1、Designation: B 602 88 (Reapproved 2005)Standard Test Method forAttribute Sampling of Metallic and Inorganic Coatings1This standard is issued under the fixed designation B 602; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the yea
2、r of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method gives sampling plans that are intendedfor use in the inspection of metallic and inorganic coati
3、ngs forconformance to ASTM standard specifications.1.2 The plans in this test method, except as noted, have beenselected from some of the single sampling plans of MIL-STD-105D.The specific plans selected are identified inTables 1-3 ofthis test method. The plan of Table 4, which is used fordestructiv
4、e testing, is not from the Military Standard. Thisstandard does not contain the Military Standards requirementfor tightened inspection when the quality history of a supplieris unsatisfactory.1.3 The plans are based on inspection by attributes, that is,an article of product is inspected and is classi
5、fied as eitherconforming to a requirement placed on it, or as nonconforming.Sampling plans based on inspection by variables are given inTest Method B 762. Variables plans are applicable when a testyields a numerical value for a characteristic, when the speci-fication imposes a numerical limit on the
6、 characteristic, andwhen certain statistical criteria are met. These are explained inTest Method B 762.1.4 The plans in this test method are intended to begenerally suitable. There may be instances in which tighter orlooser plans or ones that are more discriminating are desired.Additional plans that
7、 may serve these needs are given in GuideB 697. Also, Guide B 697 describes the nature of attributesampling plans and the several factors that must be consideredin the selection of a sampling plan. More information and aneven greater selection of plans are given in MIL-STD-105D,MIL-STD-414, ANSI/ASQ
8、C Z1.9, Refs (1-7)2, and in GuideB 697.1.5 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 l
9、imitations prior to use.2. Referenced Documents2.1 ASTM Standards:3B 697 Guide for Selection of Sampling Plans for Inspectionof Electrodeposited Metallic and Inorganic CoatingsB 762 Test Method of Variables Sampling of Metallic andInorganic Coatings2.2 ANSI Standard:4ANSI/ASQC Z1.9-1979 Sampling Pro
10、cedures and Tablesfor Inspection by Variables for Percent Non-Conformance2.3 Military Standards:5MILSTD105D Sampling Procedures and Tables for In-spection by AttributesMIL-STD-414 Sampling Procedures and Tables for Inspec-tion by Variables for Percent Defective3. Terminology3.1 Definitions:3.1.1 des
11、tructive testtest that destroys the tested article ormakes it nonconforming to a requirement.3.1.2 inspection lotcollection of articles of the same kindthat is submitted to inspection for acceptance or rejection as agroup.3.1.3 nondestructive testtest that neither destroys thetested article nor make
12、s it nonconforming to a requirement.3.1.4 samplearticles randomly selected from an inspec-tion lot whose quality is used to decide whether or not theinspection lot is of acceptable quality.4. Significance and Use4.1 Sampling inspection permits the estimation of the over-all quality of a group of pro
13、duct articles through the inspectionof a relatively small number of product items drawn from thegroup.4.2 The selection of a sampling plan provides purchasersand sellers a means of identifying the minimum quality levelsthat are considered to be satisfactory.1This test method is under the jurisdictio
14、n ofASTM Committee B08 on Metallicand Inorganic Coatings and is the direct responsibility of Subcommittee B08.10 onTest Methods.Current edition approved May 15, 2005. Published June 2005. Originallyapproved in 1975. Last previous edition approved in 1999 as B 602 88 (1999).2The boldface numbers in p
15、arentheses refer to the list of references at the end ofthis standard.3For 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
16、 website.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.5Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,Section D, 700 Robbins Ave., Philadelphia, PA 19111-50981Copyright ASTM International, 100 Barr Harbor Drive, PO B
17、ox C700, West Conshohocken, PA 19428-2959, United States.4.3 Because sampling plans will only yield estimates of thequality of a product, the results of the inspection are subject toerror. Through the use of sampling plans, the risk of error isknown and controlled.5. General5.1 In sampling inspectio
18、n, a relatively small number ofarticles (the sample) is selected randomly from a larger numberof articles (the inspection lot) and is inspected for conformanceto the requirements placed on the articles. Based on the results,a decision is made either to accept or reject the inspection lot.Sampling is
19、 used, rather than inspection of every article in alot, to reduce cost. Also, some test methods are destructive, inwhich cases sampling inspection must be used to avoiddestroying the lot.5.2 There is always a risk that a sample will not berepresentative of the lot from which it is drawn. The larger
20、thesample, the smaller this risk, but, the larger the cost ofinspection. So the selection of a sampling plan involves thebalancing of the costs of inspection against the consequencesof accepting an undesirable number of nonconforming articles.If every article in an inspection lot conforms to its req
21、uire-ments, every article in the sample will conform also. Such lotswill always be accepted. If only a few articles in an inspectionlot are nonconforming, the chances are that the sample willindicate that the lot is acceptable; but there is a small chancethat the sample will indicate that the lot is
22、 unacceptable. Thelarger the proportion of nonconforming articles in an inspec-tion lot, the more likely it will be that the sample will indicatethat the lot is unacceptable. In the extreme case of every articlein an inspection lot being nonconforming, a sample will alwaysindicate that the lot is un
23、acceptable.TABLE 1 Level ISampling Plan for Nondestructive TestsAInspection Lot Size Sample SizeAcceptanceNumberAQL, % 50/50 Point, % LQL, % AOQL,%1to 20Ball 0 . . . .21 to 280 20 0 0.26 3.4 11.0 1.8281 to 1 200 80 1 0.44 2.1 4.8 1.11 201 to 3 200 125 2 0.65 2.1 4.3 1.13 201 to 10 000 200 3 0.68 1.8
24、 3.3 0.9710 001 to 35 000 315 5 0.83 1.8 2.9 1.0Over 35 000 500 7 0.80 1.5 2.4 0.90ATaken from MIL-STD-105D, Single Sampling Plan, Level II, AQL = 0.65, Normal Inspection.BThe smallest lots are 100 % inspected, and so there is no sampling risk. For this reason, there are no AQL, etc.TABLE 2 Level II
25、Sampling Plan for Nondestructive TestsAInspection Lot Size Sample SizeAcceptanceNumberAQL, % 50/50 Point, % LQL, % AOQL,%1to 8Ball 0 . . . .9 to 90 8 0 0.64 8.3 25 4.691 to 280 32 1 1.1 5.2 12 2.6281 to 500 50 2 1.7 5.3 10 2.7501 to 1 200 80 3 1.7 4.6 8.2 2.41 201 to 3 200 125 5 2.1 4.5 7.4 2.53 201
26、 to 10 000 200 7 2.0 3.9 5.9 2.210 001 to 35 000 315 10 2.0 3.4 4.9 2.1Over 35 000 500 14 1.9 2.9 4.0 1.9ATaken from MIL-STD-105D, Single Sampling Plan, Level II, AQL = 1.5, Normal Inspection.BThe smallest lots are 100 % inspected, and so there is no sampling risk. For this reason, there are no AQL,
27、 etc.TABLE 3 Level III Sampling Plan for Nondestructive TestsAInspection Lot Size Sample SizeAcceptanceNumberAQL, % 50/50 Point, % LQL, % AOQL,%1to 5Ball 0 . . . .6 to 50 5 0 1.0 12.9 37 7.451 to 150 20 1 1.8 8.2 18 4.2151 to 280 32 2 2.6 8.2 16 4.3281 to 500 50 3 2.8 7.3 13 3.9501 to 1 200 80 5 3.3
28、 7.1 11 4.01 201 to 3 200 125 7 3.2 6.1 9.4 3.63 201 to 16 000 200 10 3.1 7.3 7.7 3.316 001 to 35 000 315 14 2.9 4.7 6.4 3.0Over 35 000 500 21 3.0 4.3 5.6 2.9ATaken from MIL-STD-105D, Single Sampling Plan, Level II, AQL = 2.5, Normal Inspection.BThe smallest lots are 100 % inspected, and so there is
29、 no sampling risk. For this reason, there are no AQL, etc.TABLE 4 Sampling Plan for Destructive TestAInspection Lot SizeSampleSizeAccept-anceNumberAQL,%50/50Point, %LQL,%1 to 25 2 0 2.5 29 6826 to 1 200 13 1 2.8 13 271201 to 35 000 32 2 2.6 8.3 16Over 35 000 55 3 2.5 6.6 12AAOQLs are not given becau
30、se destructive tests cannot be used to screenrejected lots. This plan is not found in MIL-STD-105D.B 602 88 (2005)25.3 For a given sampling plan, the chance of accepting aninspection lot that contains nonconforming items is oftendescribed in terms of theAcceptance Quality Level (AQL) andthe Limiting
31、 Quality Level (LQL).TheAQLis the quality levelthat is considered to be acceptable.The LQLis the quality levelthat is considered to be barely tolerable. A sampling plan isselected that will accept most submitted inspection lots ofAQLquality and reject most lots of LQL quality. In this test methodthe
32、 AQL given for a sampling plan is the quality level of lots(expressed as the percentage of nonconforming articles) thathave a 95 % chance of being accepted. The LQL is the qualitylevel of lots that have a 10 % chance of being accepted or, inother words, a 90 % chance of being rejected. Also given wi
33、theach sampling plan in this test method, is the quality level of aninspection lot that has a 50 % chance of being accepted. This iscalled the 50/50 point.5.4 If all of the articles in a rejected inspection lot areinspected, and if nonconforming articles are removed andreplaced with conforming artic
34、les, and then if the now 100 %conforming lot is resubmitted, the average quality level for aseries of lots taken as a whole will be better because of theaddition of the 100 % conforming lot. When the incoming lotsare of a good quality level, the average quality level of a seriesof lots will be even
35、better when the rejected lots are screenedand resubmitted. When incoming lots are of a poor qualitylevel, the average quality of a series of lots will again be goodbecause many of the incoming lots will be rejected andupgraded. At intermediate quality levels of incoming lots, theaverage quality leve
36、l of a series of lots will not be as good asin either of the above cases. The poorest average quality levelthat can result from the use of a given sampling plan whenscreening of rejected lots is done is called the AverageOutgoing Quality Limit (AOQL). If corrective action is takenby the supplier so
37、that there is a low rejection rate of initiallysupplied lots, the average quality level will be better than theAOQL (Note 1). This 100 % inspection of rejected lots cannot,of course, be used if the inspection test method is destructive.Screening of rejected lots will substantially increase the cost
38、ofinspection if the incoming lots are much worse than AQLquality. Screening is to be used only when required by thepurchaser.NOTE 1The AOQLs given for Tables 1-3 are strictly correct onlywhen the sample is small with respect to the lot. If the sample isconsistently a significant part of the lot, the
39、 correct AOQL will be smallerthan the tabulated value. The correct values are obtained by multiplyingthe tabulated values by:1 sample size/lot size5.5 This test method contains four sampling plans.Three areintended to be used when the inspection methods are nonde-structive. One of these (Table 2) is
40、 considered to be standardand is the one that is followed unless the user of this methodspecifies either a higher quality level (Table 1) or a lower one(Table 3). The fourth plan is intended to be used when theinspection methods are destructive. This last plan utilizessmaller samples and so reduces
41、the cost of inspection but witha sacrifice in the ability to distinguish between acceptable andunacceptable lots.6. Ordering Information6.1 Unless otherwise specified by the purchaser, the sam-pling plan given in Table 2 will be used for nondestructivetesting, and the plan given in Table 4 for destr
42、uctive testing.6.2 When either a nondestructive or a destructive test can beused to inspect an article for conformance to a particularrequirement, the purchaser should specify which test is to beused. When a test is neither clearly nondestructive nor destruc-tive (see Note 2, 8.3), the purchaser sho
43、uld specify which it isconsidered to be.7. Formation of Inspection Lot7.1 An inspection lot shall be formed from articles that areof the same kind, that have been produced to the samespecification, and that have been coated by a single supplier atone time or at approximately the same time under esse
44、ntiallyidentical conditions.8. Sampling8.1 GeneralA sample shall be selected from the inspec-tion lot. If the test method to be used is nondestructive, thesample size shall be that directed in 8.2. If the test method isdestructive, the sample size shall be that directed in 8.3.8.2 Nondestructive Tes
45、tsFor nondestructive testing, thesize of the sample shall be that specified for the sampling planlevel that is required by the purchaser. The sampling plans aregiven for Level I in Table 1, for Level II in Table 2, and forLevel III in Table 3. If the purchaser does not specify the level,Level II sha
46、ll be used.8.3 Destructive TestsFor destructive testing, the size ofthe sample shall be that specified in Table 4.NOTE 2The nature of a destructive test can be such that the testedarticle can be reclaimed, for example by stripping and reapplying thecoating. Other tests can destroy the coating in non
47、essential locations, inwhich case the item can still be functional. In these instances the purchaserneeds to decide and state whether the tests are to be considered destructiveor nondestructive.NOTE 3The plan given for destructive tests uses smaller samples thanthe plans given for nondestructive tes
48、ts. There may be cases in whichdestruction of even these smaller quantities is undesirable. For example,the articles may be expensive or the inspection lot may be small. Often insuch cases test specimens are coated along with the articles and are usedto represent them in the destructive tests. The p
49、ermission to use testspecimens and the requirements covering them and their use should be setforth in the applicable coating specification, purchase order, or othergoverning document.8.4 The sample shall be drawn from the inspection lotrandomly, that is, in a manner that assures each article an equalchance of being selected regardless of other considerationssuch as its location in the inspection lot, its appearance, itsquality, its location on a fixture during coating, and itschronological relationship to the other articles. Random sam-pling procedures are given in
