ASTM D6518-06

Standard Practice for Bias Testing a Mechanical Coal Sampling System

SCOPE
1.1 This practice presents sample collection and statistical evaluation procedures for testing mechanical sampling systems, subsystems, and individual system components for bias. It is the responsibility of the user of this practice to select the appropriate procedure for a specific sampling situation.
1.2 This practice does not purport to define an absolute bias. Bias defined by this practice is the difference between the population mean of the mechanical sampler test results and the accepted reference value.
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-Oct-2006
• ICS: 73.040 - Coals
• Technical Committee: D05 - Coal and Coke
• Drafting Committee: D05.23 - Sampling

Relations

• Replaces: ASTM D6518-03a - Standard Practice for Bias Testing a Mechanical Coal Sampling System
• Effective Date: 01-Nov-2006
• Replaced By: ASTM D6518-06e1 - Standard Practice for Bias Testing a Mechanical Coal Sampling System
• Effective Date: 01-Nov-2006
• Referred By: ASTM D7430/D7430M-22 - Standard Practice for Mechanical Sampling of Coal
• Effective Date: 01-Nov-2006
• Referred By: ASTM D6543-20e1 - Standard Guide to the Evaluation of Measurements Made by Online Coal Analyzers
• Effective Date: 01-Nov-2006

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D 6518 – 06
Standard Practice for
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Bias Testing a Mechanical Coal Sampling System
This standard is issued under the fixed designation D 6518; 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 E 691 Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method
1.1 This practice presents sample collection and statistical
evaluation procedures for testing mechanical sampling sys-
3. Terminology
tems, subsystems, and individual system components for bias.
3.1 Definitions—For additional definitions of terms used in
It is the responsibility of the user of this practice to select the
this practice refer to Terminologies D 121 and E 456.
appropriate procedure for a specific sampling situation.
3.2 Definitions of Terms Specific to This Standard:
1.2 Thispracticedoes not purport to define an absolutebias.
3.2.1 bias, n—the difference between the population mean
Bias defined by this practice is the difference between the
of the mechanical sampler test results and the accepted
population mean of the mechanical sampler test results and the
reference value.
accepted reference value.
3.2.2 confidence interval, n—a numeric interval with a
1.3 This standard does not purport to address all of the
lower limit and a higher limit within which the true parameter
safety concerns, if any, associated with its use. It is the
value is estimated to fall. The confidence interval percentage
responsibility of the user of this standard to establish appro-
indicates the percentage of time the true value will fall within
priate safety and health practices and determine the applica-
the interval if the procedure is continuously repeated.
bility of regulatory limitations prior to use.
3.2.3 correlation, n—a measure of the linear dependence
2. Referenced Documents between paired system and reference measurements. Correla-
2
tion frequently is expressed by the correlation coefficient,
2.1 ASTM Standards:
which can take a value from minus one (perfect negative linear
D 121 Terminology of Coal and Coke
relationship) to plus one (perfect positive linear relationship).
D 2013 Practice for Preparing Coal Samples for Analysis
3.2.4 delimitation error, n—a material error that occurs
D 2234/D 2234M Practice for Collection of a GrossSample
when all the elements in a cross section of a coal stream do not
of Coal
haveanequalprobabilityofbeingintercepted(captured)bythe
D 4621 Guide for Quality Management in an Organization
sampler cutter during increment collection.
That Samples or Tests Coal and Coke
3.2.5 ellipsoidal region, n—an area that is formed by plane
D 4702 Practice for Quality Management of Mechanical
sections of ellipses that are defined by the values selected for
Coal Sampling Systems
the largest tolerable bias of each coal characteristic used in the
E 105 Practice for Probability Sampling Of Materials
bias test. The region will be used to determine if the system is
E 122 Practice for Calculating Sample Size to Estimate,
biased.
With a Specified Tolerable Error, the Average for a
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3.2.6 Hotelling’s T test, n—a statistical test that is used to
Characteristic of a Lot or Process
evaluate multivariate data. It is the multivariate equivalent of
E 456 Terminology Relating to Quality and Statistics
the Student’s t-test.
3.2.7 largest tolerable bias (LTB), n—an interval whose
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This practice is under the jurisdiction of ASTM Committee D05 on Coal and upper and lower bounds represent the limits of an acceptable
Coke and is the direct responsibility of Subcommittee D05.23 on Sampling.
bias.
Current edition approved Nov. 1, 2006. Published November 2006. Originally
3.2.8 mechanical sampling system, n—a single machine or
approved in 2000. Last previous edition approved in 2003 as D 6518–03a.
2
series of interconnected machines whose purpose is to extract
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
mechanically, or process (divide and reduce), or a combination
Standards volume information, refer to the standard’s Document Summary page on
thereof, a sample of coal.
the ASTM website.
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D6518–06
3.2.9 paired data set, n—system and reference values ob- 4.2 This practice is based on matched-pair experimental
servedonsamplescollectedandcomparedfromthesamebatch designs. The practice describes two procedures of sample
of material. collectio
...