Apparatus for measuring the content of hydrogen dissolved in molten metal, comprises an immersion head 2 immersed within a batch 4 of the molten metal to bring circulated inert gas into contact with the molten metal. A hydrogen gas content measuring device 24 connected to the gas passage 10 from the head 2 measures the hydrogen- content of the inert gas flowing through the gas passage, the measuring device comprising a first measuring cell 27 connected to the gas passage 10 and having therein an electric resistance wire exposed to the circulated inert gas containing the hydrogen picked up from the molten metal, and further comprising a second measuring cell 27 filled with atmosphere whose thermal conductivity is substantially equal to that of the inert gas. The measuring device 24 includes a housing block which has portions to define a vacuum chamber surrounding the measuring cells 27 in order to thermally separate the cells from the atmosphere surrounding the measuring device. IMAGE
展开▼
