The iron and steel industry presents a number of challenges to the instrumentation vendor, particularly for temperature/process monitoring applications. Ranging from applications where temperatures are simply too hot for contact measurements to those with extreme electromagnetic interference from arc furnace smelters and applications having many hundreds of temperature measurement points. Harsh environmental conditions with corrosive gas and excessive ambient temperatures all contribute to the design tolerance required from instrumentation in these environments.

For more than five decades, YAMARI has been recognized as a quality supplier of temperature sensing products, including thermocouples, platinum resistance devices and Thermowells, to major steel industries in Japan and overseas.

Hot Stove Dome Thermocouple

The measuring atmosphere is very harsh in high temperature, high pressure and high steaming velocity, sensor must have the following features and YAMARI provides the same:

  • High Quality SIC Protection Tube, SIC protection tube with superior bending strength, porosity and oxidation resistance.
  • Sealed Structure on T/C wire
  • Long Service life Structure of Type R Thermocouple

Spring Loaded Thermocouple for Blast Furnace

As you know, in evaluating the service lifetime of a blast furnace, accurate monitoring of the erosion profile of the hearth bottom surface is a critical factor. Of the various methods available, thermocouple measurements are known to provide the best estimate of the erosion profile and the two point method, because of the high accuracy it allows, is most common employed.

In order to cool the hearth bottom refractory in a blast furnace, a stave cooler is installed in between hearth bottom refractory and iron shell, and in order to have a higher cooling efficiency, ramming material is filled in between stave cooler and heath bottom refractory, and in between stave cooler and iron shell. As a result of the cycle of expansion and contraction due to variation of temperature, some clearance gap is made in between stave cooler and ramming material. In order to bridge this clearance gap, some heavy oil paste is filled. However, if this heavy oil paste comes into the sensor, spring capability of the sensor becomes unable to function.


  • This thermocouple makes a solution to the surface contact problem which keeps the thermocouple tip pressed solidly against the carbon brick even under the cycle of expansion and contraction due to variation of temperature.