Abstract: A method and an apparatus for measuring an electric insulated conductor, in particular a medium-voltage and/or high-voltage insulated conductor, are proposed. Seen in profile cross-section, the insulated conductor (50) comprises a copper conductor, an inner semiconductor, an insulation and an outer semiconductor and is produced in an extrusion device (90) having an appropriately assigned crosslinking section (40). To achieve an even distribution of the two semiconductor layers and of the insulation layer, the insulated conductor (50) is radiated through immediately at the outlet from the crosslinking section (40) and a correction of the die setting in the extrusion device is carried out using the values thus determined.