Читать книгу Paint Analysis - Roger Dietrich - Страница 38

What is the main task after a failure occurs, it has been decided to investigate the root cause and the design of experiment is fixed? You would want to have reliable samples in the first place. Reliable samples are those that ideally represent the issue most comprehensively. A sampling error is the deviation of a parameter of the sample versus the whole population. That means, the essential prerequisite is that the samples suffer a minimum of “bad influence” from the beginning of the sampling to the preparation for analysis, which alter the status of the moment when the failure happened. The sample area to be analysed must be saved. So as simple as it is, the selection of “right” samples is a challenge.