Using of multiparameter electromagnetic control methods of materials and products for controlling the electrical and magnetic fields of conductive products, which can be used to determine the strength parameters, hardness, mechanical stresses, temperature, and prevailing impurities, is practical interest. The expediency of using electromagnetic transducers with a cylindrical solid product, because in this case the functional connections between the signals of the converter and the product have been determined in the absence of a mechanical stress, is shown. In the paper, further development of electromagnetic methods and implementing converters in the direction of various practical applications and, in particular, for the determination of mechanical stresses, forces, weight of loads, pressures, moments, etc., is considered. Applying the functional dependences of the amplitude and phase of the specific normalized emf of the transformer converter with a cylindrical ferromagnetic product, amplitude and phase frequency methods for determining the mechanical stresses are proposed. The emergence of mechanical stress in the product can result in general to a change in both the values of the magnetic permeability and the specific electric conductivity.
In order to increase the resolving power of a transformer electromagnetic converter when measuring the magnitude of the mechanical stress in a wide range of their variations, the frequency amplitude and phase methods should be used. The essence of both methods is that first, in the absence of a mechanical stress of the product, the value of the frequency of the probe field is defined, corresponding to the maximum steepness of the transformation function, which sets in at 1.5 2%. Both methods were used in the developing of weighing apparatus which having simple conversion function, the design of the elements and high sensitivity to the change in mechanical stresses. These methods also have found application in installations for research of influence of mechanical stresses, deformation on electric and magnetic parameters of products and the samples made of various materials.