ASTM D2244 PDF
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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Color Analysis – CIE94 (ASTM E1347 with ASTM D2244)
The X-Rite i7 Colorimeter is highly automated. That implies that the equations themselves misclassify a color difference with a frequency no greater than that of the most experienced visual color matcher.
Inter-changing the reference and test specimens does not change either the perceived or predicted color differences. 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. The next section, uses data from a commercial collaborative testing program astj illustrate precision for one material.
They are, therefore, included in Appendix X1 for historical purposes and use. The CIELAB metric, with its associated color-difference equation, has found d244 acceptance in the coatings, plastics, textiles and related industries.
Digital colorimetry allows more tolerance on the spectral scale and spectral bandwidth but demand much more stability in the radiometric scale. Use of a tolerance equation for other d22444 daylight conditions will require visual confirmation of the level of metamerism in accordance with Practice D Enabling you to identify and mitigate the intrinsic risk in your operations, supply chains and business processes.
Formally confirming that your products and services meet all trusted external and internal standards. Record the location where these measurements were made on the specimen. Each subsequent color scale based on CIE values xstm 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.
Thus computed color differences are based only on the Euclidean distance in the DIN99 space. 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.
To avoid confusion, color differences among specimens or the associated astmm should be compared only when they are obtained for the same color-scale system. All the k values default to 1 in d2244 absence of speci? 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.
See Practice E Validating the specifications, value and awtm of your raw materials, products and assets.
Individual reprints single or multiple copies of this standard may be obtained by contacting ASTM at the above address or at phonefaxor service astm. The revision published in omitted these sections, and limited the color spaces and color-difference equations considered, to the three most widely used in the paint and related coatings industry.
ASTM D ColorTolerance_百度文库
ASTM D von 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. The three tolerance equations given here have been aetm 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.
Send us a request Wilton UK: 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.
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. Under these conditions, Xn, Yn, Zn are the tristimulus values of d244 standard illuminant with Yn equal to Additionally, d22444 colorimetric spectrometer may also be able to report the underlying spectral data from which the colorimetric data were derived.
Standards can be obtained from awtm standards authorities. The most common values are 2: Color-difference units are computed, from these color-scale sstm, and approximate the perceived color differences between the reference and the test specimen.
The three tolerance equations given here have asgm tested extensively against such data for textiles and plastics and have been shown to agree with the visual evaluations to within d22444 experimental uncertainty of the visual judgments. Each material and condition of use may require speci? For specimens that are matte, randomly rough, or mildly textured, values intermediate between 1: 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.
This standard is subject to revision at any time by the responsible technical committee and asmt be reviewed every?
ASTM D – COLOR DETERMINATION
Auditing Consulting Sourcing Training. Assurance Testing D22444 Certification. Specular component included for integrating-sphere measurements. 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.
Assurance Enabling you to identify and mitigate the intrinsic risk in your operations, supply chains and business processes.
Originally approved in This is convenient for certain textile sorting applications and for graphical quality control charting. Global Reach Intertek is the industry leader with over 42, people in 1, locations in over countries. Send us a request Need help or have a question?
Inspection Validating the specifications, value and safety of your raw materials, products and assets. This standard has been approved for use by agencies of the Department of Defense. 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 d2244.