“C” Evaluation—Differences Between “Mathematical” and “Physical” Possibilities

Abstract

A review of the pertaining ASME literature shows that so far all ASME efforts to assign “uncalibrated” tolerances to ASME devices (orifice plates, ASME nozzles, PTC-6 throat tap nozzles) failed when tested against a newer set of calibration data. The paper shows that the cause of failure may have been the use of statistical methods and/or mathematical generalizations without physical scrutinization of the calibration data and the device under investigation. The purpose of the paper, therefore, is to help to map out the “physical road” to reliable “C” evaluation work. Another purpose of the paper is to uncover some hidden obstacles that have retarded progress in this area and would assure failure for future investigators, unless recognized and handled properly.