1、Designation: D3025 07 (Reapproved 2012)Standard Practice forStandardizing Cotton Fiber Test Results by Use ofCalibration Cotton Standards1This standard is issued under the fixed designation D3025; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、 of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers the use of reference standardcottons for the standardization of instrum
3、ents and techniquesused to test cotton fibers in various laboratories.1.2 Standardization may be achieved by application of acorrection factor based on the reference standards, or bymodification of the technique in use.NOTE 1When reference standards are used to develop correctionfactors, or to adjus
4、t an operators technique, no instrument calibrationprocesses are involved. The term “Calibration” is properly used for theapplication or assignment of permanent scales or marks to an instrument.Adjustments can be made to specific instruments and accessories such asorifices, metallic strips, or cello
5、phane sheets, in order to obtain theprescribed values with a specific instrument. Since an operators techniqueor the interpretation of a method or procedure is inherently variable, itcannot be calibrated, that is, assigned a permanent, definite value. The useof reference standards, however, affords
6、a means for standardizingtechniques and checking the reliability of observed results.1.3 This practice recognizes two types of reference stan-dards: (1) calibration cotton standards (see 6.1) and (2)working cotton standards (see 6.2).1.4 The instructions included in this practice can be usedwith cot
7、ton fibers in any form suitable for testing with theparticular instrument to be used.1.5 The instructions in the practice are applicable to cottonfibers but can also be applied to specific blends of cotton andother fibers, or to other fibers that can be tested with theinstruments designed for testin
8、g cotton fibers. No informationis available, however, to show that test procedures standardizedwith reference cotton samples are equally reliable with variouscotton fiber blends or with other fibers.NOTE 2Standardization procedures covered in this practice are rec-ommended for use with the following
9、: Test Methods D1440, D1445,D1447, and D1448.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to consult andestablish appropriate safety and health practices and deter-mine the applicability
10、 of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D123 Terminology Relating to TextilesD1440 Test Method for Length and Length Distribution ofCotton Fibers (Array Method)D1445 Test Method for Breaking Strength and Elongationof Cotton Fibers (Flat Bundle Method)D1447
11、Test Method for Length and Length Uniformity ofCotton Fibers by Photoelectric MeasurementD1448 Test Method for Micronaire Reading of CottonFibersD7139 Terminology for Cotton Fibers3. Terminology3.1 For all terminology relating to D13.11, Cotton Fibers,refer to Terminology D7139.3.1.1 The following t
12、erms are relevant to this standard:calibration cotton standard, reference standard, working cottonstandard.3.2 For all other terminology related to textiles, refer toTerminology D123.4. Summary of Practice4.1 Testing instruments are adjusted in accordance withengineering principles to ensure that th
13、ey correspond properlyto the manufacturers calibration scales and instructions for theoperation of the instrument.4.2 Technicians are instructed to operate testings instru-ments in a consistent manner utilizing appropriate prescribedASTM methods.4.3 Specimens of the working cotton standard or calibr
14、ationcotton standard are tested before and periodically during theroutine testing of cotton samples using the same techniques forall specimens tested.1This practice is under the jurisdiction ofASTM Committee D13 on Textiles andis the direct responsibility of Subcommittee D13.11 on Cotton Fibers.Curr
15、ent edition approved July 1, 2012. Published August 2012. Originallyapproved in 1972. Last previous edition approved in 2007 as D302507. DOI:10.1520/D3025-07R12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book o
16、f 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.4.4 Observed values for samples tested are adjusted throughuse of a correction factor
17、 calculated from observed valuesobtained on reference standards to secure comparative level ofmeasurement.5. Significance and Use5.1 The purpose of this practice is to provide guidingprinciples for the use of reference standard cottons for thestandardization of instruments and techniques to obtain r
18、epro-ducible test results (within statistical limits) when the tests areperformed on samples of cotton fibers by the same or differentoperators at the same or different times, both within the samelaboratory and in different laboratories.5.2 Results obtained on cotton fiber tests on the samesample ma
19、y vary widely due to differences in instruments andoperator techniques. Some variation in test result levels can becontrolled by the physical adjustment of instruments in accor-dance with manufacturers instruction. Instrument adjustmentsare made only to cause instrument values to coincide withspecif
20、ied calibration points established by the manufacturer.Other variations in cotton fiber test results are caused bydifferences in technique used in specimen preparation, errors inreading test values from scales, variation in the referencestandard, and sampling errors in specimen selection. It isneces
21、sary that the mean value of at least four sets of determi-nations per operator-instrument be used in order to form asound basis for any adjustment of technique or for the use ofcorrection factors.35.3 In comparing results of different operators and differentlaboratories, for example, between the pur
22、chaser and the seller,it is essential that all results be obtained on replicate speci-mens. Values obtained on individual samples, as well as on areference standard are never absolute, but have a normalvariation about their mean due to heterogeneity of the sample.Therefore confidence limits of a tes
23、t value are dependent uponthe within laboratory variance for the test and the samplingerror. The level of the results in different laboratories will becomparable only to the extent of the use of the same referencestandards in both laboratories.5.4 Any one set of determinations on a reference standar
24、dmay be within the statistical limits of this reference standardcotton approximately 67 % of the time. The mean of aminimum of four sets of tests, as set out in the specific testprocedure, is required to establish a reliable mean value for thedetermination of the test level. Caution should be exerci
25、sed inthe adjustment of instrument or technique on the basis ofpreliminary results on the working cotton standard or calibra-tion cotton standard because of the variation within thesereference standards.5.5 When the mean value of the initial test results on areference standard cotton falls within on
26、e unit standard devia-tion of the established values, testing may be started onsamples of cotton fiber to be tested. If the mean value does notfall within two standard deviation units, recheck the instrumentadjustments and test an additional set of test specimens fromthe reference standard cotton. T
27、he mean value of these two setsof determinations, where instrument checks have shown theadjustments (instruments) to be in order, may then be used asa basis for modification of technique, or if correction factorsare to be used, the basis for the initiation of testing of unknownsamples. Correction fa
28、ctors should be based on determinationsmade before, during, and at the completion of routine testing.6. Reference Samples6.1 Calibration Cotton Standards:6.1.1 Calibration cotton standards are furnished with astatement of the mean values for one or more physicalcharacteristics, along with the precis
29、ion of the quoted meanvalue.4Such standards should be used only for those physicalcharacteristics for which mean values have been furnished.6.2 Working Cotton Standards:6.2.1 Using working cotton standards conserves the supplyof the more expensive calibration cotton standards. Well beforethe supply
30、of a working cotton standard has been depleted, anew working cotton standard should be prepared. It is goodlaboratory practice to run the old and new working cottonstandards in parallel for a period of time sufficient to ensurethat no changes in test result levels will occur at the time ofchanging t
31、o the new supply of working cotton standard.6.2.2 Working cotton standards would be so well blendedthat there is a minimum variation in the property of interest.Blending should be completed before determining the acceptedvalue for the property of interest.6.2.3 The accepted value of a physical chara
32、cteristic of aworking cotton standard should be based on extensive com-parisons with a calibration cotton standard having a reportedmean value for that physical characteristic. The comparisonsshould be made (1) on the specific instruments with which theworking cotton standard is to be used, (2) by t
33、he specificoperators who will be using those instruments, and (3) with thespecific test procedure to which the working cotton standard isto be applied.7. Adjustments of Instruments7.1 Verify the calibration or adjustment of a specific instru-ment in accordance with the instructions of the manufactur
34、er.Check the physical condition and adjustment of the instrumentat least twice daily, at the beginning and at the middle of thetest period, or more frequently if specified by the manufacturer.NOTE 3If experience indicates a need for more frequent checks,perform the checks as indicated.7.2 If instrum
35、ent malfunctions should occur, discontinuetesting until the cause of such malfunction has been corrected.NOTE 4Data from periodically tested calibration samples will indi-cate instrument difficulties and the need for repeating sample measure-ments.8. General Procedure8.1 Prepare four test specimens
36、taken from either of thereference standards (Section 6) and test them as directed in the3Worley, S., Jr. and Krowicki, R. S. Quality Control in Fiber Testing, Proceed-ings, 1968 Cotton Research Clinic. Textile Bulletin, April 1968, pp 3235.4Calibration cotton standards are available from the USDA, A
37、MS, CottonProgram, 3275 Appling Road, Memphis, TN 38133.D3025 07 (2012)2appropriate ASTM method. It is important that the instrumentbe operated in a consistent manner and that the level of resultsis within the limits established for the particular operator andinstrument (Note 5). Where results are n
38、ot within acceptablelimits, recheck instrument adjustments and test an additionalset of specimens of a reference standard. If after making anynecessary adjustments to the instruments in use, the observedtest results are still outside the prescribed limits, check theoperators technique carefully and
39、make any indicated adjust-ments or consider using a correction factor, if no adjustmentsare indicated.NOTE 5Operator limits are established by the operators mean andstandard deviation of test results obtained on the particular standard. Thesetest results may be from testing standards only, or may be
40、 cumulativestatistics over a period of time for the particular operator. In either case themean and standard deviation should be based on at least 100 sets ofdeterminations.8.1.1 If adjustment is made in the instrument, or operatortechnique is changed to obtain a different level of results, testaddi
41、tional specimens of a reference cotton sample to determinethat the mean of the additional observations fall within theprescribed limits before testing any unknown samples.9. Procedure for the Calculation and Use of CorrectionFactors9.1 Test and record the pertinent values for each property onat leas
42、t two test specimens of a reference standard cotton at thebeginning and at intervals during the test period. Make aminimum of four complete tests to obtain results to be used tocalculate a reliable correction factor. Make similar tests onspecimens from the routine samples.9.2 Calculate the mean of t
43、he observed values for thespecimens from the reference standard cotton and calculate thecorrection factor using Eq 1:F 5 S/V (1)where:F = the correction factor calculated to three decimal places,S = the established mean value for the reference standardcotton, andV = the observed mean value of all te
44、sts performed by oneoperatorinstrument on the reference standard cottonduring the test period.9.3 Calculate the corrected or adjusted value for a specifictest result using Eq 2:A 5 O 3 F (2)where:A = adjustedvalue,O = observed values for specimens tested, andF = correction factor calculated in 9.2.1
45、0. Keywords10.1 calibration cotton; cottonASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and t
46、he riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision
47、of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shoul
48、dmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D3025 07 (2012)3
