IEC 62667:2017 applies to light ion beam ME equipment when used, for therapy purposes, in human medical practice.This document applies to light ion beam ME equipment which delivers light ion beams with an energy per nucleon in the range 10 MeV/n to 500 MeV/n.This document describes measurements and test procedures to be performed by the manufacturer of light ion beam ME equipment but does not specify acceptance tests.This document specifies test procedures for the determination and disclosure of performance characteristics, knowledge of which is necessary for proper selection, application, and use of light ion beam ME equipment and which are to be declared in the accompanying documentation together with the greatest deviation or variation to be expected under specific conditions in normal use. A format for presentation of performance values is given in Annex A.