Feed-through coil arrangement for use in a test apparatus for testing long products in a feed-through method by means of eddy current, comprising: an exciter coil arrangement with an exciter coil which surrounds a passage opening for feeding-through a long product along a feed-through direction, wherein the exciter coil arrangement comprises a connection device for connecting the exciter coil to an alternating current source; and a receiver coil arrangement arranged around the passage opening, which comprises a connection device for connecting the receiver coil arrangement to an evaluation device of the test apparatus, wherein the receiver coil arrangement comprises two or more segment coil arrangements (142-1 to 142-8, 742-1 to 742-8) distributed over the circumference of the passage opening, wherein each segment coil arrangement has a detection range that only covers a circumferential section of the circumference of the surface of the long product, characterized in that the segment coil arrangements (142-1 to 142-8, 742-1 to 742-8) are distributed over at least two shells (S1, S2) surrounding the passage opening at different distances (A1, A2) to a reference axis of the feed-through coil arrangement, wherein first segment coil arrangements (142-1 to 142-4, 742-1 to 742-4) are arranged on a first shell without reciprocal overlapping, second segment coil arrangements (142-5 to 142-8, 742-5 to 742-8) are arranged on a second shell without reciprocal overlapping, and first and second segment coil arrangements are arranged circumferentially offset to one another in circumferential direction such that the second segment coil arrangements detect circumferential sections that are not covered by the first segment coil arrangements. an exciter coil arrangement with an exciter coil which surrounds a passage opening for feeding-through a long product along a feed-through direction, wherein the exciter coil arrangement comprises a connection device for connecting the exciter coil to an alternating current source; and a receiver coil arrangement arranged around the passage opening, which comprises a connection device for connecting the receiver coil arrangement to an evaluation device of the test apparatus, wherein the receiver coil arrangement comprises two or more segment coil arrangements (142-1 to 142-8, 742-1 to 742-8) distributed over the circumference of the passage opening, wherein each segment coil arrangement has a detection range that only covers a circumferential section of the circumference of the surface of the long product, characterized in that the segment coil arrangements (142-1 to 142-8, 742-1 to 742-8) are distributed over at least two shells (S1, S2) surrounding the passage opening at different distances (A1, A2) to a reference axis of the feed-through coil arrangement, wherein first segment coil arrangements (142-1 to 142-4, 742-1 to 742-4) are arranged on a first shell without reciprocal overlapping, second segment coil arrangements (142-5 to 142-8, 742-5 to 742-8) are arranged on a second shell without reciprocal overlapping, and first and second segment coil arrangements are arranged circumferentially offset to one another in circumferential direction such that the second segment coil arrangements detect circumferential sections that are not covered by the first segment coil arrangements.