| 摘要 |
PURPOSE:To detect easily the external damage of a cable by arranging an airtight tube of which one end is closed in the cable along the longitudinal direction of the cable, and keeping the inner pressure of the airtight tube to a value different from atmospheric pressure, measuring the change of pressure difference between the inner pressure of the airtight tube and the atmospheric pressure by a pressure meter. CONSTITUTION:The cable is obtained by twisting plural cable cores 1 and storing these cable cores 1 in a cable sheath 3 together with the tube 2 enabled to resist neccessary inner pressure. Terminal parts 21 are connected to both ends of the cable 22, and a pressure medium coupling pipe 23, a valve 25 and a pressure meter 24 are connected to the terminal parts 21. One end of the tube 2 is closed and air or the like is injected from the other end with the pressure more than atomospheric pressure, so that the pressure meter 24 can detect the generation of external damage on the cable immediately. |
