NIST Standards for Microanalysis and the Certification Process

The National Institute of Standards and Technology (NIST) has been involved in the development of standards for microanalysis since the middle of the 1960s. Certification of "traceable" standards that can be sold to other laboratories is time-consuming and costly, especially when the extent of microheterogeneity within each specimen becomes part of the uncertainty assigned to the certified values. The process of certification of microanalysis standards and the improvements that have facilitated the process with the development of automation and computerization are reviewed.