The invention relates to a measuring head (1) which is used in measuring an assembly part, more particularly a fuel rod (54) of a fuel element box and/or a spacer of a nuclear facility. The invention aims at providing a measuring head that makes it possible to augment a comparatively large data base representing the overall aging state of the fuel elements in a simple manner and within a short measuring time. To this end, the measuring head (1) has a probe tip (4) arranged in the probe housing (2), wherein a thickness layer measuring probe (30) is integrated into said probe housing (2), said measuring probe working according to the eddy current principle. The contour or the diameter of the fuel rod can be determined by the measured deflection of the probe.
