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ASTM D6607-00(2005)

(Practice)

Standard Practice for Inclusion of Precision Statement Variation in Specification Limits

Standard Practice for Inclusion of Precision Statement Variation in Specification Limits

SIGNIFICANCE AND USE
Each test method has a limited precision. Even if a test is performed as carefully and as correctly as possible on a material which is as homogeneous as can be obtained, the test will still vary from one to another. A widely used measure of the variation of the test results from a test method is the standard deviation (σ). In an ASTM standard test, the standard deviation of the test method can be found in the Precision and Bias statement for the test. The “Blue Book,” Form and Style for ASTM Standards, requires that all test methods include Precision and Bias statements. Practice C 670 and Practice C 802 provide guidance for determination of these values.
If the precision of a test method is low and the precision of the test has not been properly considered in a material specification, a uniform material with the right quality may still be rejected most of the time because of the wide variation of the test results. In order to have rational specification limits, the precision of the test used should be properly included in a specification.
This practice provides a guideline for proper inclusion of precision of the test method in a rational specification.
SCOPE
1.1 This practice covers a method of determining rational specification limits by inclusion of the precision of the test method used in the specification.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 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

Status
Historical
Publication Date
31-May-2005
ICS
19.020 - Test conditions and procedures in general
Technical Committee
D04 - Road and Paving Materials
Drafting Committee
D04.94 - Statistical Procedures and Evaluation of Data
Current Stage
Ref Project

Relations

Replaces
ASTM D6607-00 - Standard Practice for Inclusion of Precision Statement Variation in Specification Limits
Effective Date
01-Jun-2005
Replaced By
ASTM D6607-00(2009) - Standard Practice for Inclusion of Precision Statement Variation in Specification Limits
Effective Date
01-Dec-2009
Referred By
ASTM C670-15 - Standard Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials
Effective Date
01-Jun-2005

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ASTM D6607-00(2005) - Standard Practice for Inclusion of Precision Statement Variation in Specification LimitsASTM D6607-00(2005) - Standard Practice for Inclusion of Precision Statement Variation in Specification Limits
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ASTM D6607-00(2005) - Standard Practice for Inclusion of Precision Statement Variation in Specification Limits
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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.
Designation: D6607 – 00 (Reapproved 2005)
Standard Practice for
Inclusion of Precision Statement Variation in Specification
1
Limits
This standard is issued under the fixed designation D6607; 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 Acceptance—Quality Assurance, Federal Highway Ad-
3
ministration, May 1993
1.1 This practice covers a method of determining rational
specification limits by inclusion of the precision of the test
3. Terminology
method used in the specification.
3.1 For definitions of terms used in this practice, consult
1.2 The values stated in SI units are to be regarded as the
Practice E177.
standard. The values given in parentheses are for information
only.
4. Significance and Use
1.3 This standard does not purport to address all of the
4.1 Each test method has a limited precision. Even if a test
safety concerns, if any, associated with its use. It is the
is performed as carefully and as correctly as possible on a
responsibility of the user of this standard to establish appro-
material which is as homogeneous as can be obtained, the test
priate safety and health practices and determine the applica-
will still vary from one to another. A widely used measure of
bility of regulatory limitations prior to use.
the variation of the test results from a test method is the
standard deviation (s). In anASTM standard test, the standard
2. Referenced Documents
2
deviation of the test method can be found in the Precision and
2.1 ASTM Standards:
Bias statement for the test. The “Blue Book,” Form and Style
C670 Practice for Preparing Precision and Bias Statements
for ASTM Standards, requires that all test methods include
for Test Methods for Construction Materials
Precision and Bias statements. Practice C670 and Practice
C802 Practice for Conducting an Interlaboratory Test Pro-
C802 provide guidance for determination of these values.
gram to Determine the Precision of Test Methods for
4.2 If the precision of a test method is low and the precision
Construction Materials
of the test has not been properly considered in a material
D2172 Test Methods for Quantitative Extraction of Bitu-
specification,auniformmaterialwiththerightqualitymaystill
men From Bituminous Paving Mixtures
be rejected most of the time because of the wide variation of
D2726 Test Method for Bulk Specific Gravity and Density
thetestresults.Inordertohaverationalspecificationlimits,the
of Non-Absorptive Compacted Bituminous Mixtures
precision of the test used should be properly included in a
E177 Practice for Use of the Terms Precision and Bias in
specification.
ASTM Test Methods
4.3 This practice provides a guideline for proper inclusion
2.2 Federal Highway Administration Report:
of precision of the test method in a rational specification.
FHWA Report HI-93–047 Materials Control and
5. Procedure
1
5.1 Determine the effective standard deviation (s )ofthe
This guide is under the jurisdiction of Committee D04 on Road and Paving X
Materials and is the direct responsibility of Subcommittee D04.94 on Statistical test results due to the combined effects of materials variation
Procedures and Evaluation of Data.
and test variation using Eq 1:
Current edition approved June 1, 2005. Published June 2005. Originally
2 2
approved in 2000. Last previous edition approved in 2000 as D6607 – 00. DOI:
s 5 ~s 1s ! (1)
X M T
10.1520/D6607-00R05.
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
3
Standards volume information, refer to the standard’s Document Summary page on Available from National Technical Information Service (NTIS), U.S. Depart-
the ASTM website. ment of Commerce, 5285 Port Royal Rd., Springfield, VA 22161.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1

---------------------- Page: 1 ----------------------
D6607 – 00 (2005)
µ – Z s # 3# µ 1 Z s (3)
where: a/2 3 a/2 3
s = standard deviation of test property due to material
M
variation (see Note 1), and
where:
s = standarddeviationoftestpropertyduetotestmethod
T
µ = target property
(see Note 2).
Z = critical number of standard deviations for (1–a)
a/2
confidence interval. (See Table 1 for values of Z
NOTE 1—s istheexpectedstandarddeviationofthematerialproperty a /
M
2 for different specified confidence intervals.)
when the material is produced in a properly controlled process.Astandard
deviation which is representative of the acceptable variation of the
5.4 For a one-ended specification (with only a maximum or
mate
...

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Standard Practice for Inclusion of Precision Statement Variation in Specification Limits

SIGNIFICANCE AND USE
4.1 Each test method has a limited precision. Even if a test is performed as carefully and as correctly as possible on a material which is as homogeneous as can be obtained, the test will still vary from one to another. A widely used measure of the variation of the test results from a test method is the standard deviation (σ). In an ASTM standard test method, the standard deviation of the test method can be found in the Precision and Bias statement for the test. The “Blue Book,” Form and Style for ASTM Standards, requires that all test methods include Precision and Bias statements. Practices C670 and C802 provide guidance for determination of these values.  
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4.3 This practice provides a guideline for proper inclusion of precision of the test method in a rational specification.
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1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
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4.1 This guide describes the principal types of sampling designs and provides formulas for estimating population means and standard errors of the estimates. Practice E105 provides principles for designing probability sampling plans in relation to the objectives of study, costs, and practical constraints. Practice E122 aids in specifying the required sample size. Practice E141 describes conditions to ensure validity of the results of sampling. Further description of the designs and formulas in this guide, and beyond it, can be found in textbooks (1-10).3  
4.2 Sampling, both discrete and bulk, is a clerical and physical operation. It generally involves training enumerators and technicians to use maps, directories and stop watches so as to locate designated sampling units. Once a sampling unit is located at its address, discrete sampling and area sampling enumeration proceeds to a measurement. For bulk sampling, material is extracted into a composite.  
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4.5 The objective of sampling is often to estimate t...
SCOPE
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This guide identifies statistical procedures for use in developing new test methods or revising or evaluating existing test methods, or both. It also cites statistical procedures especially useful in the application of test methods. This standard recommends what approaches may be taken and indicates which standards may be used to perform such assessments.
SIGNIFICANCE AND USE
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FIG. 1 Sequence of Steps  
4.3 All ASTM test methods are required to include statements on precision and bias.3  
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5.1 Background—In a single laboratory, the limit of quantitation, LOQ, equal to ten times the standard deviation obtained under repeatability conditions extrapolated to zero concentration (s0) based on samples with close to zero concentrations has been recommended.3 A test result at this LOQ has an uncertainty of ±30 % at the 99 % confidence level.  
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SCOPE
1.1 This practice covers the use of standard regression techniques and data from an interlaboratory study to determine a lower quantitative limit for a test method. This determined lower limit represents the numerical limit at or above which the test results are considered to be quantitatively meaningful for commerce or regulatory activities by this practice. It is defined by this standard as the pooled limit of quantitation (PLOQ) for the test method.  
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This practice describes the techniques for planning, conducting, analyzing, and treating the results of an interlaboratory study (ILS) of a test method. The statistical techniques described in this practice provide adequate information for formulating the precision statement of a test method. This practice is also concerned exclusively with test methods which yield a single numerical figure as the test result, although the single figure may be the outcome of a calculation from a set of measurements. ASTM regulations require precision statements in all test methods in terms of repeatability and reproducibility and knowledge of the test method precision is useful in commerce and in technical work when comparing test results against standard values or between data sources.
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4.1 ASTM regulations require precision statements in all test methods in terms of repeatability and reproducibility. This practice may be used in obtaining the needed information as simply as possible. This information may then be used to prepare a precision statement in accordance with Practice E177. Knowledge of the test method precision is useful in commerce and in technical work when comparing test results against standard values (such as specification limits) or between data sources (different laboratories, instruments, etc.).  
4.1.1 When a test method is applied to a large number of portions of a material that are as nearly alike as possible, the test results obtained will not all have the same value. A measure of the degree of agreement among these test results describes the precision of the test method for that material. Numerical measures of the variability between such test results provide inverse measures of the precision of the test method. Greater variability implies smaller (that is, poorer) precision and larger imprecision.  
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4.2 The procedures presented in this practice consist of three basic steps: planning the interlaboratory study, guiding the testing phase of the study, and analyzing the test result data.  
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SCOPE
1.1 This practice describes the techniques for planning, conducting, analyzing, and treating the results of an interlaboratory study (ILS) of a test method. The statistical techniques described in this practice provide adequate information for formulating the precision statement of a test method.  
1.2 This practice does not concern itself with the development of test methods but rather with gathering the information needed for a test method precision statement after the development stage has been successfully completed. The data obtained in the interlaboratory study may indicate, however, that further effort is needed to improve the test method.  
1.3 Since the primary purpose of this practice is the development of the information needed for a precision statement, the experimental design in this practice may not be optimum for evaluating materials, apparatus, or individual laboratories.  
1.4 Field of Application—This practice is concerned exclusively with test methods which yield a single numerical figure as the test result, although the single figure may be the outcome of a calculation from a set of measurements.  
1.4.1 This practice ...

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Standard Test Method for Determination of the Accelerated Hydrogen Sulfide Breakthrough Capacity of Granular and Pelletized Activated Carbon

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5.1 This method compares the performance of granular or pelletized activated carbons used in odor control applications, such as sewage treatment plants, pump stations, etc. The method determines the relative breakthrough performance of activated carbon for removing hydrogen sulfide from a humidified gas stream. Other organic contaminants present in field operations may affect the H2S breakthrough capacity of the carbon; these are not addressed by this test. This test does not simulate actual conditions encountered in an odor control application, and is therefore meant only to compare the hydrogen sulfide breakthrough capacities of different carbons under the conditions of the laboratory test.  
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SCOPE
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1.4 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.

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