Molten metal gas analysis

Apparatus for determining the concentration of a selected gas in molten metal of known temperature and composition, other than dissolved gases, comprising a tubular probe having an outer sheath impermeable to the metal constructed from a gas permeable refractory for immersion in the melt, gas conducting means for passing a known gas selected from the group consisting of hydrogen, carbon monoxide and nitrogen together with argon, within the probe so as to realise an equilibrium condition, via the sheath, with the gas dissolved in the melt and an analyser calibrated with said known gas for analysing the equilibrated gas collected from the probe whereby to determine the concentration of the selected gas in said melt.

A method for determining the concentration of a selected gas in molten metal of known temperature and composition, other than dissolved gases, comprising passing a gas of known composition through gas conducting means in a tubular probe having an outer sheath impermeable to the metal but permeable to said selected gas which is immersed in molten metal so as to realise an equilibrium condition via the outer sheath with the gas dissolved in the melt and the gas passing through the gas conducting the means and measuring the equilibrium concentration of said selected gas passed through the gas conducting means.