ASTM D4821-99

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

SCOPE
1.1 This guide covers a procedure for using ASTM Standard Reference Blacks (SRBs) to continuously monitor the precision of those carbon black test methods for which standard values have been established. It also offers guidelines for trouble-shooting various test methods.
1.2 This guide establishes the limits within which the statistical calibration procedure of Practice D3324 shall be applied and establishes the limits for an out-of-calibration condition beyond which the statistical calibration procedure of Practice D3324 shall not be applied.
1.3 This guide uses statistical control chart methodology as discussed in STP-15-D to determine if a laboratory's test results differ significantly from the accepted values of the SRBs and provides a format for reporting test data for specified tests on the SRB blacks.
1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.5 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: 09-Dec-2001
• ICS: 83.040.20 - Rubber compounding ingredients
• Technical Committee: D24 - Carbon Black
• Drafting Committee: D24.61 - Carbon Black Sampling and Statistical Analysis

Relations

• Replaced By: ASTM D4821-01 - Standard Guide for Carbon Black—Validation of Test Method Precision and Bias
• Effective Date: 10-Dec-2001
• Referred By: ASTM D3493-21 - Standard Test Method for Carbon Black—Oil Absorption Number of Compressed Sample (COAN)
• Effective Date: 10-Dec-2001
• Referred By: ASTM D8466-22 - Standard Guide for Recovered Carbon Black—Carbon Black Test Methods for Testing rCB
• Effective Date: 10-Dec-2001
• Referred By: ASTM D1510-23 - Standard Test Method for Carbon Black—Iodine Adsorption Number
• Effective Date: 10-Dec-2001
• Referred By: ASTM D8043-20 - Standard Guide for Carbon Black—Shelf Life
• Effective Date: 10-Dec-2001
• Referred By: ASTM D3265-23 - Standard Test Method for Carbon Black—Tint Strength
• Effective Date: 10-Dec-2001
• Referred By: ASTM D2414-23 - Standard Test Method for Carbon Black—Oil Absorption Number (OAN)
• Effective Date: 10-Dec-2001
• Referred By: ASTM D6915-23 - Standard Practice for Carbon Black—Evaluation of Standard Reference Blacks
• Effective Date: 10-Dec-2001

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 4821 – 99
Standard Guide for
Carbon Black—Validation of Test Method Precision and
Bias
This standard is issued under the fixed designation D 4821; 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 D 3493 Test Method for Carbon Black—n-Dibutyl Phtha-
late Absorption Number of Compressed Sample
1.1 This guide covers a procedure for using ASTM Standard
D 3765 Test Method for Carbon Black—CTAB (Cetyltrim-
Reference Blacks (SRBs) to continuously monitor the preci-
ethylammonium Bromide) Surface Area
sion of those carbon black test methods for which standard
D 4820 Test Methods for Carbon Black—Surface Area by
values have been established. It also offers guidelines for
Multipoint B. E. T. Nitrogen Adsorption
trouble-shooting various test methods.
1.2 This guide establishes the limits within which the
3. Significance and Use
statistical calibration procedure of Practice D 3324 shall be
3.1 One of the major causes of poor test precision is the lack
applied and establishes the limits for an out-of-calibration
of calibration or standardization of instruments, apparatus,
condition beyond which the statistical calibration procedure of
reagents, and technique among laboratories.
Practice D 3324 shall not be applied.
3.2 In addition to the calibration of a test method by
1.3 This guide uses statistical control chart methodology as
2 physicochemical means, Practice D 3324 describes a statistical
discussed in STP-15-D to determine if a laboratory’s test
method for achieving calibration of a test method.
results differ significantly from the accepted values of the
3.3 This guide outlines the use of control charts to graphi-
SRBs and provides a format for reporting test data for specified
cally present calibration test data determined for the ASTM
tests on the SRB blacks.
SRBs for those test methods given in Section 2. These control
1.4 The values stated in SI units are to be regarded as the
charts shall be used to validate the testing precision and bias of
standard. The values given in parentheses are for information
an individual laboratory.
only.
1.5 This standard does not purport to address all of the
4. Procedure
safety concerns, if any, associated with its use. It is the
4.1 Select six SRBs from the SRB 4 and SRB 5 series to
responsibility of the user of this standard to establish appro-
cover the range of interest, being sure to include one each of
priate safety and health practices and determine the applica-
the A, B, C, D, E, and F (see Note 1) SRBs.
bility of regulatory limitations prior to use.
NOTE 1—F-5 will not be available for purchase until F-4 is depleted.
2. Referenced Documents
4.2 Prepare a control chart for each of the selected SRBs for
2.1 ASTM Standards:
each test method as presented by Part 3 of ASTM STP 15D.
D 1510 Test Method for Carbon Black—Iodine Adsorption
4.3 The target values given in Table 1 and Table 2 are the
Number
nominal SRB values reported in Practice D 3324. Values are
D 2414 Test Method for Carbon Black—n-Dibutyl Phtha-
used as control chart limits plus or minus three single test
late Absorption Number
repeatability standard deviations as given in the precision
D 3037 Test Methods for Carbon Black—Surface Area by
section of each applicable test method for the SRB 4s or as
Nitrogen Adsorption
determined during the validation of the SRB 5s.
D 3265 Test Method for Carbon Black—Tint Strength
4.4 Plot the uncorrected values for the selected six SRBs
D 3324 Practice for Carbon Black—Improving Test Repro-
until a repeatability control limit is exceeded (see Note 2).
ducibility Using ASTM Reference Blacks
Perform a retest immediately. If the retest falls outside the
repeatability control limits, then begin a search for an assign-
This guide is under the jurisdiction of ASTM Committee D-24 on Carbon Black able cause. (See Section 5 for a list of assignable causes.) If the
and is the direct responsibility of Subcommittee D24.61 on Carbon Black Sampling
search for an assignable cause and the subsequent action taken
and Statistical Analysis.
still do not produce results within the control limits, then a
Current edition approved Dec. 10, 1999. Published January 2000. Originally
statistical regression or correction equation shall be calculated
published as D4821 – 88. Last previous edition D4821 – 98.
Symposium on Manual on Presentation of Data and Control Chart Analysis,
as described in Practice D 3324.
ASTM STP 15D, ASTM, 1976.
Annual Book of ASTM Standards, Vol 09.01. NOTE 2—Selected SRBs from SRB 4 and SRB 5 may be plotted on
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
D 4821
A
TABLE 1 Control Chart Limits
4.9 This procedure prescribes only the minimum action
Control Chart needed to continuously monitor test precision. Additional SRB
Test ASTM Target
SRB Repeatability
testing may be done and correction equations regularly recal-
Property Standards Value
3s Limits
culated at individual discretion.
Iodine D 1510 A-4 82.7 60.86
4.10 An example of determining a correction equation for
Adsorption B-4 79.3 60.97
SRBs A-4, B-4, C-4, D-4, E-4, and F-4 for DBP Absorption
Number, C-4 121.3 61.51
g/kg D-4 26.5 61.56
Number is as follows:
E-4 36.0 60.57
The correction equation is: Y 5 Ax 1 B or
F-4 37.7 61.06
Corrected Value ~CV!
DBP D 2414 A-4 70.8 60.95
5 A actual value! 1 B (1)
~
Absorption B-4 100.0 61.37
Number, C-4 131.0 61.45
where:
−5 3 3
10 m /kg (cm /100 g) D-4 64.8 61.31
B 5 Y intercept, and
E-4 90.4 62.24
F-4 130.6 61.91
A 5 slope.
4.11 Examples of control charts for the six SRBs are shown
DBP Number D 3493 A-4 68.3 61.94
in Fig. 1 and Fig. 2.
Compressed B-4 86.6 62.03
Sample, C-4 108.9 61.64
−5 3 3
10 m /kg (cm /100 g) D-4 58.9 61.67
5. Assignable Causes
E-4 75.7 61.79
F-4 88.0 62.00
5.1 The following lists suggest several assignable causes as
possible reasons for a test to be out of statistical control.
CTAB D 3765 A-4 82.5 63.47
5.1.1 Test Method D 1510 Iodine Adsorption Number:
Surface B-4 79.1 63.04
Area, C-4 120.5 64.07
5.1.1.1 Incorrect normality of iodine and sodium thiosulfate
3 2 2
10 m /kg (m /g) D-4 24.9 62.61
solutions,
E-4 36.6 61.70
5.1.1.2 Volumetric glassware not calibrated correctly,
F-4 40.5 61.52
5.1.1.3 Purity of water insufficient,
Nitrogen D 3037 A-4 77.3 60.79
5.1.1.4 Incorrect pipet size, and
Surface B-4 74.4 61.59
5.1.1.5 Incorrect cleaning and rinsing of glassware with
Area, C-4 124.2 61.64
3 2 2
10 m /kg (m /g) D-4 24.1 60.37
dirty water.
E-4 34.6 60.81
5.1.2 Test Method D 2414 DBP Absorption Number:
F-4 38.5 60.62
5.1.2.1 Incorrect cooling time between samples,
Tint Strength D 3265 A-4 110.8 61.76
5.1.2.2 Incorrect setting of torque spring and collar,
B-4 98.5 62.03
5.1.2.3 Incorrect setting of torque limit switch,
C-4 119.5 62.21
D-4 41.2 61.20 5.1.2.4 Excessive blade and bowl clearance,
E-4 55.2 61.03
5.1.2.5 Incorrect finish roughness,
F-4 55.8 61.44
5.1.2.6 Incorrect dashpot oil level,
A
Single point nitrogen surface area (D 3037) targets determined by multipoint
5.1.
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