INDUSTRIAL METAL DETECTOR FOR CONVEYOR LINES Russian patent published in 2014 - IPC G01N27/82 

FIELD: machine building.

SUBSTANCE: in an industrial detector for conveyor lines the area of receiving coils is many times less than the area of a metal detector "window". Signals from receiving coils arrive to inlet amplifiers (separate for each coil), from the outlet of the amplifier the signal is sent to a summator, where it is summed with the "compensation" signal, arriving from a digital to analog converter (DAC), which makes it possible to compensate the signal x.x., then the signal arrives to an analog to digital converter (ADC). Data from all ADC, a speed sensor and another receiving coil connected in parallel to the transmitting one, and also data from the scales (optionally) is sent to a unit of a central processor, in which metal presence is detected. Also in parallel to the transmitting coil there is a calibration loop connected, which is periodically closed, making it possible for an instrument to independently perform automatic inspection and automatic calibration. In the considered metal detector the excitation coil connected to an AC generator creates unresolved magnetic field of excitation acting as the investigated object, moving through the control zone.

EFFECT: increased sensitivity of a metal detector and reduced impact of external electromagnetic environment, which causes reduction of quantity of false actuations.

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