Astm D 4821 – 03a pdf free download

Standard Guide for
Carbon Black—Validation of Test Method Precision and
Bias1

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 the 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

1.1 This guide covers a procedure for using ASTM Standard
Reference Blacks2 (SRBs) to continuously monitor the precision of those carbon black test methods for which standard
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 monitoring 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.

1.3 This guide uses statistical control chart methodology as
discussed in STP-15-D3 to determine if a laboratory’s test
results differ significantly from the accepted values of the
SRBs.

1.4 This guide provides a statistical procedure for improving test reproducibility when a laboratory cannot physically
calibrate its apparatus to obtain the standard values of the
ASTM SRBs, within the ranges given in the precision statement of the test method.

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.