Analysis on Technology of Passable Ray and Airtight Cavity Temperature Measurement Applied to Hot Metal

In order to solve the problem of temperature measurement applied to hot metal of the blast furnace under smoggy and dusty environment, an optical and electronic integration sensor which is passable ray and airtight cavity by sheet iron was devised. Based on the sensor, a portable thermometer was designed and made. The detection for temperature of hot metal with the technology has characteristics of noncontact measurement method´s quickness and contact measurement method´s precision. The result coincides with the detection result by means of the thermocouple which is consumed in the blast furnace field test.