GB1360962A - Apparatus for measuring in a continuous manner oxygen in a molten metal - Google Patents

Abstract

1360962 Electro-chemical analysis RST INTERNATIONAL METALS Ltd ME TALLURGIE HOBOKEN-OVERPELT and F D RICHARDSON 24 Jan 1973 [31 Jan 1972] 3615/73 Heading G1N A solid electrolyte dipper probe for measuring the oxygen content of a molten metal includes a solid electrolyte C mounted in a tube E which has a high resistance to mechanical stresses, thermal shocks and to chemical attack and which is extended at its lower end e.g. by about 1 to 5 cm. When the probe is dipped into a molten metal sample air is trapped in the tube E between levels X, Y and expands to blow away slag &c. which may be present on the metal surface and also conducts heat to the solid electrolyte tube, rod or plug C to pre-heat it. The liquid metal slowly rises to the level X as the air escapes either through the cement fastening the electrolyte C and refractory ring D to the tube E or through a hole provided in tube E at level X. In order to suppress stray e.m.f's which may be set up due to the refractory materials used for the cement and ring D a metal oxide such as nickel oxide may be incorporated in the cement in which the oxygen is held at a chemical potential approaching the chemical potential of the oxygen in the sample. The tube E may be steel, steel alloy, silica, alumina or silicon carbide.