This document specifies an infrared absorption method after combustion in an induction furnace for the determination of non-combined carbon content in cast irons. The method is applicable to non-combined carbon contents between 1,0 % (mass fraction) and 3,0 % (mass fraction). Elements ordinarily present do not interfere. However, some alloyed cast irons, when extensively heat treated, contain carbides that are not soluble when using this method and may give high values for non combined carbon.