Estimation of ultrasonic beam parameters uncertainty from NDT immersion probes using Monte Carlo method

Abstract

This paper presents the calculation of ultrasonic beam parameters focal distance, focal length, and focal widths on X-axis and Y-axis for non-destructive testing probes. The measurement uncertainties were estimated using Monte Carlo Method, and compared to those obtained using Guide to the expression of uncertainty in measurement (GUM) approach. The results show that the mean values and the combined uncertainties are identical, but the probabilistically symmetric 95 % coverage intervals determined on the basis of the GUM uncertainty framework were more conservative than the ones achieved using Monte Carlo Method. Moreover, the calculation of the numerical tolerance between the coverage intervals obtained from Monte Carlo Method and GUM shows they are statistically different. Hence, a more conservative uncertainty approach will be achieved using GUM uncertainty framework.