BS EN 12751-1999 Textiles - Sampling of fibres yarns and fabrics for testing《纺织品 试验用纤维、纱和织物的取样》.pdf

1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN 12751:1999 The Euro

2、pean Standard EN 12751:1999 has the status of a British Standard ICS 59.060.01; 59.080.20; 59.080.30 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Textiles Sampling of fibres, yarns and fabrics for testingThis British Standard, having been prepared under the direction of the

3、 Sector Committee for Materials and Chemicals, was published under the authority of the Standards Committee and comes into effect on 15 November 1999 BSI 11-1999 ISBN 0 580 35236 6 BS EN 12751:1999 Amendments issued since publication Amd. No. Date Comments National foreword This British Standard is

4、the English language version of EN 12751:1999. It supersedes BS 2545:1965 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee TCI/24, Physical testing of textiles, which has the responsibility to: aid enquirers to understand the text; present to the respo

5、nsible European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its s

6、ecretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Stand

7、ards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pag

8、es This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 20, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued.(8523($167$1$5 (1 1250(8523e(11( (8523b,6&+(1250 -XO ,&6 (QJOLVKYH

9、UVLRQ 7HWLOHV6DPSOLQJRIILEUHVDUQVDQGIDEULFVIRUWHVWLQJ 7HWLOHV(FKDQWLOORQDJHGHVILEUHVGHVILOVHWGHVpWRIIHV HQYXHGHVHVVDLV 7HWLOLHQ3UREHQDKPHQYRQ)DVHUQ*DUQHQXQGWHWLOHQ )OlFKHQJHELOGHQIU3UIXQJHQ 7KLV(XURSHDQ6WDQGDUGZDVDSSURYHGE&(1RQ-XQH &(1PHPEHUVDUHERXQGWRFRPSOZLWKWKH&(1&(1(/(&,QWHUQDO5HJXODWLRQVZKLFKVW

10、LSXODWHWKHFRQGLWLRQVIRUJLYLQJWKLV(XURSH DQ 6WDQGDUGWKHVWDWXVRIDQDWLRQDOVWDQGDUGZLWKRXWDQDOWHUDWLRQ8SWRGDWHOLVWVDQGELEOLRJUDSKLFDOUHIHUHQFHVFRQFHUQLQJV XFKQDWLRQDO VWDQGDUGVPDEHREWDLQHGRQDSSOLFDWLRQWRWKH&HQWUDO6HFUHWDULDWRUWRDQ&(1PHPEHU 7KLV(XURSHDQ6WDQGDUGHLVWVLQWKUHHRIILFLDOYHUVLRQV(QJOLVK)UHQFK*HU

11、PDQ$YHUVLRQLQDQRWKHUODQJXDJHPDGHEWUD QVODWLRQ XQGHUWKHUHVSRQVLELOLWRID&(1PHPEHULQWRLWVRZQODQJXDJHDQGQRWLILHGWRWKH&HQWUDO6HFUHWDULDWKDVWKHVDPHVWDWXVDVW KHRIILFLDO YHUVLRQV &(1PHPEHUVDUHWKHQDWLRQDOVWDQGDUGVERGLHVRI$XVWULD%HOJLXP&HFK5HSXEOLFHQPDUN)LQODQG)UDQFH*HUPDQ*UHHFH ,FHODQG,UHODQG,WDO/XHPERXUJ1HW

12、KHUODQGV1RUZD3RUWXJDO6SDLQ6ZHGHQ6ZLWHUODQGDQG8QLWHG.LQJGRP (8523($1&200,77()2567$1$5,=$7,21 &20,7e(8523e(1(1250$/,6$7,21 (8523b,6&+(6.20,7()h5125081* &HQWUDO6HFUHWDULDWUXHGH6WDVVDUW%UXVVHOV &(1 $OOULJKWVRIHSORLWDWLRQLQDQIRUPDQGEDQPHDQVUHVHUYHG ZRUOGZLGHIRU&(1QDWLRQDO0HPEHUV 5HI1R(1(3DJH (1 %6, )RUHZ

13、RUG 7KLV(XURSHDQ6WDQGDUGKDVEHHQSUHSDUHGE7HFKQLFDO&RPPLWWHH&(17&7HWLOHVDQGWHWLOHSURGXFWV WKHVHFUHWDULDWRIZKLFKLVKHOGE%6, 7KLV(XURSHDQ6WDQGDUGVKDOOEHJLYHQWKHVWDWXVRIDQDWLRQDOVWDQGDUGHLWKHUESXEOLFDWLRQRIDQLGHQWLFDOWHWRU EHQGRUVHPHQWDWWKHODWHVWE-DQXDUDQGFRQIOLFWLQJQDWLRQDOVWDQGDUGVVKDOOEHZLWKGUDZQDWWKHO

14、DWHVW E-DQXDU ,WLVUHODWHGWR,627HWLOHILEUHV6RPHPHWKRGVRIVDPSOLQJIRUWHVWLQJ $FFRUGLQJWRWKH&(1&(1(/(&,QWHUQDO5HJXODWLRQVWKHQDWLRQDOVWDQGDUGVRUJDQLDWLRQVRIWKHIROORZLQJ FRXQWULHVDUHERXQGWRLPSOHPHQWWKLV(XURSHDQ6WDQGDUG$XVWULD%HOJLXP&HFK5HSXEOLFHQPDUN)LQODQG )UDQFH*HUPDQ*UHHFH,FHODQG,UHODQG,WDO/XHPERXUJ1HW

15、KHUODQGV1RUZD3RUWXJDO6SDLQ6ZHGHQ 6ZLWHUODQGDQGWKH8QLWHG.LQJGRP ,QWURGXFWLRQ 1RVLQJOHWHFKQLTXHRIVDPSOLQJFDQEHGHYLVHGWKDWZLOOVHUYHLQDOOFLUFXPVWDQFHV6DPSOLQJIURPDEDOHRI FRWWRQIRUHDPSOHSUHVHQWVSUREOHPVTXLWHGLIIHUHQWIURPWKRVHHQFRXQWHUHGLQVDPSOLQJIURPDFRQVLJQPHQWRI DUQSDFNDJHVZKLOHVDPSOLQJIURPDFDUGZHELVDJ

16、DLQGLIIHUHQWIURPHLWKHU 7KHVDPSOHVDUHJHQHUDOOWDNHQDVWKHVKLSSLQJXQLWVPDNLQJXSDORWVXFKDVEDOHVRIILEUHFDVHVRIDUQUROOV RIIDEULFRUFDUWRQVRIJDUPHQWVRURWKHUILQLVKHGSURGXFWV$GHTXDWHVDPSOLQJIRUDFFHSWDQFHWHVWLQJUHTXLUHV WDNLQJLQWRDFFRXQWQRWRQOWKHYDULDELOLWEHWZHHQWKHODERUDWRUVDPSOHVEXWDOVRWKHYDULDELOLWEHWZHHQWKH

17、 ODERUDWRUWHVWVDPSOHVDQGEHWZHHQWKHWHVWVSHFLPHQV 7KHREMHFWLYHRIVDPSOLQJPDYDUZLWKWKHSXUSRVHIRUZKLFKWKHWHVWPHWKRGLVXVHG7KHREMHFWLYHRIVDPSOLQJ IRUDFFHSWDQFHWHVWLQJLVWRREWDLQPDWHULDOZKLFKZLOOHVWLPDWHZLWKRXWELDVDSURSHUWRIWKHORWEHLQJHYDOXDWHG DQGZKLFKDOORZVPDNLQJDGHFLVLRQRQZKHWKHUWRDFFHSWRUUHMHFWDORWZLWKUH

18、DVRQDEOHSURGXFHUVDQGFRQVXPHUV ULVNVZKHQWKHDFFHSWDEOHTXDOLWOHYHODQGWKHOLPLWLQJTXDOLWOHYHODUHDWUHDOLVWLFOHYHOV7KHUHDUHQRUPDOOPDQ ZDVWRHVWLPDWHWKHSURSHUWRILQWHUHVWWRDVSHFLILHGGHJUHHRISUHFLVLRQ7KHPRVWHFRQRPLFDOZDWRGRVRZLOO GHSHQGRQWKHUHODWLYHVLHRIWKHVRXUFHVRIYDULDELOLWDVVRFLDWHGZLWKVDPSOLQJWKHODERUDWRUV

19、DPSOHV $VHOHFWLRQRIPHWKRGVLVWKHUHIRUHSUHVHQWHGLOOXVWUDWLQJWHFKQLTXHVWKDWKDYHEHHQIRXQGDFFHSWDEOHLQPHHWLQJ WKHFRPPRQHUWSHVRISUREOHPHQFRXQWHUHGLQVDPSOLQJIRUWKHDVVHVVPHQWRIILEUHDUQRUIDEULFTXDOLW 0HWKRGVSHFXOLDUWRWKHUHTXLUHPHQWVRIUHVHDUFKDUHQRWLQFOXGHGQRUDUHVXFKVSHFLDOWHFKQLTXHVDVKDYHWREH XVHGIRUHDPSOHLQ

20、VDPSOLQJRIZRROIURPWKHIOHHFHRUFRWWRQIURPWKHVHHG3DJH (1 %6, 6FRSH 7KLV(XURSHDQ6WDQGDUGVSHFLILHVVHYHUDOPHWKRGVIRUSUHSDULQJODERUDWRUVDPSOHVRIILEUHVDUQVRUIDEULFVDQG SUHVHQWVDOLPLWHGWUHDWPHQWRIWKHSUREOHPRIGUDZLQJVSHFLPHQVIRUWHVWLQJ 7KHSULQFLSOHRIHDFKPHWKRGLVJLYHQDWWKHEHJLQQLQJRIWKHFODXVHGHDOLQJZLWKWKHPHWK

21、RG ,WLVQRWSRVVLEOHIRUWKHFRYHUDJHRIHDFKLQGLYLGXDOSURFHGXUHWREHIXOOFRPSUHKHQVLYHLQPDQLQVWDQFHVWKH VHOHFWLRQRIWHVWVDPSOHVRUWHVWVSHFLPHQVLVQHFHVVDULOFRYHUHGEWKHDSSURSULDWHPHWKRGRIWHVW 7KHVHOHFWLRQRIOHQJWKELDVHGVDPSOHVLVQRWZLWKLQWKHVFRSHRIWKLVVWDQGDUGQRUDUHSDUWLFXODUSURFHGXUHVIRU GHWHUPLQDWLRQRIFRPPHUFLD

22、OZHLJKWVRUPRLVWXUHFRQWHQW $QQH$DQGWKHWDEOHVDUHJLYHQLQWKLVVWDQGDUGIRUJHQHUDOJXLGDQFHLQGHWHUPLQLQJWKHVLHRIWKHWHVWVDPSOH WREHWDNHQLQRUGHUWKDWWKHGHWHUPLQHGVDPSOHPHDQKDVJLYHQFRQILGHQFHOLPLWV HILQLWLRQV )RUWKHSXUSRVHVRIWKLVVWDQGDUGWKHIROORZLQJGHILQLWLRQVDSSO ODERUDWRUVDPSOH 6DPSOHLQWHQGHGWREHUHSUHVHQWDWLY

23、HRIDODUJHEXONRIPDWHULDOLQWKHVWDWHLQZKLFKLWLV VHQWWRWKHODERUDWRU$FRQYHQLHQWVLHRIVDPSOHIRUPDQWSHVRIWHVWLQYROYLQJRQOVPDOOWHVWVSHFLPHQVLV DERXWJWRJDODUJHUDPRXQWZLOOEHUHTXLUHGIRUWHVWVLQYROYLQJUHODWLYHOODUJHWHVWVSHFLPHQV ODERUDWRUWHVWVDPSOH 7KDWSRUWLRQRIILEUHVDUQRUIDEULFVWDNHQIURPWKHODERUDWRUVDPSOHLQVXFKD

24、ZD DVWRHQVXUHLWVUHSUHVHQWDWLYHFKDUDFWHUDQGWRSURYLGHDTXDQWLWVPDOOHQRXJKWREHHDVLOFRQYHUWLEOHLQWRWHVW VSHFLPHQV WHVWVSHFLPHQ 7KDWSDUWRIWKHODERUDWRUVDPSOHDUQVILEUHVIDEULFVHWFZKLFKLVWHVWHGDWRQHWLPH QXPHULFDOVDPSOH 6DPSOHLQZKLFKDOOLQGLYLGXDOVILEUHVDUQVRUIDEULFVLQWKHSRSXODWLRQKDYHDQHTXDO FKDQFHRIEHLQJUHSUH

25、VHQWHG OHQJWKELDVHGVDPSOH 6DPSOHLQZKLFKWKHFKDQFHRIDQILEUHRIWKHSRSXODWLRQEHLQJUHSUHVHQWHGLV SURSRUWLRQDOWRWKHOHQJWKRIWKDWILEUH LQGLYLGXDO $QVLQJOHVSHFLPHQRIILEUHRUDUQRUIDEULFWKDWFRXOGEHWDNHQIRUWKHSXUSRVHRIPHDVXUHPHQW SRSXODWLRQ 7KHDJJUHJUDWHRILQGLYLGXDOVWKDWLWLVGHVLUHGWRFKDUDFWHULHLQRQHRUPRUHSDUWLFXO

26、DUVIRU HDPSOHILEUHVFRQWDLQHGLQDEDOHRIFRWWRQDOOWKHFRQVWLWXHQWILEUHVLQDVHWRIDUQFRSV RQLQJ :KHQWKHSRSXODWLRQWREHVDPSOHGLVNQRZQWRYDUIURPSDUWWRSDUWZLWKUHVSHFWWRWKHSURSHUWWR EHLQYHVWLJDWHGWKHLQGLYLGXDOVRUJURXSVRILQGLYLGXDOVLQWKHSRSXODWLRQDUHWDNHQDWUDQGRPIURPZLWKLQWKH GLIIHUHQWSDUWVRURQHVFKRVHQVRWKDWDOOYDU

27、LDWLRQVRIWKHSURSHUWDUHUHSUHVHQWHGLQGXHSURSRUWLRQ7KLV RSHUDWLRQLVNQRZQDVRQLQJ 6DPSOLQJRIILEUHV 6DPSOLQJPHWKRGVIRUFRWWRQILEUHV *HQHUDO 7KLVFODXVHJLYHVPHWKRGVIRUWKHSUHSDUDWLRQRIQXPHULFDOODERUDWRUVDPSOHV 7KHPHWKRGVGHVFULEHGLQWRDUHDSSOLFDEOHWREXONVRIFRWWRQILEUHVLQYDULRXVIRUPV3DJH (1 %6, 6DPSOLQJIURPDVPDO

28、OEXONRIUDZRUEOHQGHGFRWWRQ ,IWKHEXONFRQVLVWVRIOHVVWKDQNJRIORRVHUDZFRWWRQVSUHDGLWRXWLQDQHYHQODHU8QOHVVRWKHUZLVHVWDWHG REWDLQWKHODERUDWRUVDPSOHEVHOHFWLQJDWUDQGRPDPLQLPXPRIWXIWVHDFKRIJWRJ ,IWKHEXONLVJUHDWHUWKDQNJGLYLGHLWLQWRDQXPEHURIHTXDOSRUWLRQVDQGWDNHDQHTXDOQXPEHURIWXIWVRI JWRJHDFKIURPHDFKSRUWLRQVXFKW

29、KDWWKHWRWDOQXPEHUIURPDOOSRUWLRQVHFHHGV 6DPSOLQJIURPDEXONFRQVLVWLQJRIDEDOHRIFRWWRQ *HQHUDO 7KHUHLVYDULDWLRQLQPRVWILEUHSURSHUWLHVEHWZHHQDQGZLWKLQODHUVRIWKHVDPHEDOHRIFRWWRQ7KHYDOXHVRI FRHIILFLHQWVRIZLWKLQDQGEHWZHHQODHUYDULDWLRQDQGRIWKHUDWLRRIWKHVHFRHIILFLHQWVRIYDULDWLRQYDUDFFRUGLQJ WRWKHILEUHFKDUDFWHUL

30、VWLFVXQGHUFRQVLGHUDWLRQDQGDOVRZLWKWKHWSHRIFRWWRQ 3URFHGXUH ,IWKHEDOHLVRSHQDVXLWDEOHODERUDWRUVDPSOHPDEHREWDLQHGEVHOHFWLQJWXIWVDWUDQGRPWKURXJKRXWHDFK RIHTXDOOVSDFHGODHUV ,IWKHEDOHKDVQRWEHHQRSHQHGWKHDERYHSURFHGXUHFDQQRWEHIROORZHG,QWKLVFDVHWKHIROORZLQJSURFHGXUH PDEHIHDVLEOH (WUDFWWKHUHTXLUHGQXPEHURIWXIW

31、VEUHPRYLQJFRWWRQIURPRQHRUPRUHRIWKHHGJHVWKDWDUHSHUSHQGLFXODUWR WKHODHUVLQWKHEDOHVRWKDWWKHVDPSOHLQFOXGHVPDWHULDOIURPPDQODHUV,QWDNLQJWKHWXIWVUHMHFWDQVRLOHG FRWWRQIURPWKHRXWVLGHRIWKHEDOHWKHSURFHGXUHPDEHIDFLOLWDWHGEFXWWLQJRQHRIWKHHQGEDQGVURXQGWKH EDOH 127($OHVVVDWLVIDFWRUVDPSOHLVLHOGHGEVHOHFWLQJWXIWVIURP

32、YDULRXVSODFHVRYHUWKHXSSHUDQGORZHU VLGHVRIDEDOH $OWKRXJKWKLVFRWWRQLVHDVLODFFHVVLEOHDQODERUDWRUVDPSOHREWDLQHGLQWKLVPDQQHUZLOOUHSUHVHQWDWWKHPRVW WZRODHUVRQHRQHDFKVLGHRIWKHEDOH 6DPSOLQJIURPDEXONFRQVLVWLQJRIVHYHUDOEDOHVRIFRWWRQ *HQHUDO 7KHGHWDLOHGPHWKRGRIVDPSOLQJGHSHQGVRQWKHWSHRIWHVWWREHFDUULHGRXWWKHQXPE

33、HURIEDOHVDQGWKHOLNHO YDULDWLRQEHWZHHQWKHEDOHV 3URFHGXUH 7KHIROORZLQJSURFHGXUHVKDOOEHXVHGXQOHVVWKHVSHFLILFDWLRQVWDWHVRWKHUZLVH :KHQWKHQXPEHURIEDOHVLVJUHDWHUWKDQDQGWKHUHDOYDULDWLRQLQWKHEXONLVQRWDSSUHFLDEOJUHDWHU WKDQWKHSUHFLVLRQUHTXLUHGLQWKHWHVWUHVXOWPDNHDUDQGRPFKRLFHRIRIWKHEDOHVRUEDOHVLIRIWKH EXONLVO

34、HVVWKDQEDOHVWKHQIURPWKHVHOHFWHGEDOHVWDNHDPLQLPXPRIWXIWVWDNLQJDQHTXDOQXPEHURI WXIWVIURPHDFKODHURIHDFKEDOH 6DPSOLQJZLWKRXWRSHQLQJEDOHV )RUPRVWFRPPHUFLDOSXUSRVHVZKHQVHOHFWLQJDVDPSOHIURPDEDOHRIFRWWRQLWLVLPSUDFWLFDEOHWRREWDLQD UHSUHVHQWDWLYHVDPSOHERSHQLQJDEDOHDQGIROORZLQJWKHSURFHGXUHGHVFULEHGLQDERYH6DPSO

35、HVSUHSDUHG EVHOHFWLQJFRWWRQIURPRQHRUWZRODHUVLQDEDOHDUHDFFHSWDEOHIRUPDQSXUSRVHVIRUTXDOLWFODVVLILFDWLRQDQG IRUVRPHIRUPVRIWHVWLQJIRUHDPSOHGHWHUPLQDWLRQRIPLFURQDLUHYDOXHZKHQSDVWHSHULHQFHLQGLFDWHVWKDWWKH3DJH (1 %6, IHDWXUHXQGHUFRQVLGHUDWLRQYDULHVDSSUHFLDEOPRUHIURPEDOHWREDOHLQDFRPPHUFLDOORWWKDQEHWZHHQODHU

36、VLQ WKHVDPHEDOH8QGHUVXFKFLUFXPVWDQFHVLWLVUHFRPPHQGHGWKDWDVDPSOHEHSUHSDUHGLQWKHIRUPRIWZRFOXPSV RIFRWWRQVLPLODULQVXUIDFHDUHDDQGPDVVWDNHQIURPRSSRVLWHRXWHUODHUVRIWKHEDOHDQGZLWKWKHGLVWDQFHWR WKHHGJHVRIWKHEDOHDPLQLPXPRIPP7KHIDFHRIWKHVDPSOHVKDOOEHQRWOHVVWKDQPP PPDQG WKHWRWDOPDVVQRWOHVVWKDQJ$VDPSOHFRQVLVWLQ

37、JRIDFOXPSRIWKHVDPHVXUIDFHDUHDDQGWRWDOPDVVFXW IURPRQHRXWHUODHURQOLVOHVVUHSUHVHQWDWLYHDQGIXOILOVWKHUHTXLUHPHQWVRIWKLV6WDQGDUGRQOLIPXWXDOO DJUHHGEWKHSDUWLHVFRQFHUQHG 3UHSDUDWLRQRIODERUDWRUWHVWVDPSOHV *HQHUDO ,QFHUWDLQFDVHVLWPDEHQHFHVVDUWRKDYHDODERUDWRUWHVWVDPSOHSUHSDUHGIURPWKHODERUDWRUVDPSOH 7KHVHODERU

38、DWRUWHVWVDPSOHVVKDOOEHSUHSDUHGEDPHWKRGZKLFKWDNHVLQWRFRQVLGHUDWLRQWKHWHVWWREH SHUIRUPHGDQGWKHGHJUHHRIDFFXUDFGHVLUHG ,QJHQHUDOILEUHEOHQGLQJEDPHFKDQLFDOEOHQGHULVSUHIHUDEOHSDUWLFXODUOZKHQWKHWHVWVSHFLPHQLVVPDOOLQ VLHDVLVWKHFDVHLQWKHIODWEXQGOHVWUHQJWKWHVW+RZHYHULQVRPHFDVHVVDPSOHVSUHSDUHGEKDQGDUH DGHTXDWH

39、:KHQWKHODERUDWRUVDPSOHFRQVLVWVRIWXIWVWDNHQEFXWWLQJLQWRWKHEDOHVFXWILEUHVVKDOOQRWEHLQFOXGHGLQWKH ODERUDWRUWHVWVDPSOH 0HFKDQLFDOEOHQGLQJSUHIHUUHGPHWKRG 7KHPHFKDQLFDOEOHQGHULVGHVLJQHGWRXVHDFHUWDLQPDVVRIILEUHVIRUHDPSOHXSWRJ 6SUHDGRXWWKHODERUDWRUVDPSOHVRWKDWSLQFKHVFDQEHWDNHQIURPLWDWDQSRLQW7DNHVPDOOSLQFKHV

40、RIILEUH IURPDWOHDVWGLIIHUHQWHYHQOVSDFHGSRLQWVLQWKHODERUDWRUVDPSOH 3HUIRUPDOLJKWGUDIWLQJDFWLRQRQWKHSLQFKHVEHIRUHIHHGLQJWKHPLQWRWKHPHFKDQLFDOEOHQGHUVRDVWRIRUPDV XQLIRUPDVKHHWRIILEUHDVSRVVLEOH%OHQGWKHILEUHVXVLQJWKHEOHQGHUVRDVWRSURGXFHDSUDFWLFDOO KRPRJHQHRXVVDPSOHWDNLQJFDUHQRWWRGDPDJHWKHILEUHV 0DQXDOPHWKRGV LIIHUHQWPHWKRGVKDYHEHHQGHVLJQHGIRUGLIIHUHQWPHWKRGVRIWHVWIRUHDPSOHFXWVTXDULQJPDNLQJKDQG VOLYHUVDQGPDNLQJVPDOOVDPSOHVIRUVXFFHVVLYHKDOYLQJDQGFRPELQLQJ,QVRPHFDVHVLWLVSUHIHUDEOHWRSUHSDUH WHVWVSHFLPHQVGLUHFWOIURPWKHODERUDWRUVDPSOH 6DPSOLQJPHWKRGIRUPDQPDGHVWDSOHILEUHV *HQHUDO 7KLV