1、Designation: D 1684 07Standard Practice forLighting Cotton Classing Rooms for Color Grading1This standard is issued under the fixed designation D 1684; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A nu
2、mber in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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 sufficient
3、 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; the
5、refore 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 wha
6、t the 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 backgro
7、und information 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 theresponsibil
8、ity of the user 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:3D 123 Terminology Relating to TextilesD 7139 Terminology for Cotton Fibers3. Terminology3.1 For al
9、l terminology relating to D13.11, Cotton andFibers, refer to Terminology D 7139.3.1.1 The following terms are relevant to this standard:color grading, illumination, kelvin.3.2 For all other terminology relating to textiles, refer toTerminology D 123.4. Summary of Practice4.1 Artificial lighting is u
10、sed in cotton classing rooms tosimulate ideal daylight conditions in north latitudes with amoderately overcast sky. The quality and quantity of illumina-tion, the geometry of illumination, the type of lighting unit andpattern for installation, the color of surroundings, and mainte-nance of lighting
11、equipment are specified in this practice.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 c
12、ottonon the basis of the color the sample and the standard wouldhave in daylight. It is essential that the lighting in a classing1This practice is under the jurisdiction ofASTM Committee D13 on Textiles andis the direct responsibility of Subcommittee D13.11 on Cotton Fibers.Current edition approved
13、Jan. 1, 2007. Published January 2007. Originallyapproved in 1959 T. Last previous edition approved in 2002 as D 1684 90(2002).2The boldface numbers in parentheses refer to references listed at the end of thispractice.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact AST
14、M Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.room is constant and that it
15、makes the color of cotton appear asnearly as possible as it would in natural daylight.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
16、 standard for color quality of illumination 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 temp
17、erature 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 in 1965 by the Interna-tional Commission on Illumination
18、 (CIE) described in Refer-ences (9) and (10).7. Quantity of Illumination7.1 At the present time, the optimum amount of illuminationfor cotton classing is not known. For light sources that includeWave-length, nmACIE Standardfor Daylight at7500 KB(Rela-tive Energy)400 101.910 111.920 112.830 103.140 1
19、21.2450 133.060 132.470 127.380 126.890 117.8500 116.610 113.720 108.730 110.440 106.3550 104.960 100.070 95.680 94.290 87.0600 87.210 86.120 83.630 78.740 78.4650 74.860 74.370 75.480 71.690 63.9700 65.1Anm is the abbreviation for nanometre, which is a metre 3 109= m = millimicron.BThe data for 400
20、 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 torepresent 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 Pr
21、oblems 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.D1684072the use of fluorescent lamps, the U.S. Department of Agricul-ture requires at the time of installation a minimum of 100footcandles
22、4(1076 lx) on the working surface (from center tolimits of classing areas). Studies (4,5,11) show that illumina-tion above 400 fc (4300 1x) may be considered “very poor.”Optimum conditions lie somewhere between. Most recentinstallations are well above the minimum requirements, usuallyreaching a rang
23、e of 150 to 200 fc (1614 to 2152 lx) oninstallation (Notes 1 and 2).NOTE 1The minimum range for lighting cotton classing rooms isbased on data in Tables X1.1 and X1.2 in Appendix X1. Many cottonclassing rooms were studied; they were lighted by daylight from the north,usually through skylights. Resul
24、ts demonstrate that the absolute level oflighting is not critical; the highest footcandles for each sky condition donot always rate “very good.” Later studies corroborated the option, basedon a study of Tables X1.1 and X1.2, that after a minimum is reached, thequality of the illumination is more imp
25、ortant than quantity in choice ofillumination for classing. The data obtained seem to be the result ofaveraging whatever quantities of illumination happened to be associatedwith the best liked quality of illuminant. For example, light from a clearblue sky often is called glaring, even though the amo
26、unt of illumination onclear days is well below that of slightly cloudy or overcast days.NOTE 2There are reasonable wide limits within which the eyeoperates satisfactorily in seeing color differences, and while more light isneeded to distinguish dark than light colors, originally only minimums forthe
27、 range of footcandles to be required on the classing tables werespecified for lighting cotton classing rooms since it was assumed thatadded costs would not encourage the use of higher illumination levels.Studies reported in 1958 by Blackwell to the Illuminating EngineeringSociety, summarized by Crou
28、ch (12) and by the I.E.S. Committee onQuality and Quantity of Illumination (13), indicate that many of theminimums to which we have become accustomed should be higher.Experience corroborates this.8. Geometry of Illumination8.1 The lighting should be generally diffused but withenough direction to all
29、ow a perception of depth as a classerlooks into his sample. It should be as uniform over all workingareas of the room as is possible; there should be no glare andno crosslighting, and the brightness contrast of the light sourceand its surroundings should be held at a minimum.9. Type of Unit and Patt
30、ern for Installation9.1 Lighting units should be designed to supply the requiredamount and color of illumination over the surface of a classingtable when units are placed end-to-end over the tables. Instal-lation requirements should be based on the pattern of illumi-nation provided by the lighting u
31、nits used, calculated so thatthe illumination will be as uniform as possible throughout theclassing room. Units should be closed, they should be as lightin weight as practical, and be easy to install, inspect, andmaintain in good order. It is recommended that air conditioningbe specified along with
32、these lighting installations (3).9.2 In classing room installations that meet the specifica-tions of this recommendation, units about 2 by 4 ft (0.6 by 1.2m) are widely used. They include use of spectrally neutraldiffusing glass designed not only to diffuse the light but toprovide a very low brightn
33、ess contrast. Based on the pattern oflight provided by these units, installations in which they areused usually are arranged as follows:9.2.1 Diffusing glass at the bottom of the units is set 10 ft (3m) from the floor and parallel to it, in rows centered 6 ft (2.1m) apart.9.2.2 A minimum of four row
34、s are recommended for anaverage sized room. Increase the number of rows as required toallow efficient use of all space within the room. Classing tables,depending somewhat on their length, may be placed eitherparallel to the direction of lighting or at right angles. For fulluse of the room, lighting
35、units should be extended to within 3to 4 ft (1 to 1.2 m) of the side walls and as close to end wallsas is convenient and possible.9.2.3 For a single table, no less than three units, installedend-to-end, should be used; for a small classing room theminimum is two rows of four units each.10. Color of
36、Surroundings10.1 The color on walls, ceiling, floors, furniture, and evenof the cotton itself (if it covers a large area when laid out forclassing) has a considerable effect on the lighting in a room,both on the amount of light reflected and on brightnesscontrasts that may be involved.10.2 Classing
37、rooms should be painted a neutral color (Note3) so that no one chromatic color will be enhanced ordiscounted more than another. Neutral colors cover a rangefrom white through a series of grays to black. All grays used inthe classing room should be truly neutral, that is, show no traceof any hue, and
38、 the lightness of the gray should depend on theamount of light coming into the room and reaching the classingsurface.NOTE 3The grays are specified in terms of the Munsell Neutral ValueScale, which consists of a series of neutral grays in visually equal stepsfrom black, at 0/, to white; at 10/. Munse
39、ll Neutral 7.0/ is a light gray; 8.0/and 8.5/ are lighter grays; while 9.5/ is very good white.510.3 For rooms with artificial lighting, such as those lightedwith wall-to-wall lighting units, the surroundings should be avery light neutral gray, no darker than Munsell Neutral 8.5/, inorder to conserv
40、e the lighting and to reduce brightness con-trasts as much as possible.10.4 The following color specifications are those used bythe U.S. Department of Agriculture for surroundings in cottonclassing rooms:10.4.1 Walls, no darker than Munsell Neutral 9.0/.10.4.2 Ceilings, white, or as near white as po
41、ssible, in nocase darker than Munsell Neutral 9.5/.10.4.3 Mats on which a classer stands should be black.10.4.4 Tables for Classing, light gray, with black top.10.4.5 Papers in which samples are wrapped should not beallowed to cover large areas of the field of view. Extra areas ofpaper should be fol
42、ded under the cotton to avoid this. Becauseof its naturally yellowish red hue, cotton will appear creamieragainst blue papers and grayer against brown papers than whenviewed against a neutral background.4One footcandle = 10.76391 lux; 1 lux = 0.0929 fc.5An inexpensive neutral gray color scale in 18
43、steps may be obtained from theMunsell Color Co., 2441 N. Calvert St., Baltimore, MD 21218.D168407311. Maintenance of Lighting Equipment11.1 Lamps and equipment must be properly maintained inorder to hold to proper and uniform levels of lighting. It is notenough to install good lighting; it must be m
44、aintained. Thefollowing routine should be followed:11.1.1 Daily inspection to check that all lamps are in goodorder.11.1.2 Prompt replacement of deficient lamps by the propertype of lamp.11.1.3 Use of a footcandle meter6to chart and recordfootcandle levels throughout all classing areas. The level of
45、these data should be watched throughout the year to determinechanges in illumination. Records of this sort, kept over a periodof years, are a help in setting up definite cleaning andreplacement schedules.11.1.4 Regular cleaning of fixtures, recording footcandlelevels before and after cleaning.11.1.5
46、 In fixtures that include use of fluorescent lamps,regular inspection of ballasts, at least once each year. Lowvoltage or lack of ventilation above the lighting units tends tocause the ballast to overheat and bleed. In fact, ballast troublecan cause considerable variation in light output.12. Keyword
47、s12.1 cotton; colorREFERENCES(1) Nickerson, D., “Artificial Daylighting for Color Grading of Agri-cultural Products,” Journal, Optical Society of America, JOSAA, Vol29, 1939, pp. 19.(2) Nickerson, D., “The Illuminant in Color Matching and Discrimination:How Good a Duplicate is One Illuminant for Ano
48、ther,” IllumninatingEngineering, ILLEA, Vol 36, 1941, pp. 373399.(3) Nickerson, D., “Achievement of Lighting Standards for the Grading ofCotton,” U.S. Dept. of Agriculture AMS-94, Feb. 1956, 29 pp., andProceedings, Marketing Section, PMSAA, Association of SouthernAgricultural Workers, 53rd Annual Co
49、nvention.(4) Nickerson, D., “The Illuminant in Textile Color Matching: An Illumi-nant to Satisfy Preferred Conditions of Daylight-Match,” IlluminatingEngineering, ILLEA, Vol 43, 1948, pp. 416464.(5) Nickerson, D., “The Illuminant in Textile Color Matching: Summary,”Journal, Optical Society of America, JOSAA, Vol 38, 1948, pp.458466.(6) Nickerson, D., “Light Sources and Color Rendition,” Journal, OpticalSociety of America, JOSAA, Vol 59, 1960, pp. 5769.(7) CIE Committee E1.3.1 (Colorimetry), “Recommendations on StandardIlluminants for Colorimetry,” Table II of official rec
