| 摘要 |
<p>A metal pipe (1) bent into a serpentine or spiral shape is used. It has a resistivity of between 50 and 120 microhm. cm. and specified length, wall thickness and clear cross-section of a given shape. It is mounted in an outer case (4) filled with electrically and thermally insulating material, so that the pipe is not in contact with the case (4). One end of the pipe is connected to the water mains and the other to hot water tap. An electric power source giving low voltage and high current, is connected to the two ends of the pipe.</p> |
