ASTM G117-02
(Guide)Standard Guide for Calculating and Reporting Measures of Precision Using Data from Interlaboratory Wear or Erosion Tests
Standard Guide for Calculating and Reporting Measures of Precision Using Data from Interlaboratory Wear or Erosion Tests
SCOPE
1.1 This guide offers direction on the handling of data from interlaboratory tests for wear or erosion. It describes a format for entering data and for subsequently reporting results on measures of precision in a Committee G02 standard. It indicates methods for calculation of the needed statistical quantities.
1.2 The document offers guidance based on a Committee G02 consensus, and exists for the purpose of emphasizing the need to use established statistical practices, and to introduce more uniformity in reporting interlaboratory test results in Committee G02 standards.
1.3 An example of how the methods described in this guide may be applied is available in personal computer format (DOS type system) on floppy disk as a spreadsheet (LOTUS, rel. 4) file. The purpose is to facilitate use of the methods in this guide. The example file contains all needed equations in the recommended format and can be edited to accept new data. ASTM Headquarters or the Chairman of G02 should be contacted for a copy of that computer file. The user must have spreadsheet software (for example, LOTUS or compatible) available.
1.4 The methods used in this document are consistent with Practices E 691 and E 177, and with the PC version of Practice E 691.
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Standards Content (Sample)
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Designation:G117–02
Standard Guide for
Calculating and Reporting Measures of Precision Using
1
Data from Interlaboratory Wear or Erosion Tests
This standard is issued under the fixed designation G117; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope G76 Practice for Conducting Erosion Tests by Solid Par-
4
ticle Impingement Using Gas Jets
1.1 This guide offers direction on the handling of data from
G77 Test Method for Ranking Resistance of Materials to
interlaboratory tests for wear or erosion. It describes a format
4
Sliding Wear Using Block-on-Ring Wear Test
for entering data and for subsequently reporting results on
measures of precision in a Committee G02 standard. It indi-
3. Summary of Guide
cates methods for calculation of the needed statistical quanti-
3.1 Use of this guide in preparation of interlaboratory test
ties.
results for inclusion in G02 standards involves a sequence of
1.2 The document offers guidance based on a Committee
steps. First the raw data from the individual laboratories are
G02 consensus, and exists for the purpose of emphasizing the
entered into a table of any suitable form that permits calcula-
need to use established statistical practices, and to introduce
tion of average values and standard deviations for each
more uniformity in reporting interlaboratory test results in
laboratory. Then those two measures are entered, for each
Committee G02 standards.
laboratory, into a table such as that shown in Fig. 1. Then the
1.3 An example of how the methods described in this guide
steps described in this guide are carried out, leading to
may be applied is available in personal computer format (DOS
calculation of the precision measures that are to be used in the
type system) on floppy disk as a spreadsheet (LOTUS, rel. 4)
standard being prepared.
file. The purpose is to facilitate use of the methods in this
guide. The example file contains all needed equations in the
4. Significance and Use
recommended format and can be edited to accept new data.
4.1 Thisguideisintendedtoassistindevelopingstatements
ASTM Headquarters or the Chairman of G02 should be
ofprecisionandsupportingdatathatwillbeusedinCommittee
contacted for a copy of that computer file. The user must have
G02 standards. The methods and approach are drawn from
spreadsheet software (for example, LOTUS or compatible)
Practice E177 and E691. It was felt that preparation of this
available.
guide and its use in Committee G02 would lead to appropriate
1.4 The methods used in this document are consistent with
statistical analyses and more uniformity in G02 standards
PracticesE691andE177,andwiththePCversionofPractice
regarding reporting of interlaboratory results and precision.
2
E691.
The guide is not meant to substitute for possible use of
Practices E177 or E691 in developing committee standards.
2. Referenced Documents
2.1 ASTM Standards:
5. Procedure
E177 Practice for Use of the Terms Precision and Bias in
5.1 An example of interlaboratory data analyzed and pre-
3
ASTM Test Methods
sentedintherecommendedformatisshowninFig.1.Thedata
E691 Practice for Conducting an Interlaboratory Study to
3 were obtained from an interlaboratory series of solid particle
Determine the Precision of a Test Method
erosiontestscarriedoutinconnectionwithPracticeG76.This
G65 Test Method for Measuring Abrasion Using the Dry
4 tableformatcanbeusedwitheitherPCspreadsheetcalculation
Sand/Rubber Wheel Apparatus
or hand calculation.
5.2 Datatabulationandcalculationcanbecarriedoutbyuse
1
This guide is under the jurisdiction of ASTM Committee G02 on Wear and of a PC and numeric spreadsheet software (for example,
Erosion and is the direct responsibility of Subcommittee G02.20 on Computeriza-
LOTUS), as described in Table 1, or by any other appropriate
tion in Wear and Erosion.
means such as hand calculation (Table 2). The formulae were
Current edition approved Nov. 10, 2002. Published February 2003 Originally
obtained from Practices E177 or E691 or from statistical
approved in 1993. Last previous edition approved in 1998 as G117 – 98.
2
Available from ASTM Headquarters. Order PCN 12-506910-34. analysis texts. Formulae that are used for calculation are given
3
Annual Book of ASTM Standards, Vol 14.02.
4
Annual Book of ASTM Standards, Vol 03.02.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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G117–02
NOTE 1—Column and row labels A, B,.and1,2,.arenot required.
FIG. 1 Example of Recommended Format for Data Analysis
TABLE 1 Formulae
...
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