ISO 16823:2012 specifies the principles of transmis­sion techniques.
Transmission techniques can be used for: a) detection of imperfections; b) determination of attenuation.
The general principles required for the use of ultrasonic examina­tion of in­dustrial products are described in ISO 16810.
The transmission technique is used for examination of flat pro­ducts, e.g. plates and sheets.
Further, it is used for examinations e.g.: 1) where the shape, dimensions or orientation of possible imperfections are unfavourable for direct reflection; 2) in materials with high attenuation; 3) in thin products.