Method for measuring temperature of molten metal received in vessel

Claim 1

In a method for measuring the temperature of a molten metal received in a casting vessel, the molten metal received in said casting vessel having molten slag floating on the upper surface thereof, which comprises: covering at least the tip portion of a probe comprising a thermocouple housed in an alumina protecting tube, from inside to outside, with a ceramic fiber and a quartz glass layer over said ceramic fiber; attaching said covered probe to the side wall of the casting vessel so that said probe projects into said casting vessel; pouring molten metal into said casting vessel to immerse said probe in said molten metal; and continuously measuring, by means of said immersed probe, the temperature of said molten metal poured into said casting vessel and in which said probe is immersed; the improvement comprising: attaching said probe to said side wall of said casting vessel through an opening in said side wall of said vessel at a position spaced from the bottom of the casting vessel and below a preselected allowable lowest level of the molten metal which is higher than said opening when the molten metal is received in said casting vessel; and the level of said molten metal received in said casting vessel always being maintained higher than or at least equal to said preselected allowable lowest level of molten metal by pouring in additional molten metal as needed, so that said probe does not contact the molten slag which floats on the surface of the molten metal so that said probe is not eroded by the molten slag which floates on the surface of the molten metal, whereby the temperature of the molten metal in said casting vessel is accurately measured substantially without being affected by the influence of the molten slag contacting said probe or deteriorating said probe.