ASTM D2244 PDF

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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-difference units are computed, from these color-scale values, and approximate the perceived color differences between the reference and the test specimen. The are computed using the following equations: Assurance Enabling you to identify and mitigate the intrinsic risk in your operations, supply chains and business processes.

ASTM D2244

Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend. 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 asmt specimens.

Specular component included for integrating-sphere measurements. Through our network of over 43, people in 1, laboratories and offices in countries, Intertek provides quality and safety solutions to a wide range of industries around the world.

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. It was derived primarily from visual observations of automotive paints on steel panels. In the process, the researchers came to the conclusion that neither formula was truly optimum. Formally confirming that your products and services meet all trusted external and internal 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.

Good correlation with the visual judgments may not be obtained when the calculations are made with other illuminants. Current edition approved May 1, 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.

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The procedures for computing the DIN99 formula are: A previous revision added two new color tolerance equations and put two of the color difference equations from the version in an informative appendix for historical purposes.

The four color space terms are computed as follows: Validating the specifications, value and safety of your raw materials, products and assets. 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.

Color Analysis – CIE94 (ASTM E1347 with ASTM D2244)

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. 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. The parameters kL, kC, kH, are the parametric factors that can be used to compensate for texture and other specimen presentation effects while kV is used to adjust the size of the tolerance volume for industrial bias.

The four more recently de?

Send us a request Need help or have a question? There should not be a need to break the equation down into perceptual components—the CIELAB components of the model do that already. The color dependent functions are de?

Precision and Bias Evaluating how your products and services meet and exceed quality, safety, sustainability and performance standards. Digital colorimetry allows more tolerance on the spectral scale and spectral bandwidth but demand much more stability in the radiometric scale. Record the location where these measurements were made on the specimen.

Color Analysis – CIE94 (ASTM E with ASTM D)

Standards can be obtained from appropriate standards authorities. Assurance Testing Inspection Certification. Originally approved in 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. In a typical recent survey Report No.

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There is no simple factor that asgm be used to convert accurately color differences or d244 tolerances in one system to difference or tolerance units in another system for all colors of specimens. 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.

Consequently, color differences are seldom if ever computed directly from differences in x, y, and Y. The next section, uses data from a commercial collaborative testing program to illustrate precision for one material.

Approved May 1, 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.

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. Use of a tolerance equation for other than daylight conditions will require visual confirmation of the level of metamerism in accordance with Practice D Each material and condition of use may require speci?

ASTM Asgm von Link to Active This link will always route to the current Active version e2244 the standard.

ASTM D – COLOR DETERMINATION

Each subsequent color scale based on CIE 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. Each asttm 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.

This d2244 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.