Classification of detectors
Classification of modern detectors, sometimes referred to as detectors metal objects or metal detectors, usually performed with several fundamental criteria.
Depending on the complexity and functionality of the detectors can be divided into simple, semi-professional and professional. In modern literature the most common description of a plain, or Amateur, designs, occasionally semi-professional. With the description of some professional devices, the principles of their construction, as well as various methods of conducting exploratory research can be found only in foreign publications.
In addition, in foreign literature, for example, is often cited classification electronic detectors metal objects, based on the evaluation used signal. Depending on which signal is generated and processed in a specific device, the detectors are conditionally subdivided in several categories.
The first group includes devices that work with continuous (analog) signal in resonance or frequency mode. In most met the author designs this signal was sinusoidal form. Sometimes these devices are called metal detectors group FD (Frequency Domain).
The second category includes devices that use a pulse signal with subsequent rating change its parameters in time. Such detectors metal objects are sometimes referred to as devices of the group TD (Time Domain).
In a separate category, you can select different magnetometers. The basis the operation of such detectors is based on the principle of measuring changes the magnetic field under the influence of metal objects.
In addition, there is a very broad category of so-called devices a special purpose. Devices included in this group, it would be correct not be called detectors metal objects, but simply detectors of items since these devices are analyzed anomalies of the electromagnetic field Of the earth, caused by any in the soil subject, including non-metallic. The emergence and further rapid development of these devices were due to the use in the various theatres of war plastic (unpackaged) min. it Should be recognized that the device special appointments are fairly complicated and expensive. Therefore, a detailed consideration of the principles build and design features of such devices are also beyond the scope of the present edition.
It should be noted that in some sources it is possible to meet the classification metal detectors, carried out on the basis of an assessment of the frequency range in which this device works. For example, the devices denoted by the abbreviation VLF (Very Low Frequency) operate in the frequency range from 3 to 30 kHz. The device using frequencies from 30 kHz to 300 kHz, indicated by a reduction in the LF (Low Frequency). For detectors operating at frequencies from 300 kHz to 3 MHz, apply the reduction in MF (Medium Frequency), and for devices with an operating frequency in the range from 3 to 30 MHz is the reduction of the HF (High Frequency).
Author: M. V. Adamenko