ASTM_F_2251_-_13.pdf

Designation:F225113Standard Test Method forThickness Measurement of Flexible Packaging Material1This standard is issued under the fixed designation F2251;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 the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the measurement of thickness offlexible packaging materials using contact micrometers.1.2 The Precision and Bias statement for this test methodwas developed using both handheld and bench top micrometerswith foot sizes ranging from 4.8 to 15.9 mm(316to58in.).1.3 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.1.4 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 regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D374 Test Methods for Thickness of Solid Electrical Insu-lation(Withdrawn 2013)3D5947 Test Methods for Physical Dimensions of SolidPlastics SpecimensD6988 Guide for Determination of Thickness of Plastic FilmTest SpecimensE171 Practice for Conditioning and Testing Flexible BarrierPackagingE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2.2 ANSI/ASQ Standards:4ANSI/ASQC Z1.4 Sampling Procedures and Tables for In-spection by AttributesANSI/ASQC Z1.9 Sampling Procedures and Tables for In-spection by Variables3.Terminology3.1 Definitions:3.1.1 bench micrometertabletop measurement system us-ing a dead weight or spring.3.1.2 footthe moving component of the micrometer thatcomes in contact with the sample.4.Significance and Use4.1 This test method provides a means for measuring athickness dimension.Accurate measurement of thickness canbe critical to meeting specifications and characterizing process,product,and material performance.4.2 This test method does not address acceptability criteria.These need to be jointly determined by the user and producerof the product.Repeatability and reproducibility of measure-ment is shown in the Precision and Bias section.Attentionshould be given to the inherent variability of materials beingmeasured as this can affect measurement outcome.5.Apparatus5.1 Mechanical gage,suitable for measuring thickness:5.1.1 The thickness gage may be either a bench or hand-heldmechanical model.5.1.2 The gage should be capable of accurately measuring inincrements of 2.5 m(0.0001 in.).5.1.3 The foot size and foot pressure should be known andidentified.Because of the compressibility of different materialsit is important when comparing results between differentlaboratories that the size of the foot and pressure be the same.Refer to Guide D6988 for further guidance on foot pressures.5.1.4 It is recommended that a calibration be performed onthe apparatus used and certified to a recognized industrystandard such as National Institute of Standards and Technol-ogy(NIST).1This test method is under the jurisdiction ofASTM Committee F02 on FlexibleBarrier Packaging and is the direct responsibility of Subcommittee F02.20 onPhysical Properties.Current edition approved Aug.1,2013.Published October 2013.Originallyapproved in 2003.Last previous edition approved in 2008 as F2251 03(Reap-proved 2008).DOI:10.1520/F2251-13.2For referenced ASTM standards,visit the ASTM website,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.4Available from American National Standards Instititute(ANSI)25 W.43rd St.,4th Floor,New York,NY 10036.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 NOTE1Test Methods D5947 and D374 give guidance on methods forchecking calibration and parallelism.6.Sampling6.1 The number of samples tested should be adequate to bepredictive of performance.Caution should be taken wheneliminating samples with defects as this can bias results.6.2 SeeANSI/ASQC Z1.4 or Z1.9 for guidance on samplingplans and practices.7.Conditioning7.1 Conditioning of the samples will depend on the materialunder evaluation.If conditioning before testing is appropriate,normal,and desirable,refer to Specification E171 for guidance.8.Procedure8.1 Review applicable specifications,drawings,or proce-dures.Specify unit of measure to be used and directions relatedto precision require