WG 7 - TC 112/WG 7

IEC TR 60493-3:2017(E) clarifies how a statistical analysis can be done with a small number of samples.
This document will be useful when the accelerated test method is difficult to carry out, for example in cases where the dimensions of test specimens (including test devices) are very large in scale or the cost of test specimens is high. Testing is facilitated by enabling users to reduce the number of test specimens.

IEC 60493-1:2011 gives statistical methods which may be applied to the analysis and evaluation of the results of ageing tests. It covers numerical methods based on mean values of normally distributed test results. These methods are only valid under specific assumptions regarding the mathematical and physical laws obeyed by the test data. Statistical tests for the validity of some of these assumptions are also given. This standard deals with data from both complete test sets and censored test sets. This standard provides data treatment based on the concept of "data sub-group" as defined in Clause 3. The validity of the coefficients used in the calculation processes to derive statistical parameters of the data groups are described in IEC 60216-1. This second edition cancels and replaces the first edition, published in 1974, and constitutes a technical revision. The main changes with respect to the first edition are that, besides a complete editorial revision, censored data sub-group are considered.

Describes, with examples, statistical methods to analyze times to break down and breakdown voltage data obtained from electrical testing of solid insulating materials, for purposes including characterization of the system, comparison with another insulator system, and prediction of the probability of breakdown at given times or voltages.