OXYGEN PARTIAL PRESSURE DETECTOR OF HEATING CHAMBER

• Main Authors: TANAKA TATSUMI, OSHIRO RIKIYA, MIYAKOSHI NOBORU, HARAI SATORU, MACHI TETSUJI
• Format: Patent
• Language: English
• Published: 27.03.2008
• Subjects: CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION

PROBLEM TO BE SOLVED: To provide an oxygen partial pressure detector of a heating chamber capable of prolonging the lifetime of a zirconia type oxygen sensor for measuring the oxygen partial pressure in the heating chamber of a vacuum carburization furnace, and reducing the frequency for exchange. SOLUTION: A pipe 22 for detection is provided in a heating chamber 6 of a vacuum carburization furnace 1, a first on-off valve 20, a sensor fitting pipe 21, a second on-off valve 23, a pipe 36, and a third on-off valve 24 are successively connected to each other, and connected to a vacuum pump 10. A zirconia type oxygen sensor 30 is provided on a counter end 21b side of the sensor fitting pipe so that a detection unit 31 is located inside the sensor fitting pipe. During the vacuum carburization, the first on-off valve is closed, and any one or both of the second and third on-off valves are closed so that the zirconia type oxygen sensor is not subjected to the contact reaction with a hydrocarbon gas in the heating chamber. COPYRIGHT: (C)2008,JPO&INPIT