The magnetometers is called an extensive group of devices intended for change the settings of the magnetic field (e.g., the module or the components of the vector magnetic induction). The use of magnetometers as detectors based on the phenomenon of local distortion of the natural magnetic field of the Earth ferromagnetic materials such as iron.
Found using the magnetometer deviation from the normal local module or vector magnetic induction field of the Earth, it is safe to speak about some magnetic inhomogeneity (anomalies) that may be caused by iron object.
Compared to the earlier detectors, magnetometers have a much greater detection range of iron objects. Very impressive information about the magnetometer it is possible to register a small Shoe nails from the Shoe at a distance of 1 m, and the car is on a distance of 10 m! Such a large range of detection is explained as follows. The analog of the radiated field with metal detectors for magnetometers is homogeneous (in the scope of the search) the Earth's magnetic field. Therefore, the instrument's response to the iron object is inversely proportional not sixth, but only the third degree distance.
The main drawback of magnetometers is the inability to detect them help from non-ferrous metals. Furthermore, even if we are interested in only iron, the use of magnetometers to search for difficult - in the nature there is a wide variety of natural magnetic anomalies of the different scales (individual minerals, deposits of minerals, etc.). However, when the search for sunken tanks and ships such devices apart from the competition!
Author: A. I. Shchedrin