2. The contribution of different analysis techniques to expert appraisals

2.1 In situ analysis

It is not always possible to take the samples that will then be subjected to the analyses specified in the survey protocol, and it may also be useful to select the relevant area on site to sample for subsequent investigations.

Non-destructive testing techniques are mainly used, in the field of expert assessment, to characterize defects and identify the damaged area, e.g. an area with cracks. The table 2 provides an overview. COFREND (Confédération française pour les essais non destructifs) is the organization responsible for managing the national certification system for operators carrying out these tests.