ASTM D1684-07(2020)
(Practice)Standard Practice for Lighting Cotton Classing Rooms for Color Grading
Standard Practice for Lighting Cotton Classing Rooms for Color Grading
SIGNIFICANCE AND USE
5.1 This practice is useful for establishing and maintaining standard lighting conditions in cotton classing rooms. This permits the classer to make a valid assessment of the color grade of cotton. The cotton classer attempts to classify cotton on the basis of the color the sample and the standard would have in daylight. It is essential that the lighting in a classing room is constant and that it makes the color of cotton appear as nearly as possible as it would in natural daylight.
5.2 Uniform lighting conditions permit classers to go from one classing room to another without having to make adjustments for wide differences in the amount and quality of lighting.
SCOPE
1.1 This practice covers practices in general use in the United States for lighting cotton classing rooms, provides general background information regarding the development and establishment of these practices, and prescribes a test method for appraising the color quality of lamps procured for this purpose.
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Relations
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D1684 − 07 (Reapproved 2020)
Standard Practice for
Lighting Cotton Classing Rooms for Color Grading
This standard is issued under the fixed designation D1684; 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 (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
Until 1940, practically all cotton classing was done in daylight, much of it in specially skylighted
rooms designed to provide sufficient and uniform lighting on the classing tables. Cotton classification
or classing is the art and science of describing the quality of cotton according to the official standards
of the United States. Grade is divided into two categories – color grade and leaf grade. Because color
grade is an important quality factor in establishing the price and use of cotton, the color quality of
lighting is important. The cotton classer attempts to class cotton on the basis of the color the sample
and the standard would have in daylight. In classing rapidly he refers to physical standards only
occasionally each day; therefore it is most important that the lighting in a classing room shall not only
provide a constant color but that it shall make the color of cotton appear as nearly as possible as it
would in daylight so that he can take full advantage of training and memory.
In the USA, daylight at about 7500 K is what the cotton classer (1-3), (as well as color matchers
in other industries (4-6)) has found in practice to be the minimum color temperature of preferred
daylight.
1. Scope 2. Referenced Documents
1.1 This practice covers practices in general use in the 2.1 ASTM Standards:
United States for lighting cotton classing rooms, provides D123 Terminology Relating to Textiles
general background information regarding the development D7139 Terminology for Cotton Fibers
and establishment of these practices, and prescribes a test
3. Terminology
method for appraising the color quality of lamps procured for
3.1 For all terminology relating to D13.11, Cotton and
this purpose.
Fibers, refer to Terminology D7139.
1.2 This standard does not purport to address all of the
3.1.1 The following terms are relevant to this standard:
safety concerns, if any, associated with its use. It is the
color grading, illumination, kelvin.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter- 3.2 For all other terminology relating to textiles, refer to
mine the applicability of regulatory limitations prior to use. Terminology D123.
1.3 This international standard was developed in accor-
4. Summary of Practice
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the 4.1 Artificial lighting is used in cotton classing rooms to
Development of International Standards, Guides and Recom- simulate ideal daylight conditions in north latitudes with a
mendations issued by the World Trade Organization Technical moderately overcast sky. The quality and quantity of
Barriers to Trade (TBT) Committee. illumination, the geometry of illumination, the type of lighting
unit and pattern for installation, the color of surroundings, and
maintenance of lighting equipment are specified in this prac-
ThispracticeisunderthejurisdictionofASTMCommitteeD13onTextilesand
tice.
is the direct responsibility of Subcommittee D13.11 on Cotton Fibers.
Current edition approved July 1, 2020. Published August 2020. Originally
approved in 1959 T. Last previous edition approved in 2012 as D1684 – 07(2012). For referenced ASTM standards, visit the ASTM website, www.astm.org, or
DOI: 10.1520/D1684-07R20. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
The boldface numbers in parentheses refer to references listed at the end of this
Standards volume information, refer to the standard’s Document Summary page on
practice.
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D1684 − 07 (2020)
5. Significance and Use 6. Quality of Illumination
5.1 This practice is useful for establishing and maintaining 6.1 The standard for color quality of illumination is the
standard lighting conditions in cotton classing rooms. This color and spectral quality of daylight of a moderately overcast
permits the classer to make a valid assessment of the color northern sky, as represented by the curve and data in Fig. 1 for
grade of cotton. The cotton classer attempts to classify cotton typical daylight at 7500 K (7, 8).
on the basis of the color the sample and the standard would
6.2 Tolerances for meeting this standard for color quality
have in daylight. It is essential that the lighting in a classing
are 6200 K correlated color temperature of color, and for
room is constant and that it makes the color of cotton appear as
spectral quality the spectral distribution shall be as close as
nearly as possible as it would in natural daylight.
possible to that shown in Fig. 1; in no case shall the color
5.2 Uniform lighting conditions permit classers to go from renderingindexbelowerthan92,asdeterminedbytheGeneral
one classing room to another without having to make adjust- Color Rendering Index recommended in 1965 by the Interna-
ments for wide differences in the amount and quality of tional Commission on Illumination (CIE) described in Refs (9)
lighting. and (10).
Wave- CIE Standard
A
length, nm for Daylight at
B
7500 K (Rela-
tive Energy)
400 101.9
10 111.9
20 112.8
30 103.1
40 121.2
450 133.0
60 132.4
70 127.3
80 126.8
90 117.8
500 116.6
10 113.7
20 108.7
30 110.4
40 106.3
550 104.9
60 100.0
70 95.6
80 94.2
90 87.0
600 87.2
10 86.1
20 83.6
30 78.7
40 78.4
650 74.8
60 74.3
70 75.4
80 71.6
90 63.9
700 65.1
A −9
nm is the abbreviation for nanometre, which is a metre × 10 = mµ = millimicron.
B
The data for 400 to 700 nm are based on Table III of August, 1965, recommendations of the CIE colorimetry committee (E-1.3.1) for an international standard to represent
typical daylight (300 to 830 nm) of correlated color temperature 7500 K (7, 8).
FIG. 1 Standard for Color Quality of Illumination for Color Grading Problems in Which the Equivalent of Light from a “Covered Sky” is
Required or Preferred. In North Latitudes this is a sky that is moderately overcast from the north.
D1684 − 07 (2020)
7. Quantity of Illumination diffusing glass designed not only to diffuse the light but to
provide a very low brightness contrast. Based on the pattern of
7.1 Atthepresenttime,theoptimumamountofillumination
light provided by these units, installations in which they are
for cotton classing is not known. For light sources that include
used usually are arranged as follows:
the use of fluorescent lamps, the U.S. Department of Agricul-
9.2.1 Diffusing glass at the bottom of the units is set 10 ft (3
ture requires at the time of installation a minimum of 100
m) from the floor and parallel to it, in rows centered 6 ft (2.1
footcandles (1076 lx) on the working surface (from center to
m) apart.
limits of classing areas). Studies (4, 5, 11) show that illumina-
9.2.2 A minimum of four rows are recommended for an
tion above 400 fc (4300 1x) may be considered “very poor.”
averagesizedroom.Increasethenumberofrowsasrequiredto
Optimum conditions lie somewhere between. Most recent
allowefficientuseofallspacewithintheroom.Classingtables,
installationsarewellabovetheminimumrequirements,usually
depending somewhat on their length, may be placed either
reaching a range of 150 to 200 fc (1614 to 2152 lx) on
parallel to the direction of lighting or at right angles. For full
installation (Notes 1 and 2).
use of the room, lighting units should be extended to within 3
NOTE 1—The minimum range for lighting cotton classing rooms is
to 4 ft (1 to 1.2 m) of the side walls and as close to end walls
based on data in Tables X1.1 and X1.2 in Appendix X1. Many cotton
as is convenient and possible.
classingroomswerestudied;theywerelightedbydaylightfromthenorth,
9.2.3 For a single table, no less than three units, installed
usually through skylights. Results demonstrate that the absolute level of
end-to-end, should be used; for a small classing room the
lighting is not critical; the highest footcandles for each sky condition do
not always rate “very good.” Later studies corroborated the option, based
minimum is two rows of four units each.
on a study of Tables X1.1 and X1.2, that after a minimum is reached, the
quality of the illumination is more important than quantity in choice of
10. Color of Surroundings
illumination for classing. The data obtained seem to be the result of
averaging whatever quantities of illumination happened to be associated
10.1 The color on walls, ceiling, floors, furniture, and even
with the best liked quali
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