Typical scenarios within this site’s subject: questions to ask, materials to prepare and points that can be examined.
Typical scenarios
If a metal part has high surface hardness, that reading may be reported as a property of the whole item. Surface hardening can leave the core and outer layer different. The review requires an oriented specimen and a depth profile rather than further measurements confined to the exterior.
Typical scenarios
If tensile strength uses the area after fracture, it may not match the specified engineering quantity even when maximum force was measured correctly. Separate original area, final area and stress definitions.
Typical scenarios
Smooth and rough fracture regions may be labelled fatigue and final overload. Dismantling or cleaning may also damage surfaces. Preserve both halves, their orientation and post-discovery handling history.
Typical scenarios
If transparent fragments in a jacket pocket are compared with a broken display window, appearance is insufficient. Several panes may be involved and pocket particles may have different origins. Separate them and obtain representative samples from each relevant pane.
Typical scenarios
Suppose apparently similar fibres are found on two objects that shared packaging before examination. Direct contact is suggested, but potential transfer during storage must also be considered.
Typical scenarios
If recovered coating fragments are to be compared with a car after a damaged panel was repainted, its new condition cannot be treated as an unchanged sample of the earlier coating. Analysis would need to establish which areas were repaired, what original coating remains and where each comparison material came from.
