ASTM D4821-16

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.

General Information

• Status: Historical
• Publication Date: 30-Jun-2016
• 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)

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 − 16
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 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 defines the environmental conditions that are
ASTM Test Methods
required for laboratories that perform carbon black testing
E2282 Guide for Defining the Test Result of a Test Method
activities for those test methods under D24’s jurisdiction.
E2586 Practice for Calculating and Using Basic Statistics
1.3 This guide establishes procedures for the use of x-charts
3. Terminology
to continuously monitor those tests listed in Section 2 for
within-lab precision (repeatability) and between-lab accuracy
3.1 Definitions:
(reproducibility).
3.1.1 accepted reference value, n—a value that serves as an
agreed-upon reference for comparison, and which is derived
1.4 This guide provides a statistical procedure for improv-
as: (1) a theoretical or established value, based on scientific
ing test reproducibility when a laboratory cannot physically
principles, (2) an assigned or certified value, based on experi-
calibrate its apparatus to obtain the reference values of the
mental work of some national or international organization, or
ASTM reference blacks, within the ranges given in this guide.
(3) a consensus or certified value, based on collaborative
2. Referenced Documents
experimental work under the auspices of a scientific or
3
engineering group.
2.1 ASTM Standards:
3.1.1.1 Discussion—A national or international
D1510 Test Method for Carbon Black—Iodine Adsorption
organization, referred to in (2), generally maintains measure-
Number
ment standards to which the reference values obtained are
D1513 Test Method for Carbon Black, Pelleted—Pour Den-
traceable. E177
sity
D1765 Classification System for Carbon Blacks Used in 3.1.2 accuracy, n—the closeness of agreement between a
Rubber Products test result and an accepted reference value.
D2414 Test Method for Carbon Black—Oil Absorption 3.1.2.1 Discussion—The term accuracy, when applied to a
Number (OAN) set of test results, involves a combination of a random
D3265 Test Method for Carbon Black—Tint Strength component and of a common systematic error or bias
component. E177
3.1.3 ASTM reference blacks, n—a set of carbon blacks that
1
This guide is under the jurisdiction ofASTM Committee D24 on Carbon Black
span the useful range of the test method for which they are
and is the direct responsibility of Subcommittee D24.61 on Carbon Black Sampling
reference materials. D3324
and Statistical Analysis.
Current edition approved July 1, 2016. Published August 2016. Originally
3.1.4 bias, n—the difference between the expectation of the
approved in 1988. Last previous edition approved in 2015 as D4821 – 15. DOI:
test results and an accepted reference value.
10.1520/D4821-16.
2
Standard Reference Blacks are available from Laboratory Standards &
3.1.4.1 Discussion—Bias is the total systematic error as
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 − 16
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
...

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 − 15 D4821 − 16
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.
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)
D6556 Test Method for Carbon Black—Total and External Surface Area by Nitrogen Adsorption
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.
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 Jan. 1, 2015July 1, 2016. Published February 2015August 2016. Originally approved in 1988. Last previous edition approved in 20142015 as
D4821 – 14.D4821 – 15. DOI: 10.1520/D4821-15.10.1520/D4821-16.
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.
3.1.1.1 Discussion—
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D4821 − 16
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 a random component and of a common
systematic error or bias component. E177
3.1.3 ASTM reference blacks, n—a set of carbon blacks that span the useful range of the test method for which they are reference
materials. D3324
3.1.4 bias, n—the difference between the expectation of the test results and an accepted reference value.
3.1.4.1 Discussion—
Bias is the total systematic error as
...