INSPECTION METHOD FOR TUBE OR TUBE CABLE

摘要

PROBLEM TO BE SOLVED: To inspect the inside diameter of a plastic tube or tube cable for passing an optical fiber communication wire. SOLUTION: A tube 1 for passing a communication wire is previously inserted with a metal ball 2 having diameter smaller than the inside diameter of tube 1 and then the tube 1 is moved upward. If a part having inside diameter shorter than the diameter of metal ball 2 is present, the metal ball 2 is also moved upward and detected by means of a metal sensor 3 disposed on the outside of tube 1 thus inspecting the inside of tube continuously.