摘要 |
PURPOSE:To achieve a higher detection sensitivity, by removing a gold clad on a hot wire by evaporation after mounted while material of the hot wire is thermally treated at a temperature of recrystallization thereof. CONSTITUTION:After being formed and machined, a detection element 1 is connected to a control power source 3 through a power source wire 2 in such a manner as to be allowed to energize hot wires 14 and mounted in a chamber 4 to be sealed up. An exhauster 5 such as vacuum pump is connected to the chamber 4 and, after the sealing of the detection element 11, the chamber 4 is exhausted to vacuum below 1.5Pa. Then, the power source 3 is actuated to energize the hot wires 14 at a temperature and a time length enough to remove a gold clad on the hot wires 14 by evaporation and a heat treatment is performed. Here, the wires 14 are adjusted to the temperature above 1,500 deg.C if made of tungsten to accomplish a secondary crystallization of the tungsten material. |