1、Designation:D252522Standard Practice forSampling Wool for Moisture1This standard is issued under the fixed designation D2525;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates
2、the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice covers the design of a sampling plan to beused to obtain samples for the determination of the moisturecontent of grease wool,scoured wool,carded wool,garnett
3、edwool,wool top and intermediate products,and rovings.1.2 Directions are given for the designation of samplingunits,calculation of the number of sampling units required toachieve a preselected precision and confidence level or,alternatively,for calculating the confidence limits for the meanbased on
4、the variability of the sample tested.NOTE1This practice for devising a sampling plan is intended for usein connection with Test Method D1576 or Test Method D2462.Thesampling of raw wool for the determination of clean wool fiber present iscovered in Practice D1060.1.3 This international standard was
5、developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Doc
6、uments2.1 ASTM Standards:2D123 Terminology Relating to TextilesD1060 Practice for Core Sampling of Raw Wool in Packagesfor Determination of Percentage of Clean Wool FiberPresentD1576 Test Method for Moisture in Wool by Oven-DryingD2462 Test Method for Moisture in Wool by DistillationWith Toluene(Wit
7、hdrawn 2022)3D4845 Terminology Relating to WoolE122 Practice for Calculating Sample Size to Estimate,WithSpecified Precision,the Average for a Characteristic of aLot or Process3.Terminology3.1 For all terminology related to D13.13,Wool and Felt,see Terminology D4845.3.1.1 The following terms are rel
8、evant to this standard:laboratory sample,lot lot sample,sample,sampling unit,specimen.3.2 For definitions of all other textile terms see TerminologyD123.4.Summary of Practice4.1 Directions are given for subdividing a lot of materialinto potential sampling units and for providing each potentialsampli
9、ng unit with its own unique identification.4.2 Directions are given for calculating the number of suchsampling units required to give a preselected allowable varia-tion at a stated probability level,or for calculating confidencelimits for the sample mean obtained for a given size of sample.4.3 Direc
10、tions are given for deciding which particular sam-pling units should be chosen to constitute the required lotsample.These directions ensure that all potential samplingunits have approximately the same chance of being selected forthe lot sample.5.Significance and Use5.1 This recommended practice furn
11、ishes directions for thesampling of wool of the various forms indicated in Section 1,in order that correct probability statements may be made aboutthe relationship between the sample mean and the populationmean.If these statements are to be correct,certain conditions,which are stated,must hold.5.2 T
12、his recommended practice requires that a deliberate actof randomization be performed so that all potential samplingunits have approximately the same chance of being taken andno sampling unit is deprived of its chance of being taken.5.3 In any case where insufficient information about thevariability
13、of the sampling units within the lot is available,directions are given for calculating confidence limits for thesample mean so that a correct probability statement can still bemade.1This practice is under the jurisdiction of the ASTM Committee D13 onTextilesand is the direct responsibility of Subcom
14、mittee D13.13 on Wool and Felt.Current edition approved June 1,2022.Published July 2022.Originally approvedin 1966.Last previous edition approved in 2013 as D2525 13 which waswithdrawn in January 2022 and reinstated in June 2022.DOI:10.1520/D2525-22.2For referenced ASTM standards,visit the ASTM webs
15、ite,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.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100
16、 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.16.Preliminary Conditions6.1 If it is desired to calculate a sample size to achieve apreselected precision at
