Establishing Metrological Traceability Using Certified Reference Materials (CRMs): The Role Of The NBL Program Office As A CRM Producer

A critical step to ensure that the results of measurements are defensible in an accreditation environment or in response to regulatory requirements is to tie them to the international system of measurements (the SI). Establishing a traceability chain to the SI necessarily involves using physical metrology standards such as traceable mass and volume standards and chemical metrology standards commonly referred to as Certified Reference Materials (CRMs). In the chemical measurement process, both the instrument calibration step and the validation of measurement results employ different types of CRMs designed ensure the best possible link (lowest bias and overall uncertainty) to the SI. This presentation provides details on the characteristics and uses of different types of CRMs in isotope and assay measurement schemes. The NBL PO is authorized to prepare and distribute traceable CRMs to the U.S. nuclear complex and to appropriate international organizations. Specific examples of these CRMs, how they fit into the described type taxonomy, and how they are to be used are described.