1、Designation: D4204 12D4204 16Standard Practice forPreparing Plastic Film Specimens for a Round-Robin Study1This standard is issued under the fixed designation D4204; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This practice covers the preparation of test sets of plastic film specimens for subsequent use in an interlaboratoryround-
3、robin study to evaluate the precision of a test method.1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability
4、of regulatorylimitations prior to use.NOTE 1There is no known ISO equivalent to this standard.2. Referenced Documents2.1 ASTM Standards:2E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method3. Terminology3.1 Definitions of Terms Specific to This Standard:3
5、.1.1 film specimenone piece of a sample obtained by cutting across the width of the sample and to a length such that onetest specimen can subsequently be prepared.NOTE 2For any sample in a laboratory, the specified number of film specimens in a test unit (n1) are tested to produce a single test resu
6、lt in ashort-time period, while replicate test results are obtained over a longer time period. Thus, there are within-laboratory components of variability for bothshort-term and long-term testing. This practice calls these within-day and between-day components of variability, inasmuch as round-robin
7、 protocols oftenspecify that replicate test results be obtained on different days.3.1.2 samplea quantity of film of a width appropriate to the test method under study and of a length sufficient to yield the totalnumber of film specimens needed for the planned round-robin study.3.1.3 test resultthe v
8、alue (usually, the arithmetic average) of the property derived from one test unit.3.1.4 test seta group of several film specimens, in a number greater than that specified for a test unit.3.1.5 test specimenthe individual piece of film to be tested, usually of specified dimensions, that is to be cut
9、from one filmspecimen and tested, to produce one value of the property, or properties, by the test method under study.3.1.6 test unita specified number of film specimens from which an equal number of test specimens is to be prepared and testedin a short-time span to yield one test result for each pr
10、operty.3.2 Abbreviations:RR = round-robin studyq = number of samples to be used in the RRr = total number of film assemblies that will be needed for each lab to complete the necessary testingn1 = specified number of film specimens in a test unitn2 = number of additional film specimens in each test s
11、etp1 = number of laboratories participating in the RR1 This practice is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.19 on Film, Sheeting, and MoldedProducts.Current edition approved Aug. 1, 2012Nov. 1, 2016. Published September 2012No
12、vember 2016. Originally approved in 1982. Last previous edition approved in 20062012as D4204 - 06.D4204 - 12. DOI: 10.1520/D4204-12.10.1520/D4204-16.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standa
13、rdsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible t
14、o adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright
15、 ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1p2 = number of additional “latent” laboratories provided for in the specimen preparation procedureL1 = film-specimen length appropriate for preparing one test specimenL2 = total length of film ne
16、cessary to produce samples fro participating plus latent laboratories; L2 = (p1 + p2) (L1)SD = standard deviation for a single source of variability for one given sampleS1 = standard deviation for within-laboratory within-day variability of a test valueS2 = standard deviation for within-laboratory v
17、ariability of a test resultS3 = standard deviation for between-laboratory variability of a test resultS4 = standard deviation for within-sample variabilitySr = standard deviation of a within-laboratory single test result for one given sample on any daySR = standard deviation of a between-laboratory
18、single test result for one given sample on any day4. Significance and Use4.1 This practice is intended to assist task groups participating in a round-robin study with the preparation of test sets of filmspecimens from film samples in the form of rolls on a core.4.2 This practice assumes that the ess
19、ential features of the round-robin protocol have already been established by following theguidance of Practice E691. In particular, it is assumed that the following are known: (1) the number of film samples to be used,(2) the number of participating laboratories, (3) the number of replicate test res
20、ults to be generated by each laboratory for eachsample, and (4) the number of test specimens required to yield one test result for each sample.4.3 In accordance with this practice, samples are partitioned into test sets so that real within-sample variability will not undulydistort the conclusions dr
21、awn from statistical analyses of the data generated in the round-robin study.5. Sample Selection5.1 Select the number of samples q to be used in the round-robin (RR) study that would be expected to be uniform for whichthe standard deviation for within-sample variability (S4) is expected to be small.
22、 The larger the value of standard deviation forwithin-sample variability (S4), the greater will be the adverse effect upon conclusions drawn from round-robin data regarding testmethod precision.5.1.1 For any sample, the total observed variability will always contain the component of standard deviati
23、on for within-samplevariability (S4). In the typical study, sample standard deviation for within-sample variability (S4 ) is not estimated separately; theresult is an overestimation of one or more of the components of variability: standard deviation for within-laboratory within-dayvariability (S1),
24、standard deviation for within-laboratory between-day variability, (S2), standard deviation for between-laboratoryvariability (S3) that the study is designed to estimate. Because of this, standard deviation for within-sample variability (S4) is anuisance factor to be dealt with as conveniently as pos
25、sible.5.1.2 It is preferable to confound standard deviation for within-sample variability (S4) with the within-laboratory componentsof variability, of within-day and between-day components of variability (S1 and S2), and to obtain an estimate of between-laboratory variability (S3) that is not inflat
26、ed by within-sample variability (S4). This practice is intended to accomplish this. In mostcases, in accordance with this practice, the standard deviation for within-sample variability (S4) is confounded only withwithin-laboratory within-day variability (S1), so that the estimate of within-laborator
27、y between-day variability (S2) is also notinflated by the standard deviation for within-sample variability, (S4). The confounding of standard deviation for within-samplevariability (S4) with only within-laboratory within-day variability (S1) is equivalent to a completely random selection of all film
28、specimens from the film sample.5.1.3 The best source of samples is from commercial or laboratory extrusion operations that have demonstrated the capabilityto produce film under conditions that have shown that appreciable systematic trends in the level of the property, or properties, tobe measured di
29、d not occur as the sample was being fabricated.5.2 Before preparing test sets as described in Section 6, have one laboratory test the specified number of test samplesspecimens(n1) from each sample. If the range of property levels thus found is narrower than is deemed appropriate for the study, it is
30、 desirableto obtain one or more additional samples, to replace one or more of the number of samples to be used in the RR (q) collectedinitially.6. Procedure6.1 Determine the number of extra film specimens to be used for each test (n2) for the RR. In view of the way test sets are madeup, as described
31、 subsequently, there will always be two “sacrifice” film specimens in a test set, one on top and one on bottom ofthe stack, that serve to protect the integrity of the film specimens in between. These two are not to be used; always take testspecimens from film specimens between the top and bottom fil
32、m specimens in the test set. In addition, it is usually advisable toinclude a minimum of one or two extra film specimens in each test set. In the event a laboratory finds a defective film specimen,it can be discarded and an additional film specimen, already at hand, can be substituted. Thus, the ext
33、ra number of film specimens(n2) must be at least 2 and, preferably would be 3 or 4. The total number of film specimens in a test set would then be the specifiednumber of film specimens plus the determined number of extra film specimens (n1 + n2), from which one test result would beobtained.D4204 162
34、6.2 Determine the number of extra film sets that will be prepared (p2) for the RR. On a practical basis, it is advisable to set p2equal to roughly one half of the number of laboratories participating in the RR (p1). Then, if mailed test sets are lost in transit,if after-the-fact recheck testing is n
35、eeded in one or more laboratories, or if there are late-entering laboratories into the study,additional test sets will be at hand, as needed. For test set preparation, consider the total number of laboratories to be (p1 + p2).6.3 Determine the length of the film specimen appropriate for one test to
36、be conducted (L1).6.4 Calculate the total length of film necessary for the participating labs and latent labs (L2) as follows:L25p11p2!L1! (1)6.5 To produce one sample of the total number of samples q:6.5.1 Unwind and cut off successive lengths of film, each of length L2, as depicted in the equation
37、 above. Lay out the length,on a clean flat surface. Place succeeding cut lengths on top of the first cut length, to form a multilayer stack of film. Build the stackfirst up to two layers, then up to three layers each, etc. Continue until the stack contains the number of pieces of film necessaryto co
38、mplete the testing plus the predetermined extra pieces of film (n1 + n2). Do this with each roll of film that is to be includedin the round robin.6.5.2 From the first of the stacks, prepare the total number of test sets (p1 + p2). Do this by starting at one end of the stack andmaking successive cuts
39、 through all layers at the predetermined film length for one test specimen (L1). As each test set is obtained,package and label the test set appropriately and mark the package with a sequential number. Keep the packaged test sets from theindividual stacks segregated. Call this a collection of test s
40、ets.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 test set from the first collection. Repeat for each of the remainingcollections, to form one group of replicate test sets for testing the first sample
41、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 test sets, fortesting the first sample in (p1 + p2) laboratories.6.6 Repeat 6.5 for each of the q samples.6.7 Make an assembly by combining one group from each of t
42、he q samples; repeat this process to obtain (p1 + p2) assembliesfor testing all q samples in (p1 + p2) laboratories.6.8 Distribute p1 assemblies to the p1 participating laboratories. Retain the remaining p2 assemblies in case they are neededsubsequently.7. Precision Estimates7.1 After the round-robi
43、n study has been completed, analyses 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-laboratory variability for each sample, consistent with the use of symbols inPractice E691, ar
44、e arrived at as follows. In the following equations, n is the standard number of replicate test specimens requiredfor one test result, as dictated by the test method, which is not necessarily the same as the value of n1 used in the round-robin study.Sr 5S12/n1S22!12 (2)SL 5S3SR 5Sr21SL2!128. Keyword
45、s8.1 film; round robin; testingD4204 163SUMMARY OF CHANGESCommittee D20 has identified the location of selected changes to this standard since the last issue(D4204 - 06D4204 - 12) that may impact the use of this standard. (August(November 1, 2012)2016)(1) Revised ISO5.2 equivalency statement in Note
46、 1.(2) Editorial changes were made throughout.(3) Removed permissive language.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 valid
47、ity of any such patent rights, and the 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 commen
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49、t received a fair hearing you shouldmake 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 Copy
