ASTM E430-97(2003)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:E430–97(Reapproved2003)
Standard Test Methods for
Measurement of Gloss of High-Gloss Surfaces by
Goniophotometry
This standard is issued under the fixed designation E430; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope 3.1.1.1 reflectance, r,n—ratio of the reflected radiant or
luminous flux to the incident flux in the given conditions.
1.1 These test methods cover the measurement of the
(E284)
reflection characteristics responsible for the glossy appearance
(1) Discussion—The term reflectance is often used in a
of high-gloss surfaces. Two test methods, A and B, are
general sense or as an abbreviation for reflectance factor. Such
provided for evaluating such surface characteristics at specular
usage is not assumed in this method. The definition may
angles of 30° and 20°, respectively.These test methods are not
require that the term be modified by adjectives denoting the
suitable for diffuse finish surfaces nor do they measure color,
spectral and geometric conditions of measurement.
another appearance attribute.
3.1.1.2 reflectance factor, R, n—ratio of the flux reflected
1.2 As originally developed by Tingle and others (see Refs
2 from the specimen to the flux reflected from the perfect
1 and 2), the test methods were applied only to bright metals.
reflecting diffuser under the same spectral and geometric
Recently they have been applied to high-gloss automotive
conditions of measurement. (E284)
finishes and other nonmetallic surfaces.
3.1.1.3 gloss reflectance factor, R,n—ratio of the specu-
s
2. Referenced Documents larly reflected part of the (whole) flux reflected from the
specimen to the flux reflected from a specified gloss standard
2.1 ASTM Standards:
under the same geometric and spectral conditions of measure-
D523 Test Method for Specular Gloss
ment.
D2457 TestMethodforSpecularGlossofPlasticFilmsand
(1) Discussion—The gloss standard may be a black glass or
Solid Plastics
a mirror, and may be assigned one of a variety of scale values
E171 Specification for Standard Atmospheres for Condi-
G as specified. (E284)
tioning and Testing Flexible Barrier Materials s
3.1.2 Gloss and Types of Gloss:
E179 Guide for Selection of Geometric Conditions for
3.1.2.1 gloss, n—angular selectivity of reflected light, re-
Measurement of Reflectance and Transmission Properties
sponsibleforthedegreetowhichreflectedhighlightsorimages
of Materials
of objects may be seen as superimposed on a surface. (E284)
E284 Terminology of Appearance
(1) Discussion—Gloss is responsible for the object’s glossy
E308 Practice for Computing the Colors of Objects by
appearance,notforanobserver’sperceptionoftheappearance.
Using the CIE System
At least six types or characteristics of gloss may be observed
E1347 Test Method for Color and Color-Difference Mea-
depending upon the character of the surface and the spatial
surement by Tristimulus (Filler) Colormetry
distribution of the reflected light (3).
3. Terminology
3.1.2.2 specular gloss, n—ratio of flux reflected in specular
direction to incident flux for a specified angle of incidence and
3.1 Definitions:
source and receptor angular apertures. (E284)
3.1.1 Reflectance and Related Terms:
3.1.2.3 distinctness-of-image gloss, n—aspectofglosschar-
acterized by the sharpness of images of objects produced by
These test methods are under the jurisdiction of ASTM Committee E12 on
reflection at a surface. (E284)
Color andAppearance and are the direct responsibility of Subcommittee E12.03 on
3.1.2.4 sheen, n—the specular gloss at a large angle of
Geometry.
incidence for an otherwise matte specimen. (The usual angle
Current edition approved Jan. 10, 2003. Published March 2003. Originally
approved in 1971. Last previous edition approved in 1997 as E430–97. for measurement is 85°.) (E284)
The boldface numbers in parentheses refer to the list of references at the end of
3.1.3 Terms Relating to Surface Characteristics:
this method.
Annual Book of ASTM Standards, Vol 06.01.
Annual Book of ASTM Standards, Vol 08.02.
Annual Book of ASTM Standards, Vol 15.09.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E430–97 (2003)
3.1.3.1 directionality, n—perceived, the degree to which the 5. Significance and Use
appearance of a surface changes as the surface is rotated in its
5.1 Theglossofmetallicfinishesisimportantcommercially
ownplane,underfixedconditionsofilluminationandviewing.
on metals for automotive, architectural, and other uses where
(E284)
thesemetalsundergospecialfinishingprocessestoproducethe
3.1.3.2 texture, n—the visible surface structure depending
appearancesdesired.Itisimportantfortheend-productswhich
on the size and organization of small constituent parts of a
use such finished metals that parts placed together have the
material; typically, the surface structure of a woven fabric.
same glossy appearance.
(E284)
5.2 It is also important that automotive finishes and other
3.1.4 Other Terms:
high-gloss nonmetallic surfaces possess the desired finished
3.1.4.1 aperture angle, 2 ,n—anglesubtendedatapointon appearance. The present method identifies by measurements
k
a specimen by the maximum dimension of the illuminator or important aspects of finishes. Those having identical sets of
receiver, within which the flux in a directional beam is numbers normally have the same gloss characteristics. It
contained. usually requires more than one measurement to identify
properlytheglossyappearanceofanyfinish(seeRefs 3and 4).
(1) Discussion—In optics, the symbol k is used for the half
angle; hence the recommended symbol here is 2.(E284)
k
6. Apparatus
3.1.4.2 goniophotometer, n—instrument that measures flux
6.1 The apparatus shall be either an abridged goniophotom-
as a function of angles of illumination or observation. (E284)
eter (see Fig. 1 and Fig. 2) or a full goniophotometer (see Fig.
3.2 Terms Specific to This Test Method:
3) that can be set to the specified specular, off-specular, and
3.2.1 Terms Relating to Reflection Haze:
aperture angles given in Table 1 and Table 2. The abridged
3.2.1.1 reflection haze, H, n—for a specified specular angle,
goniophotometer may have a fixed angle of incidence (forTest
ratio of flux reflected at a specified angle (or angles) from the
Method A, 30°; for Test Method B, 20°) and specific fixed
specular direction to the flux similarly reflected at the specular
directions of view at which the flux from the specimen is
angle by a specified gloss standard.
measured (see Table 1 and Table 2).
(1) Discussion—Modifiersmaybeusedtospecifytheangles
6.1.1 Geometric Conditions for Test Method A—The direc-
at which the haze is measured (for example, 2° or 5°); whether
tion of incidence shall be 30°. The directions of view shall be
H or a logarithmic form is to be stated; or whether H is to be
opposite the direction of incidence at 30° for specular reflec-
compensated for the luminance of the specimen by multipli-
tance, 29.7 or 30.3° for distinctness of image comparisons, 28
cation by Y /Y , where n denotes the reference white; or
specimen n
or 32° for narrow-angle haze comparisons, and 25 or 35° for
any combination of these.
wide-angle haze comparisons. The angular dimensions of the
3.2.2 Terms Relating to Metallic Reflection:
mirror reflected image of the source slit in the plane of
3.2.2.1 metallic brightness, n—freedom of a metal surface
measurement and the angular dimensions of the receiver
from diffuse haze or texture.
windows in this plane of measurement shall be as shown in
3.2.3 Terms Relating to Specimen Directionality: Table 1.
3.2.3.1 ‘with-machine’direction, n—the axis of a specimen 6.1.2 Geometric Conditions for Test Method B—The direc-
tion of incidence shall be 20 6 0.1°. The directions of view
that is parallel to the direction of mill rolling or extrusion, or
other surface-finish texture. shall be opposite the direction of incidence, at 20° for specular
gloss measurement and at 18.1 and 21.9° for narrow-angle
3.2.3.2 ‘across-machine’ direction, n—the perpendicular to
reflection haze measurement. The angular dimensions of the
‘with-machine’ direction.
specularly reflected image of the source slit in the plane of
3.3 Other appearance terms and definitions in Terminology
measurement and the angular dimensions of the receiver
E284 are applicable to this test method.
windows in this plane of measurement shall be as shown in
Table 2.
4. Summary of Test Method
6.1.3 Spectral Conditions—Themeasurementshallbemade
4.1 Several geometrically different measures of light re-
with visible light to give results in accordance with the CIE
flected by a surface are proposed for use in describing its gloss
spectral luminous efficiency function V (l identical with y¯) in
appearance. In Test Method A, gloss reflectance factor is
the CIE 1931 standard observer and CIE standard illuminant C
measured at 30° to the specimen normal using narrow illumi-
(see Practice E308 and Test Method E1347). If another
nator and receiver aperture angles (0.5° wide maximum).
illuminant A, is used, this shall be specified in the report.
Distinctness-of-image gloss is measured at 29.7 or 30.3° or
6.1.4 Polarization—The incident flux shall be unpolarized
both. Narrow-angle (2°) reflection haze is measured at 28 or
and the receiver shall be insensitive to the state of polarization
32° or both, and wide-angle (5°) reflection haze at 25 or 35° or
of the reflected luminous flux.
both. The ratio of reflectance factors for 28 or 32° or both,
perpendicular and parallel to the machine direction of the
specimen, is computed as a measure of directionality. In
The sole source of supply of the apparatus known to the committee at this time
for Method A is Hunter Associates Laboratory, Reston, VA, and for Method B is
Method B, specular gloss is measured at 20° according to Test
BVK-Gardner USA, Columbia, MD. If you are aware of alternative suppliers,
MethodD523,andnarrow-anglereflectionhazeismeasuredat
please provide this information to ASTM International Headquarters. Your com-
18.1 and 21.9°. For additional information on the selection of
ments will receive careful consideration at a meeting of the responsible technical
geometric conditions, see Guide E179. committee, which you may attend.
E430–97 (2003)
FIG. 1 Optical Diagram of the Abridged Goniophotometer
and the specular angle of interest; for 30° it is 5.0436% and for 20° it is
6.1.5 Clamp—For Test Method A, a rotatable clamp of the
4.9078%. Assign this a scale value of 100 (Test Method D523, Section
typeshowninFig.4maybeusedforflatteningandpositioning
7.1). Repeat the calculation for n =1.527 and the same specular angle;
the specimen during measurement. p
the result for 30° is 4.5069% and for 20°, 4.3769%.The new scale value
for 30° is 100 3(4.5069/5.0436)=89.4, and for 20°, 100 3(4.3769/
7. Standards
4.9078)=89.2. (The latter value is also given in Test Method D523.)
7.1 Three calibrated standards of good planarity shall be
available in either a set of metals or a set of nonmetals, 7.3 Intermediate Standards:
depending upon which type of surface is measured.
7.3.1 Intermediate Standard for Metals shall be of either
7.2 High-Gloss Standards:
chromium evaporated onto glass and covered with a protective
7.2.1 High-Gloss Standard for Metals shall be of alumi-
coating of silicon monoxide, or of bright sheet aluminum with
num, evaporated onto glass and covered with a protective
protective coating and calibrated for specular gloss and
coating of silicon monoxide, and calibrated for specular gloss
distinctness-of-image gloss.
and distinctness-of-image gloss.
7.3.2 Intermediate Standard for Nonmetals shall be of a
7.2.2 High-Gloss Standard for Nonmetals shallbeofhighly
ceramic material, such as porcelain enamel on steel, and
polished black glass with a refractive index of approximately
calibrated for specular gloss and distinctness-of-image gloss.
n =1.527, calibrated for specular gloss and reflection haze,
D
7.4 Diffuse Standards shall have a reflectance factor sub-
and assigned a scale value of G =89.4 for a specular angle of
s
30° (Test Method A) or G =89.2 for a specular angle of 20° stantially constant over the angular range of the instrument.
s
(Test Method B).
7.5 Care of Standards—It is essential that the standards be
kept clean and free of scratches as well as from contact with
NOTE 1—To determine the scale value, calculate the first-surface
(Fresnel) reflectance (Test Method D2457, Section 5.1) for n =1.567 contaminating materials.The cleaning method specified by the
D
E430–97 (2003)
of specular gloss and distinctness-of-image gloss assigned the
aluminum mirror if metal surfaces are being measured; or the
black gloss standard if nonmetal surfaces are being measured.
If the instrument does not then read the appropriate interme-
diate standard within the limits set by the instrument manufac-
turer, refocus or restandardize following the manufacturer’s
instructions.
10. Procedure
10.1 Bringthespecimentotheinstrumentformeasurement.
Be sure the specimen is flat.
10.2 For Test MethodA, be certain that the specular sensor
is centered on the specimen-reflected specular light beam. The
full goniophotometer, shown in Fig. 3, identifies the specular
direction by the peak of the goniophotometric curve.
10.3 Rotate the specimen in its own plane to find the
orientation, giving the maximum specular signal. This speci-
men orientation is called the “machine direction” because it
generally coincides with the direction of travel of a sheet or
film material through a processing machine.
10.4 Record the following quantities:
10.4.1 For Test Method A, readings of (a) gloss reflectance
factor (specular gloss), R at 30°; (b) distinctness-of-image
s,30
gloss; (c) 2° reflection haze; H ; and (d) 5° reflection haze, H .
2 5
The quantities in (b), (c), and (d) may be either gloss
reflectance factors or values of H, which are their ratios to the
specular gloss reflectance factor recorded in (a).
10.4.2 For Test Method B, readings of (a) the 20° specular
gloss, R ; (b) the reflection haze, H; and (c) the luminous
s ,20
reflectance, Y.
10.5 Measure at least three areas of each specimen.
10.6 From these same areas, read 2° haze for the“ across-
machine direction,” being careful to flatten the test surface and
FIG. 2 Optical Diagram of the Apparatus for Method B
orient the specular beam in each case.
10.7 Take readings on the standards at the end of the series
of observations to ensure that the instrument h
...