Development of Dual Functional Fiber Sensors for Temperature and Chemical Composition measurements

Purpose and goal

Application of fiber optics in metal industry is growing rapidly due to development of robust sensors which can stand high temperature range. More specifically, application of fiber sensors is becoming a routine in many steel plants. Moreover, the use of such tools will also provide the possibility of chemical composition measurement at the same time parallel to temperature measurements. Thus, SWERIM has investigated measurement of both temperature and composition using fiber sensors in a laboratory scale furnace as well as application of plasma cutting torch for technical alloys.

Expected results and effects

The results have shown a high potential of the sensors for temperature and chemical composition measurement of molten alloys e.g.: Successful temperature measurement above 1000 ºC. This has been done through fiber sensors calibration relevant to the recorded temperature by thermocouple. Successful composition measurement for the technical alloys using plasma torch. The obtained results make SWERIM determined to continue research in this field towards development of fiber sensors for in situ measurement of chemical composition of molten alloy for steel industry.

Planned approach and implementation

As mentioned earlier the project was implemented in 3 stages: 1: Application of laboratory furnace to measure both temperature and composition of single, binary and multi component systems. 2: Development of MATLAB code to convert obtained spectral curves to temperature values in the second stage based on Planck’s black body radiation theory. 3: Application of plasma cutting torch to excite the melt elements at high temperature to be detected by the fiber sensors for 4 technical alloys including carbon steel, stainless steel, copper and aluminum.