MULTI-ZONE MULTI-FREQUENCY METAL DETECTOR WITH HARMONIC EXCITATION Russian patent published in 2018 - IPC G01V3/11 

FIELD: physics.

SUBSTANCE: multi-zone multi-frequency metal detector with harmonic excitation refers to a device for detecting objects made of metal, which are carried by verified persons through a control space. Multi-zone metal detector contains transmitting and receiving coils installed on one and the other side of the passage, the display unit and the control unit. Determining the location of an object from metal is carried out by dividing the control space between the receiving and transmitting coils into local detection zones and calculating the geometric location of metal objects in the control space based on data on the presence of metal objects in each local detection zone, moreover, local detection zones are formed by parallel simultaneous excitation of each transmitting coil by a harmonic signal of a sinusoidal form of a given frequency, at the same time, for each transmitting coil its own frequency of the signal is established, with simultaneous parallel processing of the signal of each receiving coil, filtering and extracting in it the amplitude and phase of the signals of the frequencies induced by each of the transmitting coils, including determining the presence of a metal object in each local detection zone between the transmitting and each receiving coil.

EFFECT: technical task is to create a multi-zone metal detector capable of determining the location of metal objects in the test space.

1 cl, 1 dwg