DEVICE FOR DETERMINATION OF MAGNETIC CONDUCTIVITY OF MAGNETIC DEPOSITS ON SURFACE OF PIPES BY EDDY-CURRENT METHOD Russian patent published in 2019 - IPC G01N27/72 

FIELD: physics.

SUBSTANCE: invention can be used for nondestructive testing. Technical expediency of the invention consists in the fact that the eddy-current monitoring device of the specific electric conductivity of the magnetic deposits on the surface of the pipes contains a generator of rectangular periodic current pulses with a period Te, selected from the condition T_e≥3R_eμ₀(δⁿ_mσⁿ_m+δ_d^mσ_d^mμ_r^m), where δⁿ_m and σⁿ_m – nominal values of metal thickness and conductivity, δ_d^m, σ_d^m and μ_r^m – maximum values of thickness, specific electric conductivity and magnetic permeability of deposits, μ₀ – magnetic constant, eddy current sensor with exciting coil, radius R_e which is selected from condition 3(δ_mⁿ+δ_d^m)>R_e>1,0(δ_mⁿ+δ_d^m), where δ_mⁿ and δ_d^m – nominal and maximum thickness of pipe wall and deposits, respectively, magnetic flux meter and measuring coil, output of rectangular pulses generator is connected to exciting coil of eddy-current sensor, measuring coil and magnetic flow meter through amplification units and ADC are connected to microcontroller, to outlets of which are connected indicator of thickness of deposits and indicator of relative magnetic permeability of deposits, is also provided with a simulator, two units for normalizing signals of the measuring coil and a simulator, a unit for comparing values of said signals and an electrical conductivity indicator, wherein the input of the simulator is connected to one of the outputs of the microcontroller, the output of the simulator is connected to the first normalizing unit, the output of the amplifier of the analyzed signal is connected to the second normalizing unit, outputs of the first and second normalizing units are connected to a comparison unit, the output of which is connected to the electric conductivity indicator.

EFFECT: possibility of determining deposit structure.

1 cl, 6 dwg