1、Designation: D4204 06 D4204 12Standard 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 similar or equivalent ISO 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
5、Specific to This Standard:3.1.1 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
6、 produce a single test result 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 variabili
7、ty, inasmuch as round-robin 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 s
8、tudy.3.1.3 test resultthe value (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 dim
9、ensions, that is to be cut 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
10、one test result for each property.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 fi
11、lm specimens in each test setp1 = 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 Sept. 1, 2006Aug. 1, 2012
12、. Published September 2006September 2012. Originally approved in 1982. Last previous edition approved in 20002006as D4204 - 00.D4204 - 06. DOI: 10.1520/D4204-06.10.1520/D4204-12.2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org
13、. For Annual Book of ASTM Standardsvolume 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 m
14、ay not be technically possible to 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 t
15、he end of this standardCopyright 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 spec
16、imenL2 = total length of film necessary 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 d
17、eviation for within-laboratory variability 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 de
18、viation of a between-laboratory 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 Th
19、is practice assumes that the essential 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)
20、the number of replicate test results 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
21、undulydistort the conclusions drawn 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 variabili
22、ty (S4) should is expected to be small. The larger the value of standard deviationfor within-sample variability (S4), the greater will be the adverse effect upon conclusions drawn from round-robin data regardingtest method precision.5.1.1 For any sample, the total observed variability will always co
23、ntain the component of standard deviation 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-
24、laboratory within-dayvariability (S1), 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
25、to be dealt with as conveniently as possible.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-laborat
26、ory variability (S3 ) that is not inflated 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),
27、so that the estimate of within-laboratory 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
28、 completely random selection of all filmspecimens 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 p
29、roperty, or properties, tobe measured did 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 samples (n1) fromeach sample. If the range of property levels thus found is narrower than is deemed a
30、ppropriate for the study, it may be is 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
31、way test sets are madeup, as described 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 sp
32、ecimens between the top and bottom film 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, inset. In the event a laboratory finds an occasional filmspecimen with a defect which, properly, should not be used; then,
33、when a defective film specimen is found, a defective filmspecimen, it can be discarded and an additional film specimen, already at hand, can be substituted. Thus, the extra number of filmD4204 122specimens (n2) must be at least 2 and, preferably would be 3 or 4. The total number of film specimens in
34、 a test set would thenbe the specified number of film specimens plus the determined number of extra film specimens (n1 + n2), from which one test resultwould be obtained.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 p2
35、equal 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 needed in one or more laboratories, or if there are late-entering laboratories into the study,additional test sets will be at hand,
36、 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 be conducted (L1).6.4 Calculate the total length of film necessary for the participating labs and latent labs (L2) as follows:L25p
37、11p2!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 above. Lay out the length,on a clean flat surface. Place succeeding cut lengths on top of the first cut length, to form a multila
38、yer 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 complete the testing plus the predetermined extra pieces of film (n1 + n2). Do this with each roll of film that is to be includedin
39、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 through all layers at the predetermined film length for one test specimen (L1). As each test set is obtained,package and label th
40、e 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 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, s
41、elect 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 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 repl
42、icate 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 the q samples; repeat this process to obtain (p1 + p2) assembliesfor testing all q samples in (p1 + p2) laboratories.6.8 Distribute
43、 p1 assemblies to the p1 participating laboratories. Retain the remaining p2 assemblies in case they are neededsubsequently.7. Precision Estimates7.1 After the round-robin study has been completed, analyses of variance of the data will provide estimates of componentstandard deviations, S1, S2, and S
44、3, 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, are arrived at as follows. In the following equations, n is the standard number of replicate test specimens requiredfor one test res
45、ult, 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. Keywords8.1 film; round robin; testingD4204 123SUMMARY OF CHANGESCommittee D20 has identified the location of selected changes to this st
46、andard since the last issue(D4204 - 00D4204 - 06) that may impact the use of this standard. (September(August 1, 2006)2012)(1) Revisions made throughout this practice.Revised ISO equivalency statement in Note 1.(2) Editorial changes were made throughout.(3) Removed permissive language.ASTM Internati
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48、r 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 standardsand should b
49、e 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 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 ab
