ASTM_B_762_-_90_2016.pdf

Designation:B76290(Reapproved 2016)Standard Test Method ofVariables Sampling of Metallic and Inorganic Coatings1This standard is issued under the fixed designation B762;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 provides sampling plans that areintended for use in the inspection of metallic and inorganiccoatings on products for the purpose of deciding whethersubmitted lots of coated products comply with the specifica-tions applicable to the coating.1.2 The sampling plans are variables plans.In plans of thistype,several articles of product are drawn from a productionlot.A characteristic of the coating on the drawn articles ismeasured.The values obtained are used to estimate the numberof articles in the lot that do not conform to a numerical limit,for example a minimum thickness.The number is compared toa maximum allowable.1.3 Variables plans can only be used when the characteristicof interest is measurable,the test method gives a numericalmeasure of the characteristic,and the specification places anumerical limit on the measured value.It is also necessary thatthe variation of the characteristic from article to article in aproduction lot be normally distributed(see Appendix X2).Each article must be tested in the same way(for example,coating thickness must be measured at the same location,seeX2.7)so that the values from article to article are comparable.If one or more of these conditions are not met,a variables plancannot be used.Instead,an attributes plan must be used.Theseare given in Test Method B602 and Guide B697.1.4 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:2B602 Test Method for Attribute Sampling of Metallic andInorganic CoatingsB697 Guide for Selection of Sampling Plans for Inspectionof Electrodeposited Metallic and Inorganic Coatings2.2 ANSI Standards:3ANSI/ASQC Z1.9-1979 Sampling Procedures and Tablesfor Inspection by Variables for Percent Non-ConformanceANSI/ASQC Z1.4-1981 Sampling Procedures and Tablesfor Inspection by Attributes2.3 Military Standards:4MIL-STD-105 Sampling Procedures and Tables for Inspec-tion by AttributesMIL-STD-414 Sampling Procedures and Tables for Inspec-tion by Variables for Percent Defective3.Definitions3.1 destructive testtest that destroys the tested article ormakes it nonconforming to a requirement.3.2 nondestructive testtest that neither destroys the testedarticle nor makes it nonconforming to a requirement.3.3 inspection lotcollection of articles of the same kindthat is submitted to inspection for acceptance or rejection as agroup.3.4 samplearticles randomly selected from an inspectionlot whose quality is used to decide whether or not theinspection lot is of acceptable quality.3.5 standard deviationmeasure of dispersion equal to thesquare root of the mean of the squares of the deviations fromthe arithmetic mean of the distribution(see 9.2.6).4.Summary of Test Method4.1 The plans in this test method provide the same protec-tion as the attributes plans in Tables 1,2,and 3 of Test MethodB602 and are interchangeable with them when the conditionsnecessary for variables sampling exist.This method has noplan comparable to Table 4 of Test Method B602,becausevariables plans are subject to an excessive probability of errorwhen the number of nonconforming articles in a lot is expected1This test method is under the jurisdiction ofASTM Committee B08 on Metallicand Inorganic Coatings and is the direct responsibility of Subcommittee B08.10 onTest Methods.Current edition approved Nov.1,2016.Published November 2016.Originallyapproved in 1986.Last previous edition approved in 2010 as B762 90(2010).DOI:10.1520/B0762-90R16.2For 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.3Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.4Available from Standardization Documents Order Desk,DODSSP,Bldg.4,Section D,700 Robbins Ave.,Philadelphia,PA 19111-5098.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 to be approximately 1%or less as it is for the Table 4 plan.Also for this reason,comparable variables plans are not givenfor the smallest lot sizes of Tables 1 and 2 of Test MethodB602.The plans of Table 4,and Tables 1 and 2 in Test MethodB602 are descr