ASTM D7372-12

Standard Guide for Analysis and Interpretation of Proficiency Test Program Results

SIGNIFICANCE AND USE
This guide can be used to evaluate the performance of a laboratory or group of laboratories participating in an interlaboratory proficiency test (PT) program involving petroleum and petroleum products.
Data accrued, using the techniques included in this guide, provide the ability to monitor analytical measurement system precision and bias. These data are useful for updating standard test methods, as well as for indicating areas of potential measurement system improvement for action by the laboratory. This guide serves both the individual participating laboratory and the responsible standards development group as follows:
5.2.1 Tools and Approaches for Participating Laboratories.
Administrative Reviews
Flagged Data and Investigations
Data Normality Checks
Histograms
Bias (Deviation from Mean)
Z-Scores
TPI (Industry)
PTP and Site Precision Comparisons
5.2.2 Tools and Approaches for Responsible Standards Development Groups.
TPI and precision trends
Bias via box & whisker plots
Normality evaluations
Relative standard deviations
Uncontrolled variables
Reference is made in this guide to the ASTM International Interlaboratory Cross-Check Program (ILCP) on Petroleum Products and Lubricants. Program reports containing similarly displayed results and statistical treatments may be available in other PT programs. Appendix X2 summarizes the statistical tools referenced in this guide and Appendix X3 is a collection of examples covering many of the approaches described in this guide.
SCOPE
1.1 This guide covers the analysis and interpretation of proficiency test (PT) program results. For participants in interlaboratory proficiency test (PT) (or crosscheck, check scheme, etc.) programs, this guide describes procedures for assessing participants' results relative to the PT program results and potentially improving the laboratory's testing performance based on the assessment findings and insights. For the committees responsible for the test methods included in interlaboratory proficiency testing programs, this guide describes procedures for assessing industry's ability to perform test methods and for potentially identifying needs for method improvement.
1.2 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: 14-Apr-2012
• ICS: 11.100.01 - Laboratory medicine in general
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.94 - Coordinating Subcommittee on Quality Assurance and Statistics

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:D7372 −12 An American National Standard
Standard Guide for
Analysis and Interpretation of Proficiency Test Program
1
Results
This standard is issued under the fixed designation D7372; 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* Used and Unused Lubricating Oils and Base Oils by
Inductively Coupled Plasma Atomic Emission Spectrom-
1.1 This guide covers the analysis and interpretation of
etry (ICP-AES)
proficiency test (PT) program results. For participants in
D5453 Test Method for Determination of Total Sulfur in
interlaboratory proficiency test (PT) (or crosscheck, check
Light Hydrocarbons, Spark Ignition Engine Fuel, Diesel
scheme, etc.) programs, this guide describes procedures for
Engine Fuel, and Engine Oil by Ultraviolet Fluorescence
assessing participants’ results relative to the PT program
D6259 Practice for Determination of a Pooled Limit of
results and potentially improving the laboratory’s testing
Quantitation
performancebasedontheassessmentfindingsandinsights.For
D6299 Practice for Applying Statistical Quality Assurance
the committees responsible for the test methods included in
and Control Charting Techniques to Evaluate Analytical
interlaboratory proficiency testing programs, this guide de-
Measurement System Performance
scribes procedures for assessing industry’s ability to perform
D6617 Practice for Laboratory Bias Detection Using Single
test methods and for potentially identifying needs for method
Test Result from Standard Material
improvement.
D6792 Practice for Quality System in Petroleum Products
1.2 This standard does not purport to address all of the
and Lubricants Testing Laboratories
safety concerns, if any, associated with its use. It is the
D7039 Test Method for Sulfur in Gasoline, Diesel Fuel, Jet
responsibility of the user of this standard to establish appro-
Fuel, Kerosine, Biodiesel, Biodiesel Blends, and
priate safety and health practices and determine the applica-
Gasoline-Ethanol Blends by Monochromatic Wavelength
bility of regulatory limitations prior to use.
Dispersive X-ray Fluorescence Spectrometry
E177 Practice for Use of the Terms Precision and Bias in
2. Referenced Documents
ASTM Test Methods
2
2.1 ASTM Standards:
E456 Terminology Relating to Quality and Statistics
D1266 Test Method for Sulfur in Petroleum Products (Lamp
E2655 Guide for Reporting Uncertainty of Test Results and
Method)
Use of the Term Measurement Uncertainty inASTM Test
D2622 Test Method for Sulfur in Petroleum Products by
Methods
Wavelength Dispersive X-ray Fluorescence Spectrometry
3. Terminology
D4294 Test Method for Sulfur in Petroleum and Petroleum
Products by Energy Dispersive X-ray Fluorescence Spec-
3.1 Definitions:
trometry
3.1.1 accuracy, n—closeness of agreement between an ob-
D4951 Test Method for Determination ofAdditive Elements
served value and an accepted reference value. E177, E456
in Lubricating Oils by Inductively Coupled Plasma
3.1.2 assignable cause, n—factor that contributes to varia-
Atomic Emission Spectrometry
tion and that is feasible to detect and identify. E456
D5185 Test Method for Multielement Determination of
3.1.3 bias, n—systematic error that contributes to the differ-
ence between a population mean of the measurements or test
results and an accepted reference or true value. E177, E456
1
This guide is under the jurisdiction of ASTM Committee D02 on Petroleum
Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcom- 3.1.4 control limits, n—limits on a control chart that are
mittee D02.94 on Coordinating Subcommittee on QualityAssurance and Statistics.
used as criteria for signaling the need for action or for judging
Current edition approved April 15, 2012. Published October 2012. Originally
whether a set of data does or does not indicate a state of
approved in 2007. Last previous edition approved in 2007 as D7372–07. DOI:
statistical control. E456
10.1520/D7372-12.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
3.1.5 in-statistical-control, adj—process, analytical mea-
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
surement system, or function that exhibits variations that can
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. only be attributable to common cause. D6299
*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
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D7372−12
3.1
...

This document is not anASTM standard and is intended only to provide the user of anASTM 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.
An American National Standard
Designation:D7372–07 Designation: D7372 – 12
Standard Guide for
Analysis and Interpretation of Proficiency Test Program
1
Results
This standard is issued under the fixed designation D7372; 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 (ϵ) indicates an editorial change since the last revision or reapproval.
1. Scope*
1.1 This guide covers the analysis and interpretation of proficiency test (PT) program results. For participants in interlaboratory
proficiency test (PT) (or crosscheck, check scheme, etc.) programs, this guide describes procedures for assessing participants’
results relative to the PT program results and potentially improving the laboratory’s testing performance based on the assessment
findingsandinsights(see6.1).insights.Forthecommitteesresponsibleforthetestmethodsincludedininterlaboratoryproficiency
testing programs, this guide describes procedures for assessing the industry’s ability to perform test methods,methods and for
potentially identifying needs for test method improvement (see 6.2). improvement.
1.2 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.
2. Referenced Documents
2
2.1 ASTM Standards: ASTM Standards:
D1266 Test Method for Sulfur in Petroleum Products (Lamp Method)
D2622 Test Method for Sulfur in Petroleum Products by Wavelength Dispersive X-ray Fluorescence Spectrometry
D4294 Test Method for Sulfur in Petroleum and Petroleum Products by Energy Dispersive X-ray Fluorescence Spectrometry
D4951 Test Method for Determination of Additive Elements in Lubricating Oils by Inductively Coupled Plasma Atomic
Emission Spectrometry
D5185 Test Method for Determination of Additive Elements, Wear Metals, and Contaminants in Used Lubricating Oils and
Determination of Selected Elements in Base Oils by Inductively Coupled PlasmaAtomic Emission Spectrometry (ICP-AES)
D5453 Test Method for Determination of Total Sulfur in Light Hydrocarbons, Spark Ignition Engine Fuel, Diesel Engine Fuel,
and Engine Oil by Ultraviolet Fluorescence
D6259 Practice for Determination of a Pooled Limit of Quantitation
D6299 Practice for Applying Statistical Quality Assurance and Control Charting Techniques to Evaluate Analytical
Measurement System Performance
D6617 Practice for Laboratory Bias Detection Using Single Test Result from Standard Material
D6792 Practice for Quality System in Petroleum Products and Lubricants Testing Laboratories
D7039 Test Method for Sulfur in Gasoline and Diesel Fuel by Monochromatic Wavelength Dispersive X-ray Fluorescence
Spectrometry
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E456 Terminology Relating to Quality and Statistics Terminology Relating to Quality and Statistics
E2655 Guide for Reporting Uncertainty ofTest Results and Use of theTerm Measurement Uncertainty inASTMTest Methods
3. Terminology
3.1 Definitions:
3.1.1 accuracy, n—closeness of agreement between an observed value and an accepted reference value. E177, E456
3.1.2 assignable cause, n—factor that contributes to variation and that is feasible to detect and identify. E456
3.1.3 bias, n—systematic error that contributes to the difference between a population mean of the measurements or test results
1
This guide is under the jurisdiction of ASTM Committee D02 on Petroleum Products and Lubricants and is the direct responsibility of Subcommittee D02.94 on
Coordinating Subcommittee on Quality Assurance and Statistics.
Current edition approved July 1, 2007. Published July 2007. DOI: 10.1520/D7372-07.
Current edition approved April 15, 2012. Published October 2012. Originally approved in 2007. Last previous edition approved in 2007 as D7372–07. DOI:
10.1520/D7372-12.
2
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*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.
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