ASTM D1684-07(2012)
(Practice)Standard Practice for Lighting Cotton Classing Rooms for Color Grading
Standard Practice for Lighting Cotton Classing Rooms for Color Grading
SIGNIFICANCE AND USE
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.
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 and health practices and determine the applicability of regulatory limitations prior to use.
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D1684 − 07 (Reapproved 2012)
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 (1,2,3), (as well as color matchers
in other industries (4,5,6)) has found in practice to be the minimum color temperature of preferred
daylight.
1. Scope 3. Terminology
1.1 This practice covers practices in general use in the
3.1 For all terminology relating to D13.11, Cotton and
United States for lighting cotton classing rooms, provides
Fibers, refer to Terminology D7139.
general background information regarding the development
3.1.1 The following terms are relevant to this standard:
and establishment of these practices, and prescribes a test
color grading, illumination, kelvin.
method for appraising the color quality of lamps procured for
3.2 For all other terminology relating to textiles, refer to
this purpose.
Terminology D123.
1.2 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
4. Summary of Practice
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
4.1 Artificial lighting is used in cotton classing rooms to
bility of regulatory limitations prior to use.
simulate ideal daylight conditions in north latitudes with a
moderately overcast sky. The quality and quantity of
2. Referenced Documents
illumination, the geometry of illumination, the type of lighting
2.1 ASTM Standards: unit and pattern for installation, the color of surroundings, and
D123 Terminology Relating to Textiles
maintenance of lighting equipment are specified in this prac-
D7139 Terminology for Cotton Fibers tice.
5. Significance and Use
ThispracticeisunderthejurisdictionofASTMCommitteeD13onTextilesand
is the direct responsibility of Subcommittee D13.11 on Cotton Fibers.
5.1 This practice is useful for establishing and maintaining
Current edition approved July 1, 2012. Published August 2012. Originally
standard lighting conditions in cotton classing rooms. This
approved in 1959 T. Last previous edition approved in 2007 as D1684 – 07. DOI:
permits the classer to make a valid assessment of the color
10.1520/D1684-07R12.
grade of cotton. The cotton classer attempts to classify cotton
The boldface numbers in parentheses refer to references listed at the end of this
practice.
on the basis of the color the sample and the standard would
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
have in daylight. It is essential that the lighting in a classing
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
room is constant and that it makes the color of cotton appear as
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. nearly as possible as it would in natural daylight.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D1684 − 07 (2012)
5.2 Uniform lighting conditions permit classers to go from spectral quality the spectral distribution shall be as close as
one classing room to another without having to make adjust- possible to that shown in Fig. 1; in no case shall the color
ments for wide differences in the amount and quality of renderingindexbelowerthan92,asdeterminedbytheGeneral
lighting. Color Rendering Index recommended in 1965 by the Interna-
tional Commission on Illumination (CIE) described in Refer-
6. Quality of Illumination
ences (9) and (10).
6.1 The standard for color quality of illumination is the
color and spectral quality of daylight of a moderately overcast 7. Quantity of Illumination
northern sky, as represented by the curve and data in Fig. 1 for
7.1 Atthepresenttime,theoptimumamountofillumination
typical daylight at 7500 K (7,8).
for cotton classing is not known. For light sources that include
6.2 Tolerances for meeting this standard for color quality the use of fluorescent lamps, the U.S. Department of Agricul-
are 6200 K correlated color temperature of color, and for ture requires at the time of installation a minimum of 100
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 (2012)
footcandles (1076 lx) on the working surface (from center to 9.2.1 Diffusing glass at the bottom of the units is set 10 ft (3
limits of classing areas). Studies (4,5,11) show that illumina- m) from the floor and parallel to it, in rows centered 6 ft (2.1
tion above 400 fc (4300 1x) may be considered “very poor.” m) apart.
Optimum conditions lie somewhere between. Most recent
9.2.2 A minimum of four rows are recommended for an
installationsarewellabovetheminimumrequirements,usually
averagesizedroom.Increasethenumberofrowsasrequiredto
reaching a range of 150 to 200 fc (1614 to 2152 lx) on
allowefficientuseofallspacewithintheroom.Classingtables,
installation (Notes 1 and 2).
depending somewhat on their length, may be placed either
parallel to the direction of lighting or at right angles. For full
NOTE 1—The minimum range for lighting cotton classing rooms is
use of the room, lighting units should be extended to within 3
based on data in Tables X1.1 and X1.2 in Appendix X1. Many cotton
classingroomswerestudied;theywerelightedbydaylightfromthenorth, to 4 ft (1 to 1.2 m) of the side walls and as close to end walls
usually through skylights. Results demonstrate that the absolute level of
as is convenient and possible.
lighting is not critical; the highest footcandles for each sky condition do
9.2.3 For a single table, no less than three units, installed
not always rate “very good.” Later studies corroborated the option, based
end-to-end, should be used; for a small classing room the
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 minimum is two rows of four units each.
illumination for classing. The data obtained seem to be the result of
averaging whatever quantities of illumination happened to be associated
10. Color of Surroundings
with the best liked quality of illuminant. For example, light from a clear
blueskyofteniscalledglaring,eventhoughtheamountofilluminationon
10.1 The color on walls, ceiling, floors, furniture, and even
clear days is well below that of slightly cloudy or overcast days.
of the cotton itself (if it covers a large area when laid out for
NOTE 2—There are reasonable wide limits within which the eye
classing) has a considerable effect on the lighting in a room,
operates satisfactorily in seeing color differences, and while more light is
both on the amount of light re
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.