Through an X-ray test to EN 1435 or ASME Section V, Article 2, Edition 2010, for example, full penetration welds on thermowells can be investigated with respect to irregularities (cracks, voids, insufficient bonding).
Here, depending on the dimensions of the thermowell, up to five X-ray images may be necessary to determine irregularities with sizes < 0.5 mm in the full-penetration weld.
An X-ray examination can also be used to record the bore centrality in solid body material thermowells.
For this purpose, two images of the thermowell tip at 90° to each other are required.
credits: carl