7.8.2 Some of the disadvantages of using a digital standard are:7.8.2.1 For best consistency, both supplier and customer must have the same instrument,7.8.2.2 There is no physical standard available to use for a visual c

41、omparison,7.8.2.3 It is especially risky The risk increases if different materials, technologies or different suppliers are used, and7.8.2.4 There is less opportunity to ship acceptable-color product that matches but have numbers on the borderline or slightlyfail.greater than the numerical tolerance

42、.7.9 Maintaining master and working physical standards is discussed in detail in Guide D5531. However, some important aspectsare repeated here.7.9.1 Store masters master standards in a suitable protective material, under appropriate temperature and humidity conditionsfor the material to keep it in o

43、ptimal condition (in the dark, away from heat sources, chemical fumes, direct sun-rays, etc.) andonly remove when necessary to verify new working standards.7.9.2 Maintain multiple working standards, with only one in circulation at a given time.7.9.3 Handle master standards with lint-free gloves.7.9.

44、4 Record dates on all master and working standards when they are approved and by whom.7.9.5 Frequently inspect working standards for scratches, changes in gloss or color.7.9.6 Match to a signed-offan approved (working master) part and routinely check the color difference between the master andthe wo

45、rking master to ensure that neither has the working standard has not changed.NOTE 1Once the working master has been established, it is desirable to use this rather than going back to the master because reference to the mastercan open the door for instrumental measurements and visual evaluations to b

46、e different.7.10 All measured values have an uncertainty associated with the measurement. In order to Estimate the uncertainty of testresults using Practice E2867. To reduce the confidence limits associated with color or color-difference measurements of coloredmaterials, statistical analysis of the

47、results of multiple measurements on a single specimen or the measurement of multiplespecimens can be used. This procedure is described in Practice E1345.7.11 It is best if the standard and the trial material can be measured at the same time, on the same equipment by the sameoperator. This Single ope

48、rator precision is the best way to eliminateestimate production, test and raw material effects.D7195 1638. Procedure for Setting a Tolerance8.1 Section 8 gives the steps for setting a tolerance. Table 1 summarized theASTM Standards referenced for each of these steps.8.2 The first step is to establis

49、h a physical (master) standard that represents the required color and to assure that all the (working)standards used in the control program match that color within a very small tolerance. See Practice D3964.Additionally, a programshould be established to monitor the color quality of those working standards. See Guide D5531. Sample preparation is a veryimportant issue. The surface characteristics and texture are important considerations and should be consistent.NOTE 2For coatings one might spray (using a specific procedure) or draw down the specimens. Fo