ASTM D5767-95(2004)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D5767 − 95 (Reapproved2004)
Standard Test Methods for
Instrumental Measurement of Distinctness-of-Image Gloss
of Coating Surfaces
This standard is issued under the fixed designation D5767; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope D823Practices for Producing Films of Uniform Thickness
of Paint, Varnish, and Related Products on Test Panels
1.1 This test method describes the measurement of the
D2457Test Method for Specular Gloss of Plastic Films and
distinctness-of-image (DOI) gloss of coating surfaces using
Solid Plastics
electro-optical measuring techniques. The coatings must be
D3964Practice for Selection of Coating Specimens for
appliedtoplanarrigidsurfaces.Thescalevaluesobtainedfrom
Appearance Measurements
the alternative methods cited do not agree.
D4039Test Method for Reflection Haze of High-Gloss
1.2 Three test methods are covered as follows:
Surfaces
1.2.1 Test Method A—Gloss reflectance factor measure-
E284Terminology of Appearance
ments are made on the specimen at the specular viewing angle
E430TestMethodsforMeasurementofGlossofHigh-Gloss
and at an angle slightly off the specular viewing angle. The
Surfaces by Abridged Goniophotometry
values obtained are combined to provide a DOI value. Very
2.2 Other Standards:
narrow source and receptor aperture angles are used in the
ISO 10216Anodized Aluminum and Aluminum Alloys—
measurements.
Instrumental Determination of Image Clarity of Anodic
1.2.2 Test Method B—The light through a small slit is
Oxidation Coatings—Instrumental Method
projected on the specimen surface and its reflected image
intensity is measured through a sliding combed shutter to 3. Terminology
provide a value of image clarity.
3.1 Terms and Definitions in Terminology E284 are appli-
1.2.3 Test Method C—The light through a pattern is pro-
cable to these methods.
jectedonthespecimensurfaceanditsreflectedimageintensity
3.2 Definitions:
is measured directly to provide a value of image clarity.
3.2.1 distinctness-of-image gloss, n—aspect of gloss char-
1.3 This standard does not purport to address all of the
acterized by the sharpness of images of objects produced by
safety concerns, if any, associated with its use. It is the
reflection at a surface. E284
responsibility of whoever uses this standard to consult and
3.2.1.1 Discussion—This quality is sometimes called Image
establish appropriate safety and health practices and deter-
Clarity.
mine the applicability of regulatory limitations prior to use.
3.2.2 gloss reflectance factor, R ,n—ratio of the specularly
s
2. Referenced Documents
reflectedpartofthe(whole)fluxreflectedfromthespecimento
the flux reflected from a specified gloss standard under the
2.1 ASTM Standards:
same geometric and spectral conditions of measurements.
D523Test Method for Specular Gloss
E284
3.2.2.1 Discussion—The gloss standard may be a black
This test method is under the jurisdiction of ASTM Committee E12 on Color
glass or mirror and may be assigned one of a variety of scale
and Appearance and is the direct responsibility of Subcommittee E12.03 on
Geometry.
values as specified.
Current edition approved Nov. 1, 2004. Published November 2004. Originally
3.2.3 specular angle, n—the angle of reflection equal and
approved in 1995. Last previous edition approved in 1999 as D5767–95(1999).
DOI: 10.1520/D5767-95R04. opposite to the angle of incidence. E284
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
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the ASTM website. 4th Floor, New York, NY 10036, http://www.ansi.org.
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D5767 − 95 (2004)
TABLE 1 Angles and Dimensions of Source Image and Receptors
7.1.1 Geometric Conditions—The axis of the incident beam
Dimensions of Dimensions of the Dimensions of shall be 20 or 30° from the perpendicular to the specimen
Source Image at Viewed Area at the Viewed
surface. Provisions shall be made so that receptor settings will
Sample Plane, ° Sample Plane, ° Area DOI, °
be at the specular angle and at an angle of 0.2 to 0.4° off the
Center of window 20 or 30 20 or 30 0.3 ± 0.1
A specularangle.Suitableangulardimensionsoftheimageofthe
Width 0.44 0.38 0.14
B
Length 7.0 4.0 4.0
source aperture and angular dimensions of the receptor aper-
A
tures are given in Table 1.
In plane of the angle of reflection.
B
Across the plane of the angle of reflection.
7.1.2 Spectral Conditions—Themeasurementshallbemade
with visible radiation (light) to give results in accordance with
the CIE spectral luminous efficiency.
7.1.3 Polarization—The incident flux shall be unpolarized
4. Significance and Use
and the receptor shall be insensitive to the state of polarization
4.1 Animportantaspectoftheappearanceofglossycoating
of the reflected luminous flux.
surfaces is the distinctness (clarity) of images reflected by
them. The values obtained by the measuring procedures given
8. Reference Standards
inthesemethodsgenerallycorrelatewellwithvisualratingsfor
8.1 Primary Standard—Highly polished, planar black glass
DOI (image clarity).
witharefractiveindexof1.567fortheSodiumDLineshallbe
4.2 Although Test Methods D523 and D4039 are useful in
assigned a G value of 100 on the instrument reading scale.
s
characterizing some aspects of glossy appearance, they do not
8.2 Working Standard (Intermediate-Scale Standard)—
provide satisfactory ratings for DOI (image clarity).
Highly polished, planar black glass with a refractive index
4.3 The measurement conditions given conform to the
close to 1.527 may be used as a standard if its assigned value
conditions specified in Test Methods E430.
has been established by measurement against the primary
standard or by computation from its refractive index using the
4.4 The measurement conditions given in Test Methods B
Fresnel equation.
and C conform to the conditions specified in ISO 10216.
8.2.1 It shall be assigned a scale value of G =89.4 for a
s
4.5 The scale values obtained with the measuring proce-
specularangleof30°,or G =89.2foraspecularangleof20°.
s
duresofthesemethodsrangefrom0to100withavalueof100
representing perfect DOI (image clarity). NOTE 1—Each 0.01 increment in index of refraction produces a change
of approximately 3 units in the assigned scale value of polished black
4.6 The DOI (image clarity) scale value does not of itself,
glass for 20° geometry and a change of approximately 2.5 units in the
indicate any specific cause for reduction in reflected image
assigned scale value for 30° geometry.
NOTE 2—To determine the scale value, calculate the first surface
sharpness.Surfaceirregularitiessuchashaze,orangepeel,and
(Fresnel)reflectance(seeTestMethodD2457,5.1)for n =1.567andthe
D
wrinkle, when present, may be cited as causes for reduction of
specular angle of interest; for 30° it is 5.0436% and for 20° it is 4.90%.
image sharpness.
Assign this a scale value of 100 (see Test Method D523, 7.1). Repeat the
calculation for n =1.527 and the same specular angle; the result for 30°
D
5. Preparation and Selection of Test Specimens
is 4.5069% and for 20°, 4.3769%. The new scale value for 30° is
100×(4.5069/5.0436)=89.4, and for 20°, 100×(4.3769/4.9078)=89.2.
5.1 These test methods do not cover techniques for the
(The latter figure is identical to that given in Test Method D523 for the
preparation of test specimens. Whenever preparation of test
same angle.)
specimens is required, use one of the procedures given in
8.3 Verification Standards—Depolished opaque black glass
Practices D823. Selection of specimens for measurement
and ceramic tile having uniform, planar surfaces are suitable
should be done in accordance with Practice D3964.
when calibrated against a primary or working standard on an
abridged goniophotometer or gonioreflectometer known to
6. Correlation of Results of Test Methods A, B and C to
meet the requirements of Test Method A.
Visual Perception of Image Distinction of Coating
Surfaces
9. Standardization of Apparatus
6.1 Ananalysisoftheresultsofaroundrobinconductedby
9.1 Adjusttheinstrumenttoreadtheassignedscalevalueof
Task Group D01.26.11 demonstrates the level of correlation
thepolishedblackglassstandard.Takereadingsonverification
between instruments currently included in these test methods
standards whose assigned values cover the range of the
and with visual perception.
instrument scale. The readings of the verification standards
TEST METHOD A should agree within 61 unit of their assigned values.
7. Apparatus 10. Procedure
7.1 Abridged Goniophotometer or Gonioreflectometer,
10.1 Positionthespecimenontheinstrument.Placeaclamp
which can be set to the beam and aperture angles indicated in
orweightonthespecimentoflattenit.Takeareading, R,atthe
s
Table 1.
specular angle. Without moving the specimen, take a reading,
R , at a receptor angle of 0.2 to 0.4° off the specular angle.
os
10.2 Repeatthisprocedureonatleasttwootherareasofthe
Supporting data have been filed atASTM International Headquarters and may
be obtained by requesting Research Report RR:D01-1092. specimen.
D5767 − 95 (2004)
10.3 Take readings on the standards at the end of the series 13. Precision and Bias
of specimen readings to ensure that the instrument has re-
13.1 Precision—Precision data are not available. When an
mained in calibration throughout the operation.
interlaboratory test has been conducted, precision statements
will be established from the test results.
11. Calculation
13.2 Bias—Bias cannot be determined because there is no
11.1 Combine the specular angle reading, R , with the off
s
accepted reference procedure for determining true values.
specular reading, R , as follows:
os
TEST METHOD B
DOI 5 1 2 R /R 3100 (1)
@ ~ !#
os s
NOTE 3—Some instruments perform this calculation internally and
14. Apparatus
provide a direct reading of DOI.
14.1 Image Clarity Meter, consisting of a light source, a
sliding combed shutter, a photo-receiver, and a device for
12. Report
analyzing image intensities (see Fig. 1).
12.1 Report the following information:
14.2 Principle—The light through a small slit is projected
12.1.1 R ,
s
on the specimen surface, and its reflected image intensity
12.1.2 R ,
os
through a sliding combed shutter is measured.
12.1.3 Mean DOI,
12.1.4 I
...