1、Designation: D 3025 07Standard Practice forStandardizing Cotton Fiber Test Results by Use ofCalibration Cotton Standards1This standard is issued under the fixed designation D 3025; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, th
2、e year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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 instruments and techni
3、quesused 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 adjust an operators
4、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 cellophane sheets, i
5、n 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 a means for sta
6、ndardizingtechniques 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 cotton fibers in a
7、ny 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 testing cotton fibers
8、. 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: Test Methods
9、D 1440, D 1445,D 1447, and D 1448.1.6 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 of regulat
10、ory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 123 Terminology Relating to TextilesD 1440 Test Method for Length and Length Distribution ofCotton Fibers (Array Method)D 1445 Test Method for Breaking Strength and Elongationof Cotton Fibers (Flat Bundle Method)D 1447 Test Me
11、thod for Length and Length Uniformity ofCotton Fibers by Fibrograph MeasurementD 1448 Test Method for Micronaire Reading of CottonFibersD 7139 Terminology for Cotton Fibers3. Terminology3.1 For all terminology relating to D13.11, Cotton Fibers,refer to Terminology D 7139.3.1.1 The following terms ar
12、e relevant to this standard:calibration cotton standard, reference standard, working cottonstandard.3.2 For all other terminology related to textiles, refer toTerminology D 123.4. Summary of Practice4.1 Testing instruments are adjusted in accordance withengineering principles to ensure that they cor
13、respond properlyto the manufacturers calibration scales and instructions for theoperation of the instrument.1This practice is under the jurisdiction ofASTM Committee D13 on Textiles andis the direct responsibility of Subcommittee D13.11 on Cotton Fibers.Current edition approved Jan. 1, 2007. Publish
14、ed January 2007. Originallyapproved in 1972. Last previous edition approved in 2001 as D 302501.2For 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 Docume
15、nt Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.2 Technicians are instructed to operate testings instru-ments in a consistent manner utilizing appropriate prescribedASTM methods.4.3 Specimens of t
16、he working cotton standard or calibrationcotton standard are tested before and periodically during theroutine testing of cotton samples using the same techniques forall specimens tested.4.4 Observed values for samples tested are adjusted throughuse of a correction factor calculated from observed val
17、uesobtained 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 repro-ducible test results (wi
18、thin 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 may vary widely due to differen
19、ces 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 withspecified calibration points establ
20、ished 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 isnecessary that the mean value of a
21、t 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 purchaser and the seller,it is e
22、ssential 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 test value are dependent uponthe
23、 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 standardmay be within the statistica
24、l 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 exercised inthe adjustment of instr
25、ument 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 one unit standard devia-tion of
26、 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. The mean value of these two se
27、tsof 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 factors should be based on dete
28、rminationsmade 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 precision of the quoted meanvalue.4
29、Such 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 of a working cotton standard
30、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 to the new supply of working c
31、otton 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 characteristic of aworking cotton
32、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 the specificoperators who will
33、 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 manufacturer.Check the physical conditi
34、on 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.3Worley, S., Jr. and Krowicki, R. S. Qualit
35、y Control in Fiber Testing, Proceed-ings, 1968 Cotton Research Clinic. Textile Bulletin, April 1968, pp 3235.4Calibration cotton standards are available from the USDA, AMS, CottonProgram, 3275 Appling Road, Memphis, TN 38133.D30250727.2 If instrument malfunctions should occur, discontinuetesting unt
36、il 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 taken from either of thereference standards (Section
37、6) and test them as directed in theappropriate 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 not within acceptablelimits, recheck i
38、nstrument 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 make any indicated adjust-ments or co
39、nsider 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 cumulativestatistics over a period o
40、f 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, testadditional specimens of a reference cotto
41、n 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 least two test specimens of a reference s
42、tandard 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 the observed values for thespecimens f
43、rom 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 tests performed by oneoperatorinstrumen
44、t 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 9.2.10. Keywords10.1 calibration cotton; c
45、ottonASTM 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 the riskof infringement of such rights
46、, 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 of this standard or for additional st
47、andardsand 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 shouldmake your views known to the ASTM Co
48、mmittee 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).D3025073
