A typical lot of NIST SRMs has 300 units, with 5 specimens in each unit. These SRMs are tested by customers and the customer verification data is returned to NIST for evaluation according to the requirements of ASTM E23. Once a minimum of 50 verification results are returned to NIST for a particular lot, we generate a file for download on this website. (The files are updated periodically.)
A NIST PT report compares the performance of a particular customer machine to a minimum of 50 other customers that tested the same lot of verification specimens. The comparison uses general statistics to provide information on the performance of the machine being evaluated, and indicates when performance is outside of expected bounds.
A PT report can be produced by following the directions for each of the steps listed below:
(1) Download the R- Software (open source).
(2) Download the NIST PT analysis program.
(3) Download the Data Files for SRM lot tested.
(4) Instructions on Running the program.