The use of thermoelements is a commonly applied method in industry and engineering. It provides a wide measurement range of temperature, a direct voltage signal from the transducer, low cost of the thermoelement, and its resistance to many unfavorable factors which occur in an industrial environment. Unfortunately, thermoelements may not be resistant to interferences of a strong electromagnetic field because of the nature and design of a transducer. Induction heating is the most commonly used type of heating, at present, for metals. In order to guarantee the correctness of the carried out heating process, it is essential to control the temperature of the heated element. The impact of a strong electromagnetic field upon the thermocouple temperature measurement of the inductively heated elements has been analyzed in this paper. The experiment includes dozens of measurements where the following parameters have been varied: frequency of the current which feeds the heating inductor, power supplied to the heating system, geometry of heat inductor, and the charge material and its geometrical dimensions. Interferences of the power-line frequency have been eliminated in part of the carried out measurements.
The paper presents the analysis of the process of casting functionally graded composites under alternating electromagnetic field. The process utilizes the effect of electromagnetic buoyancy on nonconductive particles of the reinforcement in the conducting liquid (melted metal). The authors analyzed the possibilities of homogenizing the distribution of electromagnetic field in such a way as to obtain the desired direction of electromagnetic buoyancy and at the same time minimize the stirring of the molten metal, which makes it difficult to receive the optimal distribution of reinforcement in the casting. The suggested solution was to use the conductive elements of the mold to move the nonuniformity of the electromagnetic field outside the casting and a parabolic inductor to smooth the field distribution in the casting.