Which of the following best describes the double wall exposure, single wall viewing technique for performing radiography?

The double wall exposure, single wall viewing technique for performing radiography is best described by the option stating that the radiation passes through two walls and only the film side wall is viewed for acceptance.

This technique is specifically designed to enhance the inspection process in situations where two walls of a pipe or vessel may need to be examined for internal defects. By allowing the radiation to penetrate both walls, the inspector can capture information about any defects that may be present in either wall. However, the key part of this technique is that the film, which records the radiographic images, is positioned to only capture the information from the wall adjacent to the film side. This focused viewing helps to streamline the inspection process and minimizes the potential for complicating the interpretation of the radiographic film, as only the relevant wall's image is presented for analysis.

This method is advantageous because it simplifies the analysis—inspectors can assess the suitability or quality of the weld or metal structure without being distracted by images from both walls simultaneously, which may introduce confusion or misinterpretation of the results.