ASTM D3636-00
(Practice)Standard Practice for Sampling and Judging Quality of Solid Electrical Insulating Materials
Standard Practice for Sampling and Judging Quality of Solid Electrical Insulating Materials
SCOPE
1.1 This practice covers procedures for obtaining data pertaining to the quality of a lot of electrical insulating material and for making a judgement whether the lot meets the requirements of a material specification.
1.2 This practice is not intended to define a producer's internal quality control procedures but is designed to determine the acceptability of all, or some portion, of a quantity of electrical insulating material that is available for inspection by the user of the material.
1.3 This practice is intended to be used in conjunction with an existing material specification that specifies property characteristic limits, acceptable quality level (AQL), standard test methods, and specific sampling instructions.
1.4 In the absence of a specification as described in 1.3, this practice may be used as a guide, after establishment of agreed-upon property characteristics, limits, AQL, standard test methods, and specific sampling instructions.
1.5 It is intended that this be a practice for inspection by attributes.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
An American National Standard
Designation:D3636–00
Standard Practice for
Sampling and Judging Quality of Solid Electrical Insulating
Materials
This standard is issued under the fixed designation D 3636; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope ANSI/ASQC A2 -1987
1.1 This practice covers procedures for obtaining data
3. Terminology
pertainingtothequalityofalotofelectricalinsulatingmaterial
3.1 Definitions:
and for making a judgement whether the lot meets the
3.1.1 acceptance number, n—themaximumallowablenum-
requirements of a material specification.
ber of nonconformities for a given AQL and sample size
1.2 This practice is not intended to define a producer’s
(lot-sample size).
internalqualitycontrolproceduresbutisdesignedtodetermine
3.1.2 acceptable quality level (AQL), n— the maximum
the acceptability of all, or some portion, of a quantity of
percent nonconforming which, for purposes of sampling in-
electrical insulating material that is available for inspection by
spection, is considered satisfactory as a process average.
the user of the material.
3.1.3 critical property, n—aquantitativelymeasurablechar-
1.3 This practice is intended to be used in conjunction with
acteristic which is absolutely necessary to be met if a material
an existing material specification that specifies property char-
or product is to provide satisfactory performance for the
acteristic limits, acceptable quality level (AQL), standard test
intended use.
methods, and specific sampling instructions.
3.1.3.1 Discussion—In some situations, specification re-
1.4 In the absence of a specification as described in 1.3, this
quirements coincide with customer usage requirements. In
practice may be used as a guide, after establishment of
other situations, they may not coincide, being either more or
agreed-upon property characteristics, limits, AQL, standard
less stringent. More stringent sampling (for example, smaller
test methods, and specific sampling instructions.
AQLvalues)isusuallyusedformeasurementofcharacteristics
1.5 It is intended that this be a practice for inspection by
which are considered critical. The selection of sampling plans
attributes.
is independent of whether the term defect or nonconformity is
1.6 This standard does not purport to address all of the
appropriate.
safety concerns, if any, associated with its use. It is the
3.1.4 defect, n—a departure of a quality characteristic from
responsibility of the user of this standard to establish appro-
its intended level, or state, that occurs with a severity sufficient
priate safety and health practices and determine the applica-
tocauseanassociatedproductorservicenottosatisfyintended
bility of regulatory limitations prior to use.
normal, or reasonably foreseeable, usage requirements.
2. Referenced Documents 3.1.4.1 Discussion—The terms defect and nonconformity
and their derivatives are used somewhat interchangeably in the
2.1 ASTM Standards:
historical and current literature. Nonconformity objectively
E 300 Practice for Sampling Industrial Chemicals
describesthecomparisonoftestresultstospecificationrequire-
2.2 Military Standard:
ments,whiletheterm defecthasaconnotationofpredictingthe
MIL-STD-105D Sampling Procedures and Tables for In-
failure of a product or service to perform its intended function
spection by Attributes
in use. Since this latter connotation is often unintended, the
2.3 Other Document:
term nonconformity is preferred in full consensus standards.
The selection of any sample plan is independent of whether the
term defect or nonconformity is appropriate.
This practice is under the jurisdiction of ASTM Committee D09 on Electrical
and Electronic Insulating Materials and is the direct responsibility of Subcommittee
The term defect may be appropriate for specifications mutually
D09.94 on Editorial.
Current edition approved Sept. 10, 2000. Published December 2000. Originally agreed upon by a producer and a user where specific use conditions are
published as D 3636 – 77. Last previous edition D 3636 – 99.
Annual Book of ASTM Standards, Vol 15.05.
Available from the U.S. Government Printing Office, Superintendent of
Available from American National Standards Institute, 11 W. 42nd St., 13th
Documents, 732 North Capitol Street, NW, Mail Stop: SDE, Washington, D.C.
Floor, New York, NY 10036 or American Society for Quality Control, 310 W.
20401.
Wisconsin Ave., Milwaukee, WI 53203.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D3636
clearly understood. Even in these cases however, use the term defect
3.1.16.1 Discussion—This standard uses only lot sample
with caution and consider substituting the term nonconformity.
sizes and not lot sizes since the discriminatory power of any
For additional comments, seeANSI/ASQCA2-1987 that also states:
sampling plan is independent essentially of the size of the lot.
“When a quality characteristic of a product or service is “evaluated” in
The sample size selected by the user for a given acceptable
terms of conformance to specification requirements, the use of the term
quality level (AQL) is optional depending upon the degree of
nonconformity is appropriate.”
protection desired by the user against the acceptance of
3.1.5 group AQL—theAQL assigned to a group of material
nonconforming lots.
properties.
3.1.17 test measurement, n—a quantitative expression of
3.1.5.1 Discussion—See 5.2 for additional information
one value determined for a property of interest by a single
about the meaning of AQL.
application of a specified test procedure.
3.1.6 lot, n—an entity of electrical insulating material or
3.1.18 test result, n—the value that expresses the level of a
product which, insofar as is practicable, consists of a single
property of the test unit.
type, grade, class, size, or composition that was manufactured
3.1.18.1 Discussion—A test result may sometimes be a
under essentially the same conditions and is available to the
single test measurement but usually a test result is computed
user for sampling at one time.
from several test measurements.
3.1.7 lot number, n—the number used by a producer to
3.1.19 test specimen, n—a portion of a test unit upon which
identify an entity of electrical insulating material or product.
one or more test measurements are made.
3.1.8 major property, n—a quantitatively measurable char-
3.1.20 test unit, n—a fraction of a unit of product from
acteristic which, if not met, is likely to seriously impair the
which one or more test specimens are taken for each property.
performance of a material or product for the intended use.
3.1.20.1 Discussion—If the unit of product is of insufficient
3.1.8.1 Discussion—In some situations, specification re-
size to meet the requirements of a testing method: (1) sample
quirements coincide with customer usage requirements. In
adjacent units of product and aggregate units of product for the
other situations, they may not coincide, being either more or
test unit or, (2) obtain a test unit of sufficient size, and
less stringent. More stringent sampling (for example, smaller
representative of the unit of product, from the producer.
AQLvalues)isusuallyusedformeasurementofcharacteristics
3.1.21 unit of product, n—an entity of electrical insulating
that are considered important. The selection of sampling plans
materialorproductforinspectiontodetermineitsclassification
is independent of whether the term defect or nonconformity is
as conforming or non-conforming.
appropriate.
3.1.21.1 Discussion—Aunit of product is established by the
3.1.9 minor property, n—a characteristic which, if not met,
user and may or may not be the same as a unit of purchase,
is not likely to materially reduce the performance of a material
supply, production, or shipment. Some examples of a unit of
or product for the intended use.
product are:
3.1.9.1 Discussion—In some situations, specification re-
Bag Case Reel
quirements coincide with customer usage requirements. In
Barrel Container Roll
Bin Cop Sheet
other situations, they may not coincide, being either more or
Bobbin Drum Skid
less stringent. More stringent sampling (for example, smaller
Box Length Spool
AQLvalues)isusuallyusedformeasurementofcharacteristics
Bundle Pad Tank
Car Pail Tank compartment
that are considered important. The selection of sampling plans
Carton Pallet Truckload
is independent of whether the term defect or nonconformity is
4. Summary of Practice
appropriate.
3.1.10 nonconforming unit, n—a unit of product containing
4.1 Instructions are given for obtaining a sample from
at least one nonconformity.
which specimens are then taken for testing. The test data are
3.1.11 nonconformities per hundred units, n— a calculated
compared to the material specification and a judgement is then
ratio of nonconforming units to the number of units inspected,
made as to whether the material meets the requirements of said
the quotient being multiplied by 100 (See 3.1.13.)
material specification.
3.1.12 nonconformity, n—a departure of a quality charac-
4.2 This practice has been modeled after MIL-STD105D.
teristic from its intended level or state that occurs with a
5. Procedure
severity sufficient to cause a test result not to meet a specifi-
cation requirement.
5.1 General Considerations:
3.1.13 percent nonconforming, n—a calculated ratio of 5.1.1 Assemble the lot of electrical insulating material so
nonconforming units to the number of units inspected, the
that a lot sample may be obtained in a manner that will
quotient being multiplied by 100. minimize bias in the selection of the units of product that will
3.1.14 rejection number, n—the minimum number of non- be inspected. A scheme that offers a good chance of minimiz-
conformitiesforagivenAQLandsamplesize(lot-samplesize) ing bias is the assignment of numbers to each unit of product
which will subject a lot to rejection.
and then using a table of random numbers to select those units
3.1.15 sample, n—one or more units of product taken from of product from which test units are taken.
a lot without regard to the quality of the unit. (Also often 5.1.2 For a lot of electrical insulating material which is in
termed lot sample). bulk form (for example, a tank car of powdered resin) take the
3.1.16 sample size, n—the number of units of product taken lot sample from the unit of product in accordance with Practice
to make up the sample. E 300.
D3636
5.1.3 Take the material to be removed from any unit of 5.2.2 When a user designates some specific value of AQL
product in a random manner. It will sometimes be impracti- for a single nonconformity, it indicates that the user’s accep-
cabletomeetthisrequirement(forexample,inthecaseoflong tance sampling plan will accept the great majority of the lots
lengths of material wound onto rolls or large, thick, heavy submitted by the producer if the process average level of
sheets packed on pallets or skids). In such situations economy percent nonconforming in the lots is no greater than the
will dictate the removal of material from the end of a roll, or designated value ofAQL. The preceding statement is also true
the top of a pile, etc. in which cases the selection cannot be for a group AQL value designated for a group of nonconfor-
described as “random.” mities.
5.1.4 Take the necessary amount of material from the test 5.2.2.1 The sampling plans of this standard are so arranged
unitsoastomeetthespecimenrequirementsofthevarioustest thattheprobabilityofacceptance,atthedesignatedAQLvalue,
methods that will be used to evaluate the material. depends upon the sample size. For a givenAQL, the probabil-
5.1.5 Refer to the material specification for the allowable ityofacceptancewillbegenerallyhigherforlargesamplesizes
maximum elapsed time between the assembly of the lot for than for small sample sizes. The AQL alone does not describe
inspection and the disposition of the lot. If the material the user protection for individual lots, but more directly relates
specification (or other pertinent document) does not cover this to what a user might expect from a series of lots. Refer to the
matter, the maximum allowable time is 30 calendar days. operating characteristic curve to determine what protection the
5.1.6 Exercise care to protect the electrical insulating mate- user will have for a specific AQL.
rial contained in the test unit from which specimens are to be 5.2.3 The designation of an AQL shall not imply that a
prepared. This protection may take the form of packaging in producerhastherighttoknowinglysupplyanynonconforming
metal foil or glass containers so as to prevent or minimize unit of product.
contamination of the material from the effects of the environ- 5.2.4 The values of AQL listed in the accompanying tables
menttowhichsuchmaterialissubjectedbetweensamplingand (see Section 8) are known as preferred AQL’s. If any AQL is
testing. designated other than a preferred AQL, these tables are not
5.1.7 Test units assembled as described above shall be applicable.
deemed to be representative of the lot of material being 5.3 Sampling Plan Selection:
inspected. Disposition of the lot, or portions thereof will be 5.3.1 Use the designated AQL and the sample size code
based upon the data generated from these test units unless letter from Table 1 to select a sampling plan from Tables 2-22.
otherwise agreed upon between the user and the producer. When no sampling plan is available for a given combination of
5.2 Establishing Acceptable Quality Levels: AQL and code letter, the table directs the user to a different
5.2.1 Acceptable quality levels (AQL’s) for each critical, code letter. Use the sample size given by the new code letter,
major, and minor property shall be as mutually agreed upon by not the original code letter.
the producer and the user. Group AQL’s for given groups of 5.3.1.1 This procedure may lead to different sample sizes
properties may likewise be established. These AQL’s may be for different classes of nonconformities. In such cases the user
disclosedinapurchaseorder,materialspecification,orinsome of the electrical insulating material may designate and autho-
other document. This standard is not intended to impose limits rize, for all classes of nonconformities, the selection and use of
upon the risks acceptable to either the user or the producer. thecodelettercorrespondingtothelargestsamplesizederived.
TABLE 1 Sample Size Code Letters (See 5.4)
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.