Research On Optical Fiber High Temperature Testing

During smelting steel and iron, the temperature of molten steel and liquid iron is one of the most important parameters in steel trade. At present, its temperature measurement is extensively adopted consumptive thermocouple in the world, but adopting consumptive thermocouple has the following problems:(1) Every thermocouple can just be used for one time, so the expense is very high.(2) After every measurement finished, the thermocouple must be replaced. So it is difficult to realize automation.(3) It can not measure the temperature continually or in a high frequency. Now , the consumptive optical fiber radiation thermometer is a new methodfor the temperature measurement of the molten metal. Its accuracy of the temperature measurement is identical with that of the consumptive thermocouple. It can totally take place of the consumptive thermocouple.In this text , the principles of the radiation temperature measurement are related in detail. And some basic theories and the law on the black object radiation are included.This text relates the colorimetry in detail and specially explain its advantages. The colorimetry can greatly lower the blast-off rate which influence the result of the temperature measurement. Under the best term, the influence can decline to zero.This text also introduce some optic-electric colorimetry thermometer in detail by different classification.The design of this system can be divided into 3 parts: the structure design for detector ; optic signal transform into electric signal; convert signal into data and display . We stretch a consumptive optic fiber into the molten metal and take the light signal from it, then transform the optic signal into electric signal and amplify the signal. Send the signal into SCM , use the SCM to convert the signal into data and display the true temperature of the molten metal.Considering that now the consumptive thermocouple measurement method is widespread in the world, and the technique is comparative mature . So the thermocouple technique has very high reference value to our system , and accordingly, in this text, we give an example of thermocouple to make a contrast with the consumptive optical fiber radiation thermometer.In conclusion, the consumptive optical fiber radiation thermometer can overcome many defects of many other method of temperature measurement. Its accuracy of the temperature measurement is identical with that of theconsumptive thermocouple. At the same time , it can reduce the expense of the temperature measurement greatly. It will spread not only in the steel and iron industry but also in the foundry and automobile.