ASTM D4821-14
(Guide)Standard Guide for Carbon Black—Validation of Test Method Precision and Bias
Standard Guide for Carbon Black—Validation of Test Method Precision and Bias
SIGNIFICANCE AND USE
4.1 This guide recommends the use of statistical x-charts to graphically monitor test data determined for the ASTM reference blacks for those test methods given in Section 2. All laboratories are encouraged to utilize statistical x-charts and ASTM reference blacks because this enables a comparison of testing precision within and between laboratories. The guide describes practices for the use of repeatability and reproducibility limits and x-charts.
4.2 In addition to the calibration of a test method by physicochemical means, a statistical method for achieving calibration of a test method is presented (that is, normalization).
4.3 Poor test precision can be the result of poor repeatability or poor reproducibility or both. Causes may include inadequate operator training, improperly maintained equipment or laboratory environment, variation in sample preparation or analysis techniques, the lack of calibration or standardization of instrumentation, worn-out apparatus, reagents that do not meet specifications, different sources of instrumentation or equipment, and material heterogeneity. The sum of all sources of testing error is unique for an individual laboratory.
4.4 Precision data for ASTM Reference Blacks are found in Tables 1-3. These include standard reference blacks (SRB’s) Series 8, HT and INR Iodine Standards. The HT or INR Iodine standards are recommended for monitoring iodine testing.
Note 1: Preferred precision values are bolded in Tables 1-3.
SCOPE
1.1 This guide covers procedures for using the ASTM Standard Reference Blacks2 (SRBs) and the HT and INR Iodine Number Standards to continuously monitor the precision of those carbon black test methods for which reference values have been established. It also offers guidelines for troubleshooting various test methods.
1.2 This guide establishes procedures for the use of x-charts to continuously monitor those tests listed in Section 2 for within-lab precision (repeatability) and between-lab accuracy (reproducibility).
1.3 This guide provides a statistical procedure for improving test reproducibility when a laboratory cannot physically calibrate its apparatus to obtain the reference values of the ASTM reference blacks, within the ranges given in this guide.
General Information
Relations
Buy Standard
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: D4821 − 14
StandardGuide for
Carbon Black—Validation of Test Method Precision and
1
Bias
This standard is issued under the fixed designation D4821; 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 D3324 Practice for Carbon Black—Improving Test Repro-
ducibilityUsingASTMStandardReferenceBlacks(With-
1.1 This guide covers procedures for using the ASTM
4
2 drawn 2002)
Standard Reference Blacks (SRBs) and the HT and INR
D3493 Test Method for Carbon Black—Oil Absorption
Iodine Number Standards to continuously monitor the preci-
Number of Compressed Sample (COAN)
sion of those carbon black test methods for which reference
D6556 Test Method for Carbon Black—Total and External
values have been established. It also offers guidelines for
Surface Area by Nitrogen Adsorption
troubleshooting various test methods.
E177 Practice for Use of the Terms Precision and Bias in
1.2 This guide establishes procedures for the use of x-charts
ASTM Test Methods
to continuously monitor those tests listed in Section 2 for
E2282 Guide for Defining the Test Result of a Test Method
within-lab precision (repeatability) and between-lab accuracy
E2586 Practice for Calculating and Using Basic Statistics
(reproducibility).
3. Terminology
1.3 This guide provides a statistical procedure for improv-
3.1 Definitions:
ing test reproducibility when a laboratory cannot physically
3.1.1 accepted reference value, n—a value that serves as an
calibrate its apparatus to obtain the reference values of the
agreed-upon reference for comparison, and which is derived
ASTM reference blacks, within the ranges given in this guide.
as: (1) a theoretical or established value, based on scientific
principles, (2) an assigned or certified value, based on experi-
2. Referenced Documents
mental work of some national or international organization, or
3
2.1 ASTM Standards:
(3) a consensus or certified value, based on collaborative
D1510 Test Method for Carbon Black—Iodine Adsorption
experimental work under the auspices of a scientific or
Number
engineering group.
D1513 Test Method for Carbon Black, Pelleted—Pour Den-
3.1.1.1 Discussion—A national or international
sity
organization, referred to in (2), generally maintains measure-
D1765 Classification System for Carbon Blacks Used in
ment standards to which the reference values obtained are
Rubber Products
traceable. E177
D2414 Test Method for Carbon Black—Oil Absorption
3.1.2 accuracy, n—the closeness of agreement between a
Number (OAN)
test result and an accepted reference value.
D3265 Test Method for Carbon Black—Tint Strength
3.1.2.1 Discussion—The term accuracy, when applied to a
set of test results, involves a combination of a random
component and of a common systematic error or bias
1
This guide is under the jurisdiction ofASTM Committee D24 on Carbon Black
component. E177
and is the direct responsibility of Subcommittee D24.61 on Carbon Black Sampling
and Statistical Analysis. 3.1.3 ASTM reference blacks, n—a set of carbon blacks that
Current edition approved June 1, 2014. Published August 2014. Originally
span the useful range of the test method for which they are
ε1
approved in 1988. Last previous edition approved in 2007 as D4821 – 07 . DOI:
reference materials. D3324
10.1520/D4821-14.
2
Standard Reference Blacks are available from Laboratory Standards &
3.1.4 bias, n—the difference between the expectation of the
Technologies, Inc., 227 Somerset St., Borger, TX 79007.
test results and an accepted reference value.
3
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
4
Standards volume information, refer to the standard’s Document Summary page on The last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
D4821 − 14
3.1.4.1 Discussion—Bias is the total systematic error as expressed in terms of imprecision and computed as a standard
contrasted to random error. There may be one or more deviation of the test results. Less precision is reflected by a
systematic error components contributing to the bias. A larger larger standard deviation.
systematic difference from the accepted reference value is 3.1.13.3 Discussion—“Independent test results” means re-
reflected by a larger bias value. E177
sults obtained in a manner not influenced by any previous
result on the same or similar test object.
...
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.
´1
Designation: D4821 − 07 D4821 − 14
Standard Guide for
Carbon Black—Validation of Test Method Precision and
1
Bias
This standard is issued under the fixed designation D4821; 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
ε NOTE—Editorially corrected Footnote 3 and corresponding references in August 2011.
1. Scope
2
1.1 This guide covers a procedure procedures for using the ASTM Standard Reference Blacks (SRBs) and the HT and INR
Iodine Number Standards to continuously monitor the precision of those carbon black test methods for which standardreference
values have been established. It also offers guidelines for troubleshooting various test methods.
1.2 This guide establishes the x-chart control limits to be used when continuously monitoringprocedures for the use of x-charts
to continuously monitor those tests listed in Section 2. Alternatively, these control limits may be used as a basis for comparison
to testing precision computed within a laboratory. for within-lab precision (repeatability) and between-lab accuracy (reproduc-
ibility).
3
1.3 This guide uses statistical control chart methodology as discussed in MNL7 to determine if a laboratory’s test results differ
significantly from the accepted values of the SRBs.
1.3 This guide provides a statistical procedure for improving test reproducibility when a laboratory cannot physically calibrate
its apparatus to obtain the standardreference values of the ASTM SRBs, reference blacks, within the ranges given in the precision
statement of the test method.this guide.
1.5 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.6 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
3
2.1 ASTM Standards:
D1510 Test Method for Carbon Black—Iodine Adsorption Number
D1513 Test Method for Carbon Black, Pelleted—Pour Density
D1765 Classification System for Carbon Blacks Used in Rubber Products
D2414 Test Method for Carbon Black—Oil Absorption Number (OAN)
D3037D3265 Test Method for Carbon Black—Surface Area by Nitrogen AdsorptionBlack—Tint Strength (Withdrawn 1999)
D3191D3324 Test Methods for Carbon Black in SBR (Styrene-Butadiene Rubber)—Recipe and Evaluation ProceduresPractice
4
for Carbon Black—Improving Test Reproducibility Using ASTM Standard Reference Blacks (Withdrawn 2002)
D3192 Test Methods for Carbon Black Evaluation in NR (Natural Rubber)
D3265 Test Method for Carbon Black—Tint Strength
D3493 Test Method for Carbon Black—Oil Absorption Number of Compressed Sample (COAN)
D3765D6556 Test Method for Carbon Black—CTAB (Cetyltrimethylammonium Bromide)Black—Total and External Surface
Area by Nitrogen Adsorption (Withdrawn 2007)
1
This guide is under the jurisdiction of ASTM Committee D24 on Carbon Black and is the direct responsibility of Subcommittee D24.61 on Carbon Black Sampling and
Statistical Analysis.
Current edition approved Oct. 1, 2007June 1, 2014. Published November 2007August 2014. Originally approved in 1988. Last previous edition approved in 20062007
ε1
as D4821 – 06.D4821 – 07 . DOI: 10.1520/D4821-07E01. 10.1520/D4821-14.
2
Standard Reference Blacks are available from Laboratory Standards & Technologies, Inc., 227 Somerset St., Borger, TX 79007.
3
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.
4
The last approved version of this historical standard is referenced on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
D4821 − 14
5
D4820 Test Methods for Carbon Black—Surface Area by Multipoint B.E.T. Nitrogen Adsorption (Withdrawn 2000)
D5816E177 Test Methods for Carbon Black—External Surface Area by Multipoint Nitrogen AdsorptionPractice for Use of the
Terms Precision and Bias in ASTM Test Methods (Withdrawn 2000)
D6556E22
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.