A method for measuring the centricity of a conductor in an insulation sleeve, in which the string formed by the conductor with its insulation sleeve is moved along a conveying direction, comprising the following steps: - in an inductive measuring plane, the position of the conductor is determined by means of an inductive measuring apparatus, - in a first optical measuring plane, which lies in the conveying direction of the string in front of the inductive measuring plane, the position of the string is determined by means of at least one first optical measuring apparatus, - in a second optical measuring plane, which lies in the conveying direction of the string behind the inductive measuring plane, the position of the string is determined by means of at least one second optical measuring apparatus, - the positions of the string determined in the first and second optical measuring plane are correlated such that a position of the string in the inductive measuring plane results, and - from this resulting position of the string in the inductive measuring plane and from the position of the conductor determined in the inductive measuring plane, the centricity of the conductor in the insulation sleeve is determined, - wherein, in the first optical measuring plane and/or in the second optical measuring plane, a spatially resolved optical measurement takes place on the one hand perpendicular to the conveying direction and on the other hand in the conveying direction, such that a sloping position and/or a curvature of the string with respect to the conveying direction is identified in the first optical measuring plane and/or in the second optical measuring plane, wherein such a sloping position and/or curvature is taken into account during the determination of the centricity of the conductor in the insulation sleeve. - in an inductive measuring plane, the position of the conductor is determined by means of an inductive measuring apparatus, - in a first optical measuring plane, which lies in the conveying direction of the string in front of the inductive measuring plane, the position of the string is determined by means of at least one first optical measuring apparatus, - in a second optical measuring plane, which lies in the conveying direction of the string behind the inductive measuring plane, the position of the string is determined by means of at least one second optical measuring apparatus, - the positions of the string determined in the first and second optical measuring plane are correlated such that a position of the string in the inductive measuring plane results, and - from this resulting position of the string in the inductive measuring plane and from the position of the conductor determined in the inductive measuring plane, the centricity of the conductor in the insulation sleeve is determined, - wherein, in the first optical measuring plane and/or in the second optical measuring plane, a spatially resolved optical measurement takes place on the one hand perpendicular to the conveying direction and on the other hand in the conveying direction, such that a sloping position and/or a curvature of the string with respect to the conveying direction is identified in the first optical measuring plane and/or in the second optical measuring plane, wherein such a sloping position and/or curvature is taken into account during the determination of the centricity of the conductor in the insulation sleeve.