Study On The High Temperature Measurement Of Optical Fiber

During smelting steel and iron, the temperature for molten steel and liquid iron is one of the most important parameter. At present, its temperature measurement is extensively adopted consumptive thermocouple in the world, but adopting consumptive thermocouple has the following problems: (l)the stretch for measuring temperature forward for a time, so the expenses is higher. (2)after every time measurement, the stretch must be replaced, so it is difficult to realize automation. (3)it can not continually or in high frequency measure the temperature.Now, the consumptive optical fiber radiation thermometer developing is a new method of the temperature measurement for melted metal. Its accuracy of the temperature measurement is identical with that of consumptive thermocouple. It can totally take the place of consumptive thermocouple.In this text the principle of radiation temperature measurement is related in detail. There is included sonic basic theories and the law on the black object radiation.This text relates the colorimetry in detail and specially mentioned its 'advantage. The colorimetry can largely lower the blast-off rate which influence the result of temperature measurement. Under the best term, the influence can decline to the zero.This text is detailed to introduce some photo-electricity colorimetry thermometer.After these introduction is over above the article just enter myself designed scheme: use a consumptive optical fiber to take the light signal from the molten steel, and convert to a series of data by a thermometer system, then use the software method, and finally work out the true temperature of the molten steel.Here the software method use firstly the least squares method, then proceed Fourier Transform which convert hour field to frequency field, establish the relation of wave-length and power spectrum (or energy spectrum). According to the relation established, it can work out the most difficult measurement thing in measuring temperature formula : B (the ratio between the light spectrum radiation bright both selected wave-length, namely theratio between energy. ). Finally the temperature of the molten steel is begged out.Now that it is widespread to measure the temperature of the molten steel with consumptive thermocouple. This is the comparative maturity on the technique. Using thermocouple to measure the temperature has very high reference value, so this text explains an example in contrast with the consumptive optical fiber radiation thermometer.Consumptive optical fiber radiation thermometer can overcome the defects in many method of the temperature measurement. Its accuracy of the temperature measurement is identical with that of consumptive thermocouple. It can reduce lots of costs of. the temperature measurement. It has very good ratio of performance to price. It will spread not only in the steel and iron industry but also in the field of foundry and automobile.