In the article show the basic principles of metal detection, proposed methods for measuring the quantities by which the type of metal can be determined, and methods for improving the accuracy of metal detection and classification. A hardware implementation of a data processing and analysis unit for determining the type of metal has been developed. Digital data processing tools were used for the implementation, which allows to simplify the block design, minimize possible errors and noises during measurement, distorting the final result of the detection and classification of metals. In the modern world people has to deal with a large number of different metals. There is a problem of distinguishing one type of metal from all others. Such a function of metal detectors is called discrimination. Metal Detector Discrimination is a function that allows you to recognize marked objects by metal type and classify them. Modern high-precision metal detectors contain a large number of functional blocks, complex in setting up and use, sensitive to noise and errors during measurement and detecting metal. The task is to design a unit for discrimination of metals that would consist of a minimum number of functional units, required minimum number of settings and could give correct information about the presence of metal and type of metal and will be insensitive to disturbances caused by the noise and errors during measurement. Metal detectors operate on the principle of magnetic field generation and analysis of the feedback signal from a metal object and the environment. The transmitted magnetic field varies in time. The transmitter is made as coil with an electric current of a certain shape, passing through it and obtained from the generator block. The receiver is made as receiving coil connected to the amplification, filtering and processing unit of the received signal. Any metal has the properties of the resistivity and the properties of the inductance. Using information about the phase difference and amplitude between transmitted and received signals, we can determine type of the metal. To find the phase and amplitude of the received signal, the signal from the metal can be divided into two components: quadrature component has the same form of signal as the transmission signal, but is shifted in time relative to the transmitted signal (phase difference); in-phase component has the same form of signal as the signal transmitted, but, the amplitude of the received signal changes. Then using this two components find the phase and amplitude of the signal. To increase accuracy of the measurement using “ground balancing” principals, and ferrite calibration. As a result get the block for metal discrimination with simple design, minimum number of setting and good capabilities to minimize noise and errors during measurement. Ref. 12, fig. 8.
This work is openly licensed — share and adapt freely with attribution to the authors and the journal. View license terms ↗
Copyright (c) 2019 Олександр Володимирович Цимбал (Автор)
Today, programming is one of the most actively developing technological areas in the world. Moreover, every year the degree of such development only increases, which…
The article identifies the possibility of using MATLAB and Reaper programs for the analysis of nonlinear systems such as overdrive, on the example of the sound effect…
A possibility has been studied of the process of oxygen transfer to the tissues through the capillaries. The idea of spatially resolved oxymetry to be applied at the…
You may also start an advanced similarity search for this article.
