1、Designation:D168407(Reapproved 2012)Standard Practice forLighting Cotton Classing Rooms for Color Grading1This standard is issued under the fixed designation D1684;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revi
2、sion.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.INTRODUCTIONUntil 1940,practically all cotton classing was done in daylight,much of it in specially skylightedrooms designed to provide suffici
3、ent and uniform lighting on the classing tables.Cotton classificationor classing is the art and science of describing the quality of cotton according to the official standardsof the United States.Grade is divided into two categoriescolor grade and leaf grade.Because colorgrade is an important qualit
4、y factor in establishing the price and use of cotton,the color quality oflighting is important.The cotton classer attempts to class cotton on the basis of the color the sampleand the standard would have in daylight.In classing rapidly he refers to physical standards onlyoccasionally each day;therefo
5、re it is most important that the lighting in a classing room shall not onlyprovide a constant color but that it shall make the color of cotton appear as nearly as possible as itwould in daylight so that he can take full advantage of training and memory.In the USA,daylight at about 7500 K is what the
6、 cotton classer(1,2,3),2(as well as color matchersin other industries(4,5,6)has found in practice to be the minimum color temperature of preferreddaylight.1.Scope1.1 This practice covers practices in general use in theUnited States for lighting cotton classing rooms,providesgeneral background inform
7、ation regarding the developmentand establishment of these practices,and prescribes a testmethod for appraising the color quality of lamps procured forthis purpose.1.2 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the use
8、r of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:3D123 Terminology Relating to TextilesD7139 Terminology for Cotton Fibers3.Terminology3.1 For all terminology rela
9、ting to D13.11,Cotton andFibers,refer to Terminology D7139.3.1.1 The following terms are relevant to this standard:color grading,illumination,kelvin.3.2 For all other terminology relating to textiles,refer toTerminology D123.4.Summary of Practice4.1 Artificial lighting is used in cotton classing roo
10、ms tosimulate ideal daylight conditions in north latitudes with amoderately overcast sky.The quality and quantity ofillumination,the geometry of illumination,the type of lightingunit and pattern for installation,the color of surroundings,andmaintenance of lighting equipment are specified in this pra
11、c-tice.5.Significance and Use5.1 This practice is useful for establishing and maintainingstandard lighting conditions in cotton classing rooms.Thispermits the classer to make a valid assessment of the colorgrade of cotton.The cotton classer attempts to classify cottonon the basis of the color the sa
12、mple and the standard wouldhave in daylight.It is essential that the lighting in a classingroom is constant and that it makes the color of cotton appear asnearly as possible as it would in natural daylight.1This practice is under the jurisdiction ofASTM Committee D13 on Textiles andis the direct res
13、ponsibility of Subcommittee D13.11 on Cotton Fibers.Current edition approved July 1,2012.Published August 2012.Originallyapproved in 1959 T.Last previous edition approved in 2007 as D1684 07.DOI:10.1520/D1684-07R12.2The boldface numbers in parentheses refer to references listed at the end of thispra
14、ctice.3For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C7
15、00,West Conshohocken,PA 19428-2959.United States1 5.2 Uniform lighting conditions permit classers to go fromone classing room to another without having to make adjust-ments for wide differences in the amount and quality oflighting.6.Quality of Illumination6.1 The standard for color quality of illumi
16、nation is thecolor and spectral quality of daylight of a moderately overcastnorthern sky,as represented by the curve and data in Fig.1 fortypical daylight at 7500 K(7,8).6.2 Tolerances for meeting this standard for color qualityare 6200 K correlated color temperature of color,and forspectral quality the spectral distribution shall be as close aspossible to that shown in Fig.1;in no case shall the colorrendering index be lower than 92,as determined by the GeneralColor Rendering Index recommended
