ASTM B762-21
(Guide)Standard Guide of Variables Sampling of Metallic and Inorganic Coatings
Standard Guide of Variables Sampling of Metallic and Inorganic Coatings
SIGNIFICANCE AND USE
5.1 Sampling inspection permits the estimation of the overall quality of a group of product articles through the inspection of a relatively small number of product articles drawn from the group.
5.2 The specification of a sampling plan provides purchasers and sellers a means of identifying the minimum quality level that is considered to be satisfactory.
5.3 Because sampling plans yield estimates of the quality of a product, the results of the inspection are subject to error. Through the selection of a sampling plan, the potential error is known and controlled.
5.4 Sampling inspection is used when a decision must be made about what to do with a quantity of articles. This quantity may be a shipment from a supplier, articles that are ready for a subsequent manufacturing operation, or articles ready for shipment to a customer.
5.5 In sampling inspection, a relatively small number of articles (the sample) is selected randomly from a larger number of articles (the inspection lot); the sample is inspected for conformance to the requirements placed on the articles. Based on the results, a decision is made whether or not the lot conforms to the requirements.
5.6 Since only a portion of a production lot is inspected, the quality of the uninspected articles is not known. The possibility exists that some of the uninspected articles are nonconforming. Therefore, basic to any sampling inspection plan is the willingness of the buyer to accept lots that contain some nonconforming articles. The number of nonconforming articles in accepted lots is controlled by the size of the sample and the criteria of acceptance that are placed on the sample.
5.7 Acceptance sampling plans are used for the following reasons:
5.7.1 When the cost of inspection is high and the consequences of accepting a nonconforming article are not serious.
5.7.2 When 100 % inspection is fatiguing and boring and, therefore, likely to result in errors.
5.7.3 When inspection requires a destru...
SCOPE
1.1 This guide provides sampling plans that are intended for use in the inspection of metallic and inorganic coatings on products for the purpose of deciding whether submitted lots of coated products comply with the specifications applicable to the coating.
1.2 The sampling plans are variables plans. In plans of this type, several articles of product are drawn from a production lot. A characteristic of the coating on the drawn articles is measured. The values obtained are used to estimate the number of articles in the lot that do not conform to a numerical limit, for example a minimum thickness. The number is compared to a maximum allowable.
1.3 Variables plans can only be used when the characteristic of interest is measurable, the test method gives a numerical measure of the characteristic, and the specification places a numerical limit on the measured value. It is also necessary that the variation of the characteristic from article to article in a production 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, see X2.7) so that the values from article to article are comparable. If one or more of these conditions are not met, a variables plan cannot be used. Instead, an attributes plan must be used. These are given in Guide B602 and Guide B697.
1.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade ...
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This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: B762 − 21
Standard Guide of
1
Variables Sampling of Metallic and Inorganic Coatings
This standard is issued under the fixed designation B762; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
2
1.1 This guide provides sampling plans that are intended for 2.1 ASTM Standards:
use in the inspection of metallic and inorganic coatings on B602 Test Method for Attribute Sampling of Metallic and
products for the purpose of deciding whether submitted lots of Inorganic Coatings
coated products comply with the specifications applicable to B697 Guide for Selection of Sampling Plans for Inspection
the coating. of Electrodeposited Metallic and Inorganic Coatings
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2.2 ANSI Standards:
1.2 The sampling plans are variables plans. In plans of this
ANSI/ASQC Z1.9-1979 Sampling Procedures and Tables
type, several articles of product are drawn from a production
for Inspection by Variables for Percent Non-Conformance
lot. A characteristic of the coating on the drawn articles is
ANSI/ASQC Z1.4-1981 Sampling Procedures and Tables
measured.Thevaluesobtainedareusedtoestimatethenumber
for Inspection by Attributes
of articles in the lot that do not conform to a numerical limit,
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2.3 Military Standards:
for example a minimum thickness. The number is compared to
MIL-STD-105 Sampling Procedures and Tables for Inspec-
a maximum allowable.
tion by Attributes
1.3 Variables plans can only be used when the characteristic
MIL-STD-414 Sampling Procedures and Tables for Inspec-
of interest is measurable, the test method gives a numerical
tion by Variables for Percent Defective
measure of the characteristic, and the specification places a
3. Terminology
numerical limit on the measured value. It is also necessary that
the variation of the characteristic from article to article in a
3.1 destructive test, n—test that destroys the tested article or
production lot be normally distributed (see Appendix X2).
makes it nonconforming to a requirement.
Each article must be tested in the same way (for example,
3.2 inspection lot, n—collection of articles of the same kind
coating thickness must be measured at the same location, see
that is submitted to inspection for acceptance or rejection as a
X2.7) so that the values from article to article are comparable.
group.
If one or more of these conditions are not met, a variables plan
cannot be used. Instead, an attributes plan must be used. These 3.3 nondestructive test, n—test that neither destroys the
are given in Guide B602 and Guide B697. tested article nor makes it nonconforming to a requirement.
1.4 This standard does not purport to address all of the 3.4 sample, n—articles randomly selected from an inspec-
safety concerns, if any, associated with its use. It is the
tion lot whose quality is used to decide whether or not the
responsibility of the user of this standard to establish appro- inspection lot is of acceptable quality.
priate safety, health, and environmental practices and deter-
3.5 standard deviation, n—measure of dispersion equal to
mine the applicability of regulatory limitations prior to use.
the square root of the mean of the squares of the deviations
1.5 This international standard was developed in accor-
from the arithmetic mean of the distribution (see 9.2.6).
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the 4. Summary of Guide
Development of International Standards, Guides and Recom-
4.1 The plans in this guide provide the same protection as
mendations issued by the World Trade Organization Technical
the attributes plans inTables 1, 2, and 3 of Guide B602 and are
Barriers to Trade (TBT) Committee.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
1
This guide is under the jurisdiction ofASTM Committee B08 on Metallic and Standards volume information, refer to the standard’s Document Summary page on
Inorganic Coatings and is the direct responsibility of Subcommittee B08.10 on Test the ASTM website.
3
Methods. Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
Current edition approved Oct. 1, 2021. Published November 2021. Originally 4th Floor, New York, NY 10036, http://www.ansi.org.
4
approvedin1986.Lastpreviouseditionapprovedin2016asB762 – 90(2016).DOI: Available from Standardization Documen
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: B762 − 90 (Reapproved 2016) B762 − 21
Standard Test Method Guide of
1
Variables Sampling of Metallic and Inorganic Coatings
This standard is issued under the fixed designation B762; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method guide provides sampling plans that are intended for use in the inspection of metallic and inorganic coatings
on products for the purpose of deciding whether submitted lots of coated products comply with the specifications applicable to the
coating.
1.2 The sampling plans are variables plans. In plans of this type, several articles of product are drawn from a production lot. A
characteristic of the coating on the drawn articles is measured. The values obtained are used to estimate the number of articles in
the lot that do not conform to a numerical limit, for example a minimum thickness. The number is compared to a maximum
allowable.
1.3 Variables plans can only be used when the characteristic of interest is measurable, the test method gives a numerical measure
of the characteristic, and the specification places a numerical limit on the measured value. It is also necessary that the variation
of the characteristic from article to article in a production 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, see X2.7) so that the values from
article to article are comparable. If one or more of these conditions are not met, a variables plan cannot be used. Instead, an
attributes plan must be used. These are given in Test Method Guide B602 and Guide B697.
1.4 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2
2.1 ASTM Standards:
B602 Test Method for Attribute Sampling of Metallic and Inorganic Coatings
B697 Guide for Selection of Sampling Plans for Inspection of Electrodeposited Metallic and Inorganic Coatings
3
2.2 ANSI Standards:
ANSI/ASQC Z1.9-1979 Sampling Procedures and Tables for Inspection by Variables for Percent Non-Conformance
ANSI/ASQC Z1.4-1981 Sampling Procedures and Tables for Inspection by Attributes
1
This test method guide is under the jurisdiction of ASTM Committee B08 on Metallic and Inorganic Coatings and is the direct responsibility of Subcommittee B08.10
on Test Methods.
Current edition approved Nov. 1, 2016Oct. 1, 2021. Published November 2016November 2021. Originally approved in 1986. Last previous edition approved in 20102016
as B762 – 90 (2010).(2016). DOI: 10.1520/B0762-90R16.10.1520/B0762-21.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
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B762 − 21
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2.3 Military Standards:
MIL-STD-105 Sampling Procedures and Tables for Inspection by Attributes
MIL-STD-414 Sampling Procedures and Tables for Inspection by Variables for Percent Defective
3. Definitions Terminology
3.1 destructive test—test, n—test that destroys the tested article or makes it nonconforming to a requirement.
3.2 nondestructive test—test that neither destroys the tested article nor makes it nonconforming to a requirement.
3.2 inspection lot—lot, n—collection of articles of the same kind that is submitted to inspection for acceptance or rejection as a
group.
3.3 nondestructive t
...
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