| 摘要 |
PURPOSE:To achieve a stable measurement of temperature for a long time, by inserting a thermocouple into a protective tube having ceramic tubes mounted doubly therein to protect the thermocouple positively from a CO gas generated at the protective tube and the like. CONSTITUTION:A first ceramic tube 12 is mounted integrally inside a protective tube 11, a second ceramic tube 13 arranged in the ceramic tube 12 and then, a thermocouple 19 inserted into the protective tube. Here, it is desired to feed gas such as air, nitrogen and argon intermittently and continuously into the second ceramic tube 13. With such an arrangement, the thermocouple 19 can be protected positively from a high-temperature CO gas that would be generated from the protective tube 11, mortar provided between the protective tube 11 and the first ceramic tube 12 and the like thereby preventing deterioration in the thermocouple 19 for a long time. |
