1、Designation: D3636 11An American National StandardStandard Practice forSampling and Judging Quality of Solid Electrical InsulatingMaterials1This standard is issued under the fixed designation D3636; the number immediately following the designation indicates the year oforiginal adoption or, in the ca
2、se 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. Scope*1.1 This practice covers procedures for obtaining datapertaining to the quality of a lot of e
3、lectrical insulating materialand for making a judgement whether the lot meets therequirements of a material specification.1.2 This practice is not intended to define a producersinternal quality control procedures but is designed to determinethe acceptability of all, or some portion, of a quantity of
4、electrical insulating material that is available for inspection bythe user of the material.1.3 This practice is intended to be used in conjunction withan existing material specification that specifies property char-acteristic limits, acceptable quality level (AQL), standard testmethods, and specific
5、 sampling instructions.1.4 In the absence of a specification as described in 1.3, usethis practice as a guide, after establishment of agreed-uponproperty characteristics, limits, AQL, standard test methods,and specific sampling instructions.1.5 It is intended that this be a practice for inspection b
6、yattributes.1.6 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.
7、Referenced Documents2.1 ASTM Standards:2E300 Practice for Sampling Industrial Chemicals2.2 Military Standard:MIL-STD-105D Sampling Procedures and Tables for In-spection by Attributes32.3 Other Document:ANSI/ASQC A2 -198743. Terminology3.1 Definitions:3.1.1 acceptance number, nthe maximum allowable n
8、um-ber of nonconformities for a given AQL and sample size(lot-sample size).3.1.2 acceptable quality level (AQL), n the maximumpercent nonconforming which, for purposes of sampling in-spection, is considered satisfactory as a process average.3.1.3 critical property, na quantitatively measurable char-
9、acteristic which is absolutely necessary to be met if a materialor product is to provide satisfactory performance for theintended use.3.1.3.1 DiscussionIn some situations, specification re-quirements coincide with customer usage requirements. Inother situations, they may not coincide, being either m
10、ore orless stringent. More stringent sampling (for example, smallerAQL values) is usually used for measurement of characteristicswhich are considered critical. The selection of sampling plansis independent of whether the term defect or nonconformity isappropriate.3.1.4 defect, na departure of a qual
11、ity characteristic fromits intended level, or state, that occurs with a severity sufficientto cause an associated product or service not to satisfy intendednormal, or reasonably foreseeable, usage requirements.3.1.4.1 DiscussionThe terms defect and nonconformityand their derivatives are used somewha
12、t interchangeably in thehistorical and current literature. Nonconformity objectivelydescribes the comparison of test results to specification require-ments, while the term defect has a connotation of predicting thefailure of a product or service to perform its intended functionin use. Since this lat
13、ter connotation is often unintended, theterm nonconformity is preferred in full consensus standards.The selection of any sample plan is independent of whether theterm defect or nonconformity is appropriate.The term defect may be appropriate for specifications mutuallyagreed upon by a producer and a
14、user where specific use conditions areclearly understood. Even in these cases however, use the term defect1This practice is under the jurisdiction of ASTM Committee D09 on Electricaland Electronic Insulating Materials and is the direct responsibility of SubcommitteeD09.94 on Editorial.Current editio
15、n approved April 15, 2011. Published May 2011. Originallyapproved in 1977. Last previous edition approved in 2006 as D3636 06. DOI:10.1520/D3636-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandar
16、ds volume information, refer to the standards Document Summary page onthe ASTM website.3Available from U.S. Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.
17、,4th Floor, New York, NY 10036.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.with caution and consider substituting the term nonconformity.For additional comments, s
18、ee ANSI/ASQC A2-1987 that also states:“When a quality characteristic of a product or service is “evaluated” interms of conformance to specification requirements, the use of the termnonconformity is appropriate.”3.1.5 group AQLthe AQL assigned to a group of materialproperties.3.1.5.1 DiscussionSee 5.
19、2 for additional informationabout the meaning of AQL.3.1.6 lot, nan entity of electrical insulating material orproduct which, insofar as is practicable, consists of a singletype, grade, class, size, or composition that was manufacturedunder essentially the same conditions and is available to theuser
20、 for sampling at one time.3.1.7 lot number, nthe number used by a producer toidentify an entity of electrical insulating material or product.3.1.8 major property, na quantitatively measurable char-acteristic which, if not met, is likely to seriously impair theperformance of a material or product for
21、 the intended use.3.1.8.1 DiscussionIn some situations, specification re-quirements coincide with customer usage requirements. Inother situations, they may not coincide, being either more orless stringent. More stringent sampling (for example, smallerAQL values) is usually used for measurement of ch
22、aracteristicsthat are considered important. The selection of sampling plansis independent of whether the term defect or nonconformity isappropriate.3.1.9 minor property, na characteristic which, if not met,is not likely to materially reduce the performance of a materialor product for the intended us
23、e.3.1.9.1 DiscussionIn some situations, specification re-quirements coincide with customer usage requirements. Inother situations, they may not coincide, being either more orless stringent. More stringent sampling (for example, smallerAQL values) is usually used for measurement of characteristicstha
24、t are considered important. The selection of sampling plansis independent of whether the term defect or nonconformity isappropriate.3.1.10 nonconforming unit, na unit of product containingat least one nonconformity.3.1.11 nonconformities per hundred units, n a calculatedratio of nonconforming units
25、to the number of units inspected,the quotient being multiplied by 100 (See 3.1.13.)3.1.12 nonconformity, na departure of a quality charac-teristic from its intended level or state that occurs with aseverity sufficient to cause a test result not to meet a specifi-cation requirement.3.1.13 percent non
26、conforming, na calculated ratio ofnonconforming units to the number of units inspected, thequotient being multiplied by 100.3.1.14 rejection number, nthe minimum number of non-conformities for a givenAQL and sample size (lot-sample size)which will subject a lot to rejection.3.1.15 sample, none or mo
27、re units of product taken froma lot without regard to the quality of the unit. (Also oftentermed lot sample).3.1.16 sample size, nthe number of units of product takento make up the sample.3.1.16.1 DiscussionThis standard uses only lot samplesizes and not lot sizes since the discriminatory power of a
28、nysampling plan is independent essentially of the size of the lot.The sample size selected by the user for a given acceptablequality level (AQL) is optional depending upon the degree ofprotection desired by the user against the acceptance ofnonconforming lots.3.1.17 test measurement, na quantitative
29、 expression ofone value determined for a property of interest by a singleapplication of a specified test procedure.3.1.18 test result, nthe value that expresses the level of aproperty of the test unit.3.1.18.1 DiscussionAtest result is sometimes a single testmeasurement but usually a test result is
30、computed from severaltest measurements.3.1.19 test specimen, na portion of a test unit upon whichone or more test measurements are made.3.1.20 test unit, na fraction of a unit of product fromwhich one or more test specimens are taken for each property.3.1.20.1 DiscussionIf the unit of product is of
31、insufficientsize to meet the requirements of a testing method: (1) sampleadjacent units of product and aggregate units of product for thetest unit or, (2) obtain a test unit of sufficient size, andrepresentative of the unit of product, from the producer.3.1.21 unit of product, nan entity of electric
32、al insulatingmaterial or product for inspection to determine its classificationas conforming or non-conforming.3.1.21.1 DiscussionAunit of product is established by theuser and may or may not be the same as a unit of purchase,supply, production, or shipment. Some examples of a unit ofproduct are:Bag
33、 Case ReelBarrel Container RollBin Cop SheetBobbin Drum SkidBox Length SpoolBundle Pad TankCar Pail Tank compartmentCarton Pallet Truckload4. Summary of Practice4.1 Instructions are given for obtaining a sample fromwhich specimens are then taken for testing. The test data arecompared to the material
34、 specification and a judgement is thenmade as to whether the material meets the requirements of saidmaterial specification.4.2 This practice has been modeled after MIL-STD-105D.5. Procedure5.1 General Considerations:5.1.1 Assemble the lot of electrical insulating material sothat a lot sample is obta
35、ined in a manner that will minimizebias in the selection of the units of product that will beinspected. A scheme that offers a good chance of minimizingbias is the assignment of numbers to each unit of product andthen using a table of random numbers to select those units ofproduct from which test un
36、its are taken.5.1.2 For a lot of electrical insulating material that is in bulkform (for example, a tank car of powdered resin) take the lotsample from the unit of product in accordance with PracticeE300.D3636 1125.1.3 Take the material to be removed from any unit ofproduct in a random manner. When
37、it is impracticable to meetthis requirement (for example, in the case of long lengths ofmaterial wound onto rolls or large, thick, heavy sheets packedon pallets or skids), economy will dictate the removal ofmaterial from the end of a roll, or the top of a pile, etc. in whichcases the selection canno
38、t be described as “random.”5.1.4 Take the necessary amount of material from the testunit so as to meet the specimen requirements of the various testmethods that will be used to evaluate the material.5.1.5 Refer to the material specification for the allowablemaximum elapsed time between the assembly
39、of the lot forinspection and the disposition of the lot. If the materialspecification (or other pertinent document) does not cover thismatter, the maximum allowable time is 30 calendar days.5.1.6 Exercise care to protect the electrical insulating mate-rial contained in the test unit from which speci
40、mens are to beprepared. An example of this protection is packaging in metalfoil or glass containers so as to prevent or minimize contami-nation of the material from the effects of the environment towhich such material is subjected between sampling and testing.5.1.7 Test units assembled as described
41、above shall bedeemed to be representative of the lot of material beinginspected. Disposition of the lot, or portions thereof will bebased upon the data generated from these test units unlessotherwise agreed upon between the user and the producer.5.2 Establishing Acceptable Quality Levels:5.2.1 Accep
42、table quality levels (AQLs) for each critical,major, and minor property shall be as mutually agreed upon bythe producer and the user. It is also acceptable to establishgroup AQLs for given groups of properties. Disclose theseAQLs in a purchase order, material specification, or in someother document.
43、 This standard is not intended to impose limitsupon the risks acceptable to either the user or the producer.5.2.2 When a user designates some specific value of AQLfor a single nonconformity, it indicates that the users accep-tance sampling plan will accept the great majority of the lotssubmitted by
44、the producer if the process average level ofpercent nonconforming in the lots is no greater than thedesignated value of AQL. The preceding statement is also truefor a group AQL value designated for a group of nonconfor-mities.5.2.2.1 The sampling plans of this standard are so arrangedthat the probab
45、ility of acceptance, at the designatedAQLvalue,depends upon the sample size. For a given AQL, the probabil-ity of acceptance will be generally higher for large sample sizesthan for small sample sizes. The AQL alone does not describethe user protection for individual lots, but more directly relatesto
46、 what a user might expect from a series of lots. Refer to theoperating characteristic curve to determine what protection theuser will have for a specific AQL.5.2.3 The designation of an AQL shall not imply that aproducer has the right to knowingly supply any nonconformingunit of product.5.2.4 The va
47、lues of AQL listed in the accompanying tables(see Section Appendix X1) are known as preferred AQLs. IfanyAQL is designated other than a preferredAQL, these tablesare not applicable.5.3 Sampling Plan Selection:5.3.1 Use the designated AQL and the sample size codeletter from Table 1 to select a sampli
48、ng plan from Tables 2-22.When no sampling plan is available for a given combination ofAQL and code letter, the table directs the user to a differentcode letter. Use the sample size given by the new code letter,not the original code letter.5.3.1.1 It is possible this procedure will lead to differents
49、ample sizes for different classes of nonconformities. In suchcases the user of the electrical insulating material shall desig-nate and authorize, for all classes of nonconformities, theselection and use of the code letter corresponding to the largestsample size derived.TABLE 1 Sample Size Code Letters (See 5.4)D3636 1135.3.1.2 As an alternative to a single sampling plan with anacceptance number of 0, use the plan with an acceptancenumber of 1 with its correspondingly larger sample size for adesignated AQL (where available) when designated and ap
