ASTM D 4821 : 1999

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.