METHOD FOR NON-CONTACT SELECTIVE DETECTION OF METAL OBJECTS USING PULSE-RESONANCE-EDDY CURRENT METHOD (VERSIONS) Russian patent published in 2024 - IPC G01V3/11 

FIELD: detection of current-conducting and ferromagnetic objects in magnetically permeable solid, loose or liquid media.

SUBSTANCE: method involves sequential generation of pulses of the same duration supplying the coil in the frequency range from 1 Hz to 1 kHz with filling with pulses of a given frequency in the range of values from 1 kHz to 1 MHz with frequency change in each packet of pulses and without filling, pulses of different duration without filling. Upon completion of the pulse train generation process with filling or pulses without filling, the increments in the duration of the leading edge of the current decay in the coil are measured: after generation of pulse without filling of long duration—T1, short duration—T4, increment of duration of front of decay of electric current in coil after pulse generation with filling with frequency, at which the maximum signal from the object is detected,—T2. Type of metal is determined based on the ratio (T1/T2/)T3, where T3=T4/T1.

EFFECT: high accuracy of determining the type of metals.

2 cl, 7 dwg