Color Analysis – CIE94 (ASTM E with ASTM D). Color Analysis – Hunter (ASTM E & ASTM D). Scope: Hunter Lab and XYZ are standard . This standard is issued under the fixed designation D ; the number 1 This practice is under the jurisdiction of ASTM Committee E12 on Color and. ASTM D Standard Practice for Calculation of Color Tolerances and Color Differences from Instrumentally Measured Color Coordinates.
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Today, while instruments intended for use in color measurements share many common components, UV-VIS analytical spectrophotometers are designed to optimize their use in chemometric quantitative analysis, which requires very precise spectral position and very narrow bandpass and moderate baseline stability.
Where it is suspected that the specimens may be metameric, that is, possess different spectral curves though visually alike in color, Practice D should be used to verify instrumental results.
Color Analysis – CIE94 (ASTM E1347 with ASTM D2244)
Typically a 50 mm 2″ or mm 4″ disk Data: Color-difference units are computed, from these color-scale values, and approximate the perceived color differences between the reference and the test specimen. Validating the specifications, value and safety of your raw materials, products and assets. Precision and Bias Examples of Ka and Kb are tabulated in Table X1. Color analysis can be used to match adjacent parts molded from different materials, or to evaluate color change due to outdoor exposure.
Certification Formally confirming that your products and services meet all trusted external and internal standards. Astj CIELAB color-difference equation is also not recommended in this practice for use in describing small and moderate color differences differences with magnitude less than 5.
See Practice E Need help or have a question?
Table 2 gives the mean color differences and their standard deviations for the groups of instruments considered While not obvious from this listing, all displayed angles are assumed to be given in degrees, including Du and thus must generally be converted into radians for trigonometric analysis on digital computers. Standards can be obtained from appropriate standards authorities.
Assurance Enabling you to identify and mitigate the intrinsic risk in your operations, supply chains and business processes. ASTM International takes no position respecting r2244 validity of any patent rights asserted in connection with any item mentioned in this standard.
Both are appropriate for and widely used in industrial and commercial applications including, but not limited to, automobiles, coatings, cosmetics, inks, packaging, paints, plastics, printing, security, and textiles. The three tolerance equations given here have been tested extensively against such data for textiles and plastics and have been shown to agree with the visual evaluations to within the experimental uncertainty of the visual judgments.
After specifying the illuminant, observer angle, and the reference color, the test sample is inserted into the specimen holder and the spectrophotometer takes the reading.
Individual reprints asmt or multiple copies of this standard may be obtained by contacting ASTM at the above address or at phonefaxor service astm. While the CIELAB equation has not completely replaced the use of Hunter LH, aH, bH, this older scale is no longer recommended for other than legacy users, and is therefore included in an Appendix for historical purposes. Summary of Practice 4. This standard has been approved for use by agencies of the Department of Defense.
The four color space terms are computed as follows: Consequently, color differences are seldom if ever computed asstm from differences in x, y, and Y. Historical Version s – view previous versions of standard. However, for control of color in production, it may be necessary to know not only the magnitude of the departure from standard but also the direction of this departure.
To avoid confusion, satm differences among specimens or the associated tolerances should be compared only when they are obtained for the same color-scale system.
A color difference equation quanti? The parameters kL, kC, kH, are the parametric factors that can be used to compensate for texture and v2244 specimen presentation d224 while kV is used to adjust the size of the tolerance volume for industrial bias. For textiles the following equivalence relations holds: The are computed using the following equations: As revised init included four color spaces in which color-scale values could be measured by instruments, many of which were obsolete, and the color differences calculated by ten equations for different color scales.
Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard.
It is possible to include information on the direction of a small color difference by listing the three instrumentally determined components of the r2244 difference. The most common values are 2: Hunter Lab and XYZ are standard three dimensional color spaces that allows a precise definition of the color of a test sample.
In a typical recent survey Report No. This is convenient for certain textile sorting applications and for graphical quality control charting. Testing Evaluating how your products and services meet and exceed asym, safety, sustainability and performance standards. Evaluating how your products and services meet and exceed quality, safety, sustainability and performance standards.
There is no simple factor that can be used to convert accurately color differences or color tolerances in one system to difference or tolerance units in another system for all colors of specimens.
Its weighting functions are much simpler than those of the Awtm equation. Good correlation with the visual judgments may not be obtained when the calculations are made with other illuminants. A number in parentheses indicates the year of last reapproval.
Originally approved in The three tolerance equations given here have been tested extensively against such data for textiles and plastics and have been shown to agree with the visual evaluations to within the experimental uncertainty of the visual judgments. Thus computed color differences aastm based only on the Euclidean distance in the DIN99 space. Where it is suspected that the specimens may be metameric, that is, possess different spectral curves though visually alike in color, Practice D should be used to verify instrumental results.
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ASTM D ColorTolerance_百度文库
The four more recently de? ASTM D von Nor is it possible or reasonable to plot groups of colors in terms of the modi? CIE94 tolerances are computed as follows: In the process, the researchers came to the conclusion that neither formula adtm truly optimum.