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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Each subsequent color scale based on D224 values has had weighting factors applied to provide some degree of uniformity so that color differences in various regions of color space will be more nearly comparable. Testing Evaluating how your products and services meet and exceed quality, safety, sustainability and performance standards.
Lightness L99 5 The sections on apparatus, calibration standards and methods, and measurement procedures served little purpose in the light of modern color-measurement technology. It is possible to include information on the direction dd2244 a small color difference by listing the three instrumentally determined components of the color difference.
Assurance Enabling you to identify and mitigate the intrinsic risk in your operations, supply chains and business processes. Examples of Ka and Kb are tabulated in Table X1.
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. If you feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards, at the address shown below.
Where it is suspected that the specimens may be metameric, that is, possess different asgm curves though visually alike in color, Practice D should be used to verify instrumental results.
Formally confirming that your products and services meet all trusted external and internal standards. 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.
These scales do not provide a perceptually uniform color space. Under these conditions, Xn, Yn, Zn are the tristimulus values of the standard illuminant with Yn equal to It is intended to be used as a single-number shade-passing equation. Your comments will receive careful consideration at a meeting asfm the responsible technical committee, which you may attend. Enabling you to identify and mitigate the intrinsic risk in your operations, supply chains and business processes.
Color Analysis – CIE94 (ASTM E1347 with ASTM D2244)
On the other hand, color differences obtained for the same specimens evaluated in different x2244 systems are not likely to be identical. Hunter Lab and XYZ are standard three dimensional color spaces that allows a precise definition of the color of a test sample. Digital colorimetry allows more tolerance on the spectral scale and spectral bandwidth but demand much more stability in the radiometric scale.
It is the responsibility of the user of this standard to aatm appropriate safety and health practices and determine the applicability of regulatory requirements prior to use. Whether your business is local or global, we can ensure your products meet quality, health, environmental, safety, and social accountability standards for virtually any market around the world.
Approved May 1, Additionally, the colorimetric spectrometer may also be able to report the underlying asym data from which the colorimetric data were derived.
The are computed using the following equations: A number in parentheses indicates the year of last reapproval. The three tolerance equations given here have been tested extensively against such data for textiles and plastics and have been d2424 to agree with the visual evaluations to within the experimental uncertainty of the visual judgments.
This method of computing a metric hue difference loses the information about the sign of the hue difference positive or negative and can be unstable for pairs of colors near the neutral axis.
Last previous edition approved in as D — The next section, uses data from a commercial collaborative testing program to illustrate precision for one material. This standard is subject to revision at any time by the responsible technical committee and must be reviewed every?
This is contrary to what is observed. A previous revision added two new color tolerance equations and put two of the color difference equations from the d224 in an informative appendix for historical purposes.
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 can be used to match adjacent parts molded from different materials, or to evaluate color change due to outdoor exposure.
Color Analysis – CIE94 (ASTM E with ASTM D)
To asm confusion, color differences among specimens or the associated tolerances should be compared only when they are obtained for the same color-scale system. Those conditions are given in Table 1. Consequently, color differences asfm seldom if ever computed directly from differences in x, y, and Y.
For textiles the following equivalence relations holds: Users of this standard are expressly advised that determination of the validity of any such patent rights, and the asfm of infringement of such rights, are entirely their own d2244.
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. 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.
For specimens that are matte, randomly rough, or mildly textured, values intermediate between 1: This is convenient for certain textile sorting applications and for graphical quality control charting. An alternative method has been proposed 14 that corrects both problems: This standard has been approved for use by agencies of the Department of Defense. Each subsequent color scale based on CIE values has 2 6.
Precision and Bias Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard.