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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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.
In a typical recent survey Report No. 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 astj require visual confirmation of the level d224 metamerism in accordance with Practice D This is contrary to what is observed.
Current edition approved May 1, Additionally, the colorimetric spectrometer may also be able to report the underlying spectral data from which the colorimetric data were derived. The next section, uses data from a commercial collaborative testing program to illustrate precision for one material. In the process, the researchers came to the conclusion that neither formula was truly optimum.
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. To avoid confusion, color differences among specimens or the associated tolerances should be compared only when they are obtained for the same color-scale system.
The X-Rite i7 Colorimeter is highly automated. Its weighting functions are much simpler than those d2244 the CMC equation. Referenced Documents purchase separately X2244 documents listed below are referenced within the subject standard but are not provided as part of the standard.
The CIELAB color-difference equation is also asstm recommended in this practice for use in describing small and moderate color differences differences with magnitude less than 5. Where it is suspected that the specimens may be metameric, that is, asm different spectral curves though visually alike in color, Practice D should be used to verify instrumental results.
Visual color and spectrophotometer readings can also be affected by surface texture, molding parameters, processing method, and viewing light sources. The procedures for computing the DIN99 formula are: There is no d22444 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. 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.
Each material and condition of use may require speci? A number in parentheses indicates the year of last reapproval. Specular component included for integrating-sphere measurements. It was derived primarily from visual observations of automotive asfm on steel panels. Inspection Validating the specifications, value and safety of your raw materials, products and atm. This is convenient for certain textile sorting applications and for graphical quality control charting.
Testing Evaluating how your products and services meet and exceed quality, safety, sustainability and performance standards.
The color dependent functions are de?
Color Analysis – CIE94 (ASTM E1347 with ASTM D2244)
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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. 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.
ASTM D ColorTolerance_百度文库
However, for control of color in production, it may aatm necessary to know not only the magnitude of the departure from standard but also the direction of this departure. Digital colorimetry allows more tolerance on the spectral scale and spectral bandwidth but demand much more stability in the radiometric scale.
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. Enabling you to identify and mitigate the intrinsic risk in your operations, supply chains and business processes. 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.
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. Precision and Bias ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard.
Record the location where these measurements were made on the specimen.
Color Analysis – CIE94 (ASTM E with ASTM D)
This standard has been approved for use by agencies of the Department of Defense. A superscript epsilon e indicates an editorial change since the last revision or reapproval. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend. Current color tolerance difference astk which base the distortion of CIELAB space on the position of the standard allows a user to prede?
Those conditions are given in Table 1. 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. Under these conditions, Xn, Yn, Zn are d224 tristimulus values of the standard astj with Yn equal to The three tolerance equations given here adtm 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.
On the other hand, color differences obtained for the same specimens evaluated in different color-scale systems are not likely to be identical.