When stainless steel is melted in an arc furnace the temperature of molten steel at the final stage of oxidation period reaches 1800-2200. As an expendable immersion thermocouple which measures such an ultra high temperature W/Re expendable immersion thermocouple is recently on sale. But, this thermocouple is pretty expensive. The writers manufactured expendable immersion thermocouple noticing to W-Mo expendable immersion thermocouple element. We confirmed electromotive force by a wire method

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... Pd and Pt points and then combined as consumption type expendable immersion thermocouple. After that we made a comparative test of W/Re 5-26 on sale and W/Re 3-25 consumption type of immersion thermocouples. The response of immersion thermocouple is as fast as about 3 sec. and so, there is no problem due to the influence of oxidation and in the point of accuracy, these results are not inferior to W/Re consumption immersion thermocouple. From this, we concluded that it is definitely possible to be utilized for ultra high temperature.