ASTM D Standard Test Method for Specular Gloss. ASTM D Standard test method for specular gloss ASTM International offers global access to standards development for over participating countries. 21 มี.ค. แจก ASTM D, Standard Test Method for Specular Gloss. Link down load: ire 6he8e9czn. The customer isn’t.
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Copyright ASTM Standard Test Method for Specular Gloss1 This standard is issued awtm the xed designation D ; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.
A superscript epsilon e indicates an editorial change since the last revision or reapproval. This f523-89 has been approved for use by agencies of the Department of Defense. The values given in parentheses are for information only. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
Current edition approved March 31, Originally published as D — 39 T. Last previous edition D — 85e1.
Gloss Meter Introduction | Industry Standards ASTM
Summary of Test Method 4. The geometry of angles and apertures is chosen so that these procedures may be used as follows: Signicance and Use 5. The directions associated with mirror or specular reection normally have the highest reectances. Measurements by this test method correlate with visual observations of surface shininess made at roughly asm corresponding angles. Since specular reectance depends also on the surface refractive astn of the specimen, the measured gloss ratings change as the surface refractive index changes.
In obtaining the visual gloss ratings, however, it is customary to compare the specular reectances of two specimens having similar surface refractive indices. Astj the instrumental ratings are affected more than d52-89 visual ratings by changes in surface refractive index, non-agreement between visual and instrumental gloss ratings can occur when high gloss specimen surfaces differing in refractive index are compared.
Test Method E includes techniques for the measurement of both distinctness-of-image gloss and reection haze. Test Method D provides an alternative procedure for measuring reection haze. However, in many applications the gloss scales of this test method have provided discriminations between coated specimens that have agreed well with visual discriminations of gloss The receptor shall be a photosensitive device responding to visible radiation.
แจก ASTM D523-89, Standard Test Method for Specular Gloss.
The length of the illuminated area of the specimen shall be not more than one third of the distance from the center of this area to the receptor eld stop. The dimensions and tolerance of the source and receptor shall be as indicated in Table 1. The angular dimensions of the receptor eld stop are measured from the receptor lens in a collimated-beam-type instrument, as illustrated in Fig. The tolerances are chosen so that errors in the source and receptor apertures do not produce an error of more than one gloss unit at any point on the scale 5.
NOTE 1—The parallel-beam glossmeters possess the better uniformity of principle-ray angle of reection, but the converging-beam glossmeters possess the better uniformity in extent of angular divergence accepted for measurement.
NOTE 2—Polarization—An evaluation of the impact of polarization on gloss measurement has been reported The magnitude of the polarization error depends on the difference between the refractive indices of specimen and standard, the angle of incidence, and the degree of polarization. Because the specimen and standard are generally quite similar optically, measured gloss values are little affected by polarization. The axis of the receptor shall be at the mirror reection of the axis of the incident beam.
The axis of the incident beam and the axis of the receptor shall be within 0. With a at piece of polished black glass or other front-surface mirror in the specimen position, an image of the source shall be formed 6.
Since specular reection is, in general, spectrally nonselective, spectral corrections need to be applied only to highly chromatic, low-gloss specimens upon agreement of users of this test method. The gloss value for glass of any other refractive index can be computed from the Fresnel equation 5.
For small differences in refractive index, however, the gloss value is a linear function of index, but the rate of change of gloss with index is different for each geometry. For example, glass of index 1. NOTE 3—Polished black glass has been reported to change in refractive index with time largely due to chemical contamination The original values can be restored by optical polishing with cerium oxide.
A wedge of high-purity quartz provides a more stable reference standard than glass. If the reading is not within To calibrate, adjust the instrument to read correctly the gloss of a highly polished standard, properly positioned and oriented, and then read the gloss of a working standard in the mid-gloss range.
If the instrument reading for the second standard does not agree within one unit of its assigned values, check cleanliness and repeat. If the instrument reading for the second standard still does not agree within one unit of its assigned value, repeat with another mid-range standard.
If the disparity is still more than one unit, do not use the instrument without readjustment, preferably by the manufacturer. For specimens with brush marks or similar texture effects, place them in such a way that the directions of the marks are parallel to the plane of the axes of the incident and reected beams.
If the range is greater than two gloss units, take additional readings and calculate the mean after discarding divergent results as in the section on Test for Outliers of Practice D For larger specimens, take a proportionately greater number of readings.
ASTM D Gloss_百度文库
To apply the correction, 3 Sold to: Such standards should be checked periodically for constancy by comparing with primary standards. Keep them clean and away from any dirt that might scratch or mar their surfaces. Never place standards face down on a surface that may be dirty or abrasive. Always hold standards at the side edges to avoid getting oil from the skin on the standard surface.
Clean the standards in warm water and a mild detergent solution brushing gently with a soft nylon brush. Do not use soap solutions to clean standards, because they can leave a lm.
Do not wipe standards. The polished black glass high-gloss standard may be dabbed gently with a lint-free paper towel or other lint-free absorbent material. Place the rinsed standards in a warm oven to dry.
Preparation and Selection of Test Specimens 8. To measure the correction, illuminate the specimen perpendicularly and view aztm the incident angle with the receiver aperture specied in 6. The luminous ux entering the receiver aperture from the perfect white diffusor would give the following gloss indications for each of the geometries: For means of three determinations. This does not include variability due to preparation of panels in different laboratories.
NOTE 5—For some types of paint, particularly semi-gloss, the measured gloss is affected by method of lm preparation and drying conditions so that the reproducibility of results from such materials may be poorer than the values given in Table 3.
Also, Journal of Research, Nat. Bureau Standards, Vol 18, No. Six somewhat different appearance attributes are shown to be variously associated with gloss.
Therefore, as many as six different photometric scales may be required to handle all gloss measurement problems. This paper is out of print. A comparison is made of several geometrically different photometric scales for separating paint nishes for gloss. The geometric conditions of test later incorporated in Test Method D are recommended.
History of Test Method D A study of the effect of aperture variation on glossmeter readings, including denitions of terms used in connection with specular gloss measurement, the Fresnel equation in a form readily usable for computation, and the deviation of diffuse correction formulas.
A study asttm the history of gloss methods in Qstm and other societies, describing the background in the choice of geometry of these methods. Contains photographs depicting gloss characteristics of a variety of methods. A study of the effect of geometric conditions on results of gloss tests with special attention to high-gloss panels.
Compares visual difference ratings with instrumental measurements of specular gloss, distinctness of image gloss, and haze for series of black, gray, and white painted specimens. The data are analyzed by multidimensional scaling. The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard.
Users of this standard are expressly advised that determination of the validity adtm any such patent rights, and the risk of infringement of such rights, are entirely their own responsibility. This standard is subject to revision at any time by the responsible technical committee and must be reviewed every ve years and if not revised, either atm or withdrawn. Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM Headquarters.
Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend.