ASTM C 670a:2024

1.1 The Form and Style for ASTM Standards requires that all test methods contain statements on precision and bias. Further, the precision statement is required to contain a statement on single-operator precision (repeatability) and a statement on multilaboratory precision (reproducibility). This practice provides guidance for preparing precision and bias statements that comply with these requirements. Discussion of the purpose and significance of precision and bias statements for users of test methods is also provided. Examples of precision statements that conform to this practice are included in Appendix X1 . This practice supplements Practice E177 and has been developed to meet the needs of ASTM Committees dealing with construction materials. Note 1: Although this practice is under the jurisdiction of Committee C09, the current version was developed jointly by Committees C01 and C09 and has subsequently been adopted for use by other committees dealing with construction materials. 1.2 This practice assumes that an interlaboratory study (ILS) has been completed in accordance with Practice C802 or Practice E691 . The interlaboratory study provides the necessary statistical values to write the precision and bias statements. 1.3 The system of units for this practice is not specified. Dimensional quantities in the practice are presented only in examples of precision and bias statements. 1.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 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.

91.100.01