This part of International Standard IEC 61331 applies to materials in sheet form used for the manufacturing of protective devices against X-radiation of radiation qualities generated with X-ray tube voltages up to 400 kV and a total filtration of up to 3,5 mm Cu.

This part 1 is not intended to be applied to protective devices when these are to be checked for the presence of their attenuation properties before and after periods of use.