Define Limitations of Radiography - Underwater Inspection of Bridge?
i. Radiography is a costly and time consuming method, which re- quires extensive safety measures to be adopted at site.
ii. Radiography may miss cracks, which are not parallel to the radiation beam or are in thick sections.
Computerised Tomography (CT), which is again based on radiography, is a recent and more advanced method. With this, voids can be located, steel locations can be pinpointed and sections can be indicated accurately.