ASTM E3330-22

SIGNIFICANCE AND USE 5.1 This guide is intended for use by developers of RMs and CRMs for the metals and mining industries. 5.2 The guidance is related to uniform procedures and requirements and is intended to prevent the proliferation of widely varying documentation practices, definitions, and terminology. Where the statements in this guide are made as imperatives, it is because the stated practices are fundamental to chemical metrology, not to CRM/RM development. 5.3 The material in this guide is intended to supplement and to clarify the contents of ISO Guide 31 and to provide guidance specific to the needs of the metals and mining industries. 5.4 The documents described in this guide are intended to contain the minimum amount of information required for a user to understand the material, to help a user judge the quality of the product, and to help a user employ it in appropriate ways. Neither this guide nor resultant documents are meant to be encyclopedic. 5.5 Because this document is a standard guide, it is intended to educate those who are involved in laboratory operation, quality system development and maintenance, reference material development, and accreditation of laboratory operations within the scope of a quality system. It must be understood by all parties that the elements of this guide discuss optional practices having numerous choices for accomplishment and documentation. However, this guide does not constitute requirements for assessment and accreditation. An obvious example is statistical evaluation for consensus value and uncertainty calculations, which can take many forms with no single, correct choice for any given case. 5.6 When using this guide, CRM developers will set goals for the material under development, such as target uncertainties for homogeneity and for overall coverage intervals for assigned values. These choices are based on the intended uses of a CRM. The material, property values, and their uncertainties may or may not meet the set goals... SCOPE 1.1 This guide is designed to explain and to clarify documentation that accompanies an RM or a certified reference material (CRM). It explains the contents of certificates of analysis for CRMs and product information documents for RMs, based on existing international standards and guides. It briefly touches on the minimum requirements for a label attached to the CRM/RM unit or unit container and to the package containing the unit or unit container. 1.2 This guide provides some basic guidance on calculation of consensus values and uncertainty estimates for CRMs and RMs with examples of approaches commonly used by national metrology institutes and suggestions for sources of information. 1.3 Units—The values stated in SI units are to be regarded as the standard, whenever applicable. Values can be traceable to other higher-order reference systems, including Rockwell Hardness, pH, and other systems defined by an international standard or peer-reviewed publication. 1.4 Contents—Sections and topics within this guide are enumerated below: Section Title 1 Scope 2 Referenced Documents 3 Terminology 4 Summary of Guide 5 Significance and Use 6 Contents of a Certificate of Analysis or Reference Material Documentation 7 Labels 8 Technical and Statistical Evaluations 9 Procedures for Consensus Value Calculations 10 Estimation of Uncertainty 11 Reporting Values and Uncertainty Estimates 12 International System of Units 13 Keywords Appendix X1 Working Near Zero Appendix X2 Working Near 100 % Appendix X3 Censored Values Appendix X4 Examples of Language for Sections of a Certificate of Analysis 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, health, and enviro...