Calibration Interval Adjustment Methods
Calibration Interval Adjustment Methods
Mark Kuster,
Pantex Metrology
NCSLI Recommended Practice RP-1, “Establishment and Adjustment of Calibration Intervals,”
provides decision trees for selecting a calibration interval adjustment method based
on inventory size, available data, quality emphasis, and budgeting priorities. RP-1 also describes
each method’s pros and cons and offers qualitative recommendations based on expert
knowledge and experience. Since releasing the current RP edition, the NCSLI 173.1 Calibration
Intervals Working Group has sought to develop quantitative performance data on
interval adjustment methods to further substantiate or tune the existing recommendations.
Ultimately, the research will identify and map the optimal interval adjustment method into
each region of the operational space determined by equipment inventory size, reliability target,
and other parameters, enabling the future RP-1 reader to confidently select the most
appropriate method for the situation at hand. This paper reports the latest progress toward
that goal, including framework improvements such as AOPR and instrument lifetime simulation,
adjustment method parameter optimizations, and simulation results to date. We
compare results based on an excess relative cost metric, which estimates the cost premium an
interval adjustment method, or lack thereof, incurs in a measurement and testing program.