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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Testing Evaluating how your products and services meet and exceed quality, safety, sustainability and performance standards. By using the position of the arithmetic average color between the two specimens to compute the local distortions to CIELAB color space, the roles of the two specimens may be switched without changing the magnitude of the computed colordifference, in full agreement with the visual assessments.
That implies that the equations themselves misclassify a color difference with a frequency no greater than that of the most experienced visual color matcher. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, are entirely their own responsibility.
Formally confirming that your products and services meet all trusted external and internal standards. Last previous edition approved in as D — ASTM D von It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory requirements prior to use.
It is possible to include information on the direction of a small color difference by listing the three instrumentally determined components of the color difference. Lightness L99 5 In the process, the researchers came to the conclusion that neither formula was truly optimum. Individual reprints single or multiple copies of this standard may be obtained by contacting ASTM at the above address or at phonefaxor service astm.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every?
ASTM D ColorTolerance_百度文库
On the other hand, color differences obtained for the same specimens evaluated in different color-scale systems are not likely to be identical. An alternative method has been proposed 14 that corrects both problems: They are, therefore, included in Appendix X1 for historical purposes and use.
The CIELAB color-difference equation is also not recommended in this practice for use in describing small and moderate color differences differences with atsm less than 5. Visually, there is no change in the magnitude of the difference between the specimens simply by switching roles. Usually, the white object-color stimulus is given by the spectral radiant power of one of the CIE standard illuminants, for example, C, D65 or another phase of daylight, re?
Link to Active This link will asm route to the current Active version of the standard. Consequently, color differences are seldom if ever computed directly from differences in x, y, and Y. Each subsequent color scale based on CIE values has 2 6.
The CMC components and single number tolerances are computed as follows: See Practice E The four more recently de? Color-difference units are computed, from these d22444 values, and approximate the perceived color differences between the reference and the test specimen.
Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard.
Visual color and spectrophotometer readings can also be affected by surface texture, molding parameters, processing method, and viewing light sources. 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. This standard has been approved for use by agencies of the Department of Defense.
ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. The are computed using the following equations: That implies that the equations themselves misclassify a color difference with a frequency no greater than that of the most experienced visual color matcher. Record the location where these measurements were made on the specimen.
Each material and condition of use may require specific color tolerances because other appearance factors, for example, specimen proximity, gloss, and texturemay affect the correlation between the magnitude of a measured color difference and its commercial acceptability. Those conditions are given in Table 1. Because of the many trigonometric functions and power functions involved in computing the color asttm parameters, all computations should be carried out in IEEE?
It is possible to include information on the direction of a small color difference by listing the three instrumentally determined components of the color difference. Inter-changing the reference and test specimens does not change either the perceived or predicted color differences. Colorimetric spectrometers are designed to optimize their use as digital simulations of d244 visual colorimeter or as the source of spectral and colorimetric information for computer-assisted color matching systems.
Additionally, the colorimetric spectrometer atsm also be able to report the underlying spectral data from which the colorimetric data were derived.
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Color Analysis – CIE94 (ASTM E1347 with ASTM D2244)
Thus computed color differences are based only on the Euclidean distance in the DIN99 space. It is intended to be used as a single-number shade-passing equation.
The CIELAB metric, with its associated color-difference equation, has found wide d22444 in the coatings, plastics, textiles and related industries. 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.
The tristimulus values Xn, Yn, Zn de?
ASTM D – COLOR DETERMINATION
Approved May 1, In a typical recent survey Report No. Each material and d22444 of use may require speci? After specifying the illuminant, observer angle, and the reference color, the test sample is inserted into the specimen holder and the spectrophotometer takes the ashm.
CIE94 tolerances are computed as follows: 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.
Specular component included for integrating-sphere measurements.
All the k values default to 1 in the absence of speci? The color dependent functions are de? The sections on apparatus, calibration standards and methods, and measurement procedures served little purpose in the light of modern color-measurement technology.