ASTM D4821-20

Standard Guide for Carbon Black—Validation of Test Method Precision and Bias

SIGNIFICANCE AND USE
4.1 This guide provides insight into the environmental conditions required for operation of laboratories or to aid in the design of new laboratories that perform carbon black testing activities using those test methods that are under D24’s jurisdiction. This guide does not supersede any specific requirements a laboratory may choose to establish.  
4.2 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.  
4.3 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).  
4.4 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.  
4.5 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. (A) The iodine adsorption number of carbon black has been shown to decrease in value as the carbon black ages. Generally, the higher the surface area the faster the rate of change. Therefore, the target or mean values given in...
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 defines the environmental conditions that are required for laboratories that perform carbon black testing activities for those test methods under D24’s jurisdiction.  
1.3 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).  
1.4 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.  
1.5 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.

General Information

• Status: Published
• Publication Date: 31-Oct-2020
• ICS: 83.040.20 - Rubber compounding ingredients
• Technical Committee: D24 - Carbon Black
• Drafting Committee: D24.61 - Carbon Black Sampling and Statistical Analysis

Standards Content (Sample)

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.
Designation: D4821 − 20
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. Scope D1513 Test Method for Carbon Black, Pelleted—Pour Den-
sity
1.1 This guide covers procedures for using the ASTM
2 D1765 Classification System for Carbon Blacks Used in
Standard Reference Blacks (SRBs) and the HT and INR
Rubber Products
Iodine Number Standards to continuously monitor the preci-
D2414 Test Method for Carbon Black—Oil Absorption
sion of those carbon black test methods for which reference
Number (OAN)
values have been established. It also offers guidelines for
D3265 Test Method for Carbon Black—Tint Strength
troubleshooting various test methods.
D3324 Practice for Carbon Black—Improving Test Repro-
1.2 This guide defines the environmental conditions that are
ducibilityUsingASTMStandardReferenceBlacks(With-
4
required for laboratories that perform carbon black testing
drawn 2002)
activities for those test methods under D24’s jurisdiction.
D3493 Test Method for Carbon Black—Oil Absorption
Number of Compressed Sample (COAN)
1.3 This guide establishes procedures for the use of x-charts
to continuously monitor those tests listed in Section 2 for D6556 Test Method for Carbon Black—Total and External
Surface Area by Nitrogen Adsorption
within-lab precision (repeatability) and between-lab accuracy
(reproducibility). D7854 Test Method for Carbon Black-VoidVolume at Mean
Pressure
1.4 This guide provides a statistical procedure for improv-
E177 Practice for Use of the Terms Precision and Bias in
ing test reproducibility when a laboratory cannot physically
ASTM Test Methods
calibrate its apparatus to obtain the reference values of the
E2282 Guide for Defining the Test Result of a Test Method
ASTM reference blacks, within the ranges given in this guide.
E2586 Practice for Calculating and Using Basic Statistics
1.5 This international standard was developed in accor-
dance with internationally recognized principles on standard-
3. Terminology
ization established in the Decision on Principles for the
3.1 Definitions:
Development of International Standards, Guides and Recom-
3.1.1 accepted reference value, n—a value that serves as an
mendations issued by the World Trade Organization Technical
agreed-upon reference for comparison, and which is derived
Barriers to Trade (TBT) Committee.
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.
3.1.1.1 Discussion—A national or international
organization, referred to in (2), generally maintains measure-
1
ment standards to which the reference values obtained are
This guide is under the jurisdiction ofASTM Committee D24 on Carbon Black
and is the direct responsibility of Subcommittee D24.61 on Carbon Black Sampling
traceable. E177
and Statistical Analysis.
3.1.2 accuracy, n—the closeness of agreement between a
Current edition approved Nov. 1, 2020. Published November 2020. Originally
approved in 1988. Last previous edition approved in 2019 as D4821 – 19. DOI: test result and an accepted reference value.
10.1520/D4821-20.
3.1.2.1 Discussion—The term accuracy, when applied to a
2
Standard Reference Blacks are available from Laboratory Standards &
set of test results, involves a combination of a random
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 [e-mail]. 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 − 20
component and of a common systematic error or bias 3.1.12 observed value, n—the value obtained by making an
component. E177 observation. E2282
3.1.3 ASTM reference blac
...

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.
Designation: D4821 − 19 D4821 − 20
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. Scope
2
1.1 This guide covers 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 reference values have been
established. It also offers guidelines for troubleshooting various test methods.
1.2 This guide defines the environmental conditions that are required for laboratories that perform carbon black testing activities
for those test methods under D24’s jurisdiction.
1.3 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).
1.4 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.
1.5 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.
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)
D3265 Test Method for Carbon Black—Tint Strength
D3324 Practice for Carbon Black—Improving Test Reproducibility Using ASTM Standard Reference Blacks (Withdrawn
4
2002)
D3493 Test Method for Carbon Black—Oil Absorption Number of Compressed Sample (COAN)
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 Aug. 1, 2019Nov. 1, 2020. Published August 2019November 2020. Originally approved in 1988. Last previous edition approved in 20162019
as D4821 – 16.D4821 – 19. DOI: 10.1520/D4821-19.10.1520/D4821-20.
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 [e-mail]. 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 − 20
D6556 Test Method for Carbon Black—Total and External Surface Area by Nitrogen Adsorption
D7854 Test Method for Carbon Black-Void Volume at Mean Pressure
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E2282 Guide for Defining the Test Result of a Test Method
E2586 Practice for Calculating and Using Basic Statistics
3. Terminology
3.1 Definitions:
3.1.1 accepted reference value, n—a value that serves as an agreed-upon reference for comparison, and which is derived as: (1)
a theoretical or established value, based on scientific principles, (2) an assigned or certified value, based on experimental work of
some national or international organization, or (3) a consensus or certified value, based on collaborative experimental work under
the auspices of a scientific or engineering group.
3.1.1.1 Discussion—
A national or international organization, referred to in (2), generally maintains measurement standards to which the reference
values obtained are traceable. E177
3.1.2 accuracy, n—the closeness of agreement between a test result and an accepted reference value.
3.1.2.1 Discussion—
The term accuracy, when applied to a set of test results, involves a combination of
...