FIELD: measurement.
SUBSTANCE: invention relates to control of physical properties of articles and materials and can be used to detect areas with anomalies of hardness and other physical and mechanical properties of the surface of articles made from ferromagnetic materials, in particular steel sheets, rails, pipes, rods. Device for determining the uniformity of mechanical properties of articles made from ferromagnetic materials and detecting zones with abnormal hardness therein includes a sensor comprising at least one exciting coil (EC) connected to a source of direct and inverted current pulses, at least one measuring coil (MC), having a strong electromagnetic coupling with EC, as well as a U-, Π-, C- or E-shaped core, on which EC and MC are located, and forming a magnetic circuit with a monitored object (MO), wherein the EC and MC functions can be combined in one coil; source of current pulses, which performs periodic inversion of generated pulses, leading to corresponding inversion of direction of currents flowing through EC, a measuring unit connected to the MC, which analyses signals corresponding to at least one direct and at least one inverted current pulses flowing through the EC on each investigated section of the MO, wherein the measuring unit further comprises a unit for converting the received signals from the time domain to the frequency domain and a spectrum analyser (SA) connected in series, wherein amplitudes of both high-frequency and low-frequency components are measured in the spectrum of each received MC signal, based on the analysis of these components, the influence of interfering factors is suppressed and hardness of the test object is determined.
EFFECT: ensuring the required measurement accuracy, increasing the control efficiency and, as a result, the possibility of using the device for determining the uniformity of mechanical properties of articles made from ferromagnetic materials for controlling metal products for the presence of hardness anomalies in the production flow.
1 cl, 13 dwg
