1、Designation: D 4204 06Standard Practice forPreparing Plastic Film Specimens for a Round-Robin Study1This standard is issued under the fixed designation D 4204; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisi
2、on. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This practice covers the preparation of test sets of plasticfilm specimens for subsequent use in an interlaboratory round-robin
3、 study to evaluate the precision of a test method.1.2 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 establish appro-priate safety and health practices and determine the applica-bility of r
4、egulatory limitations prior to use.NOTE 1There is no similar or equivalent ISO standard.2. Referenced Documents2.1 ASTM Standards:2E 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 f
5、ilm specimenone piece of a sample obtained bycutting across the width of the sample and to a length such thatone test specimen can subsequently be prepared.NOTE 2For any sample in a laboratory, the specified number of filmspecimens in a test unit (n1) are tested to produce a single test result in as
6、hort-time period, while replicate test results are obtained over a longertime period. Thus, there are within-laboratory components of variabilityfor both short-term and long-term testing. This practice calls thesewithin-day and between-day components of variability, inasmuch asround-robin protocols
7、often specify that replicate test results be obtainedon different days.3.1.2 samplea quantity of film of a width appropriate tothe test method under study and of a length sufficient to yieldthe total number of film specimens needed for the plannedround-robin study.3.1.3 test resultthe value (usually
8、, the arithmetic average)of the property derived from one test unit.3.1.4 test seta group of several film specimens, in anumber greater than that specified for a test unit.3.1.5 test specimenthe individual piece of film to betested, usually of specified dimensions, that is to be cut fromone film spe
9、cimen and tested, to produce one value of theproperty, or properties, by the test method under study.3.1.6 test unita specified number of film specimens fromwhich an equal number of test specimens is to be prepared andtested in a short-time span to yield one test result for eachproperty.3.2 Abbrevia
10、tions:RR = round-robin studyq = number of samples to be used in the RRr = total number of film assemblies that will be neededfor each lab to complete the necessary testingn1= specified number of film specimens in a test unitn2= number of additional film specimens in each test setp1= number of labora
11、tories participating in the RRp2= number of additional “latent” laboratories providedfor in the specimen preparation procedureL1= film-specimen length appropriate for preparing onetest specimenL2= total length of film necessary to produce samples froparticipating plus latent laboratories; L2=(p1+ p2
12、)(L1)SD = standard deviation for a single source of variabilityfor one given sampleS1= standard deviation for within-laboratory within-dayvariability of a test valueS2= standard deviation for within-laboratory variability ofa test resultS3= standard deviation for between-laboratory variabilityof a t
13、est resultS4= standard deviation for within-sample variabilitySr= standard deviation of a within-laboratory single testresult for one given sample on any daySR= standard deviation of a between-laboratory single testresult for one given sample on any day1This practice is under the jurisdiction ofASTM
14、 Committee D20 on Plastics andis the direct responsibility of Subcommittee D20.19 on Film and Sheeting.Current edition approved Sept. 1, 2006. Published September 2006. Originallyapproved in 1982. Last previous edition approved in 2000 as D 4204 - 00.2For referenced ASTM standards, visit the ASTM we
15、bsite, 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.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harb
16、or Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4. Significance and Use4.1 This practice is intended to assist task groups participat-ing in a round-robin study with the preparation of test sets offilm specimens from film samples in the form of rolls on a core.4.2 This practic
17、e assumes that the essential features of theround-robin protocol have already been established by follow-ing the guidance of Practice E 691. In particular, it is assumedthat the following are known: (1) the number of film samplesto be used, (2) the number of participating laboratories, (3) thenumber
18、 of replicate test results to be generated by eachlaboratory for each sample, and (4) the number of testspecimens required to yield one test result for each sample.4.3 In accordance with this practice, samples are partitionedinto test sets so that real within-sample variability will notunduly distor
19、t the conclusions drawn from statistical analysesof the data generated in the round-robin study.5. Sample Selection5.1 Select the number of samples q to be used in theround-robin (RR) study that would be expected to be uniformfor which the standard deviation for within-sample variability(S4) should
20、be small. The larger the value of standard deviationfor within-sample variability (S4), the greater will be theadverse effect upon conclusions drawn from round-robin dataregarding test method precision.5.1.1 For any sample, the total observed variability willalways contain the component of standard
21、deviation for within-sample variability (S4). In the typical study, sample standarddeviation for within-sample variability (S4) is not estimatedseparately; the result is an overestimation of one or more of thecomponents of variability: standard deviation for within-laboratory within-day variability
22、(S1), standard deviation forwithin-laboratory between-day variability, (S2), standard devia-tion for between-laboratory variability (S3) that the study isdesigned to estimate. Because of this, standard deviation forwithin-sample variability (S4) is a nuisance factor to be dealtwith as conveniently a
23、s possible.5.1.2 It is preferable to confound standard deviation forwithin-sample variability (S4) with the within-laboratory com-ponents of variability, of within-day and between-day compo-nents of variability (S1and S2), and to obtain an estimate ofbetween-laboratory variability (S3) that is not i
24、nflated bywithin-sample variability (S4). This practice is intended toaccomplish this. In most cases, in accordance with thispractice, the standard deviation for within-sample variability(S4) is confounded only with within-laboratory within-dayvariability (S1), so that the estimate of within-laborat
25、orybetween-day variability (S2) is also not inflated by the standarddeviation for within-sample variability, (S4). The confoundingof standard deviation for within-sample variability (S4) withonly within-laboratory within-day variability (S1) is equivalentto a completely random selection of all film
26、specimens fromthe film sample.5.1.3 The best source of samples is from commercial orlaboratory extrusion operations that have demonstrated thecapability to produce film under conditions that have shownthat appreciable systematic trends in the level of the property,or properties, to be measured did n
27、ot occur as the sample wasbeing fabricated.5.2 Before preparing test sets as described in Section 6, haveone laboratory test the specified number of test samples (n1)from each sample. If the range of property levels thus found isnarrower than is deemed appropriate for the study, it may bedesirable t
28、o obtain one or more additional samples, to replaceone or more of the number of samples to be used in the RR (q)collected initially.6. Procedure6.1 Determine the number of extra film specimens to beused for each test (n2) for the RR. In view of the way test setsare made up, as described subsequently
29、, there will always betwo “sacrifice” film specimens in a test set, one on top and oneon bottom of the stack, that serve to protect the integrity of thefilm specimens in between. These two are not to be used;always take test specimens from film specimens between thetop and bottom film specimens in t
30、he test set. In addition, it isusually advisable to include a minimum of one or two extrafilm specimens in each test set, in the event a laboratory findsan occasional film specimen with a defect which, properly,should not be used; then, when a defective film specimen isfound, it can be discarded and
31、 an additional film specimen,already at hand, can be substituted. Thus, the extra number offilm specimens (n2) must be at least 2 and, preferably would be3 or 4. The total number of film specimens in a test set wouldthen be the specified number of film specimens plus thedetermined number of extra fi
32、lm specimens (n1+ n2), fromwhich one test result would be obtained.6.2 Determine the number of extra film sets that will beprepared (p2) for the RR. On a practical basis, it is advisable toset p2equal to roughly one half of the number of laboratoriesparticipating in the RR (p1). Then, if mailed test
33、 sets are lost intransit, if after-the-fact recheck testing is needed in one or morelaboratories, or if there are late-entering laboratories into thestudy, additional test sets will be at hand, as needed. For test setpreparation, consider the total number of laboratories to be (p1+ p2).6.3 Determine
34、 the length of the film specimen appropriatefor one test to be conducted (L1).6.4 Calculate the total length of film necessary for theparticipating labs and latent labs (L2) as follows:L25 p11 p2! L1! (1)6.5 To produce one sample of the total number of samples q:6.5.1 Unwind and cut off successive l
35、engths of film, each oflength L2, as depicted in the equation above. Lay out thelength, on a clean flat surface. Place succeeding cut lengths ontop of the first cut length, to form a multilayer stack of film.Build the stack first up to two layers, then up to three layerseach, etc. Continue until sta
36、ck contains the number of pieces offilm necessary to complete the testing plus the predeterminedextra pieces of film (n1+ n2). Do this with each roll of film thatis to be included in the round robin.6.5.2 From the first of the stacks, prepare the total numberof test sets (p1+ p2). Do this by startin
37、g at one end of the stackD4204062and making successive cuts through all layers at the predeter-mined film length for one test specimen (L1). As each test setis obtained, package and label the test set appropriately andmark the package with a sequential number. Keep the packagedtest sets from the ind
38、ividual stacks segregated. Call this acollection of test sets.6.5.3 Repeat 6.5.2 for each of the remaining stacks, in turn,to form segregated collections.6.5.4 By use of random numbers, select one packaged testset from the first collection. Repeat for each of the remainingcollections, to form one gr
39、oup of replicate test sets for testingthe first sample in one laboratory.6.5.5 Continue the selection process of 6.5.4, to end up,finally, with (p1+ p2) groups, each containing r replicate testsets, for testing the first sample in (p1+ p2) laboratories.6.6 Repeat 6.5 for each of the q samples.6.7 Ma
40、ke an assembly by combining one group from eachof the q samples; repeat this process to obtain (p1+ p2)assemblies for testing all q samples in (p1+ p2) laboratories.6.8 Distribute p1assemblies to the p1participating labora-tories. Retain the remaining p2assemblies in case they areneeded subsequently
41、.7. Precision Estimates7.1 After the round-robin study has been completed, analy-ses of variance of the data will provide estimates of componentstandard deviations, S1, S2, and S3, for each of the q samples.7.2 Estimates of within-laboratory and between-laboratoryvariability for each sample, consist
42、ent with the use of symbolsin Practice E 691, are arrived at as follows. In the followingequations, n is the standard number of replicate test specimensrequired for one test result, as dictated by the test method,which is not necessarily the same as the value of n1used in theround-robin study.Sr5 S1
43、2/n 1 S22!12 (2)SL5 S3SR5 Sr21 SL2!128. Keywords8.1 film; round robin; testingSUMMARY OF CHANGESCommittee D20 has identified the location of selected changes to this standard since the last issue(D 4204 - 00) that may impact the use of this standard. (September 1, 2006)(1) Revisions made throughout
44、this practice.ASTM 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 su
45、ch 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 of this standard or for addi
46、tional 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 shouldmake your views known to th
47、e 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).D4204063
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