| 摘要 |
PURPOSE:To accurately detect the temperature of a pipe by a method wherein a detection conductor is wound on the pipe and the conductor is covered with a thermosensitive control layer, whereas another detection conductor is wound on the layer, which is then covered with heat insulating material and the like. CONSTITUTION:A detection conductor 2 composed of nickel wires and so on is wound on a pipe 1 made of heat-resistant electric insulating material and the conductor is covered with a thermosensitive control layer 3 having such characteristics that its impedance decreases instantly when the temperature rises and then a detection conductor 2' is wound on the layer 3. Before being covered with an external coating 5 made of a heat insulator, the conductor 2' is covered with a coating 4 made of nylon and the like used to prevent conductive plastics within the control layer 3 from dispersing. The impedance between the conductors 2 and 2' becomes almost linear within the temperature range of 30-120 deg.C, so that the temperature of the pipe can be detected accurately. |
