What is a metal detector and how he manages to distinguish metals ?

What is a metal detector and how he manages to distinguish metals ? In the category treasure hunting more articles and learn more information about What is a metal detector and how he manages to distinguish metals ? Reviews Price Specifications Features Image manuals videos Accessories All this in metal detectors for gold.

What is a metal detector, and how he manages to distinguish metals ?

Metal detectors – are electronic induction tools for detecting metal objects in a neutral or weakly conducting medium, ie, in the ground water, the walls of the wood under the clothing and luggage in foods in humans and animals, etc. The rapid development of microelectronics has made these devices compact , reliable, and very ” smart” . Scope of metal detectors has significantly expanded and, in a purely professional and military applications , has come to encompass and entertainment area to which the ” treasure hunt ” in the broad sense of the term .

Metal detector – an electronic device that detects the presence of metal without contact with it ( thanks to exposure to radio waves and the capture of secondary signals) , and, if found , notify the fact of the operator.

Detector is turned on in the search coil creates an electromagnetic field which extends into the environment , whether land , stone, water, wood , and air. On the surface of metal caught in the zone of the search coil by electromagnetic fields arise so-called eddy currents . These eddy currents produce their own opposing electromagnetic fields, leading to reduction of power of the electromagnetic field generated by the coil , which is fixed and the electronic circuit device . Moreover, this secondary field distorts the primary field configuration , which is also detected by the instrument. Electronic circuit metal detector processes the information and signals detection of metal. Eddy currents are formed on the surface of any metallic objects or conductive minerals. Determination of the metal in the object based on the measured conductivity of the object.

What is a metal detector and how he manages to distinguish metals ?

The difference between cheap and expensive models of metal detectors is only in the methods of radio wave radiation and methods of collecting , processing and interpretation of secondary signals. More expensive metal detector can determine with some degree of probability of appearance of the detected metal to extract it , determine its depth , can build up minerals from the soil , and have a lot of different additional features that enhance the performance and efficiency of search results that are absent in the cheap metal detectors.

Depending on the level of service and prices metal detectors can be divided into instruments for beginners, middle-class devices , microprocessor-based equipment and special devices .

Metal detectors for beginners are designed primarily to address the simple search tasks . It is usually dynamic embodiments VLF, i.e. metal detectors that require continuous movement of the search head . The signal occurs only when the head moves over the object. If you head over to stop the metal , the signal disappears.

Metal detectors are of the middle class and the static and dynamic modes

These metal detectors are characterized by high sensitivity and good resolution . They can be equipped with several interchangeable search coils of different diameters (sometimes oval ) . The number of controls comes to 8 , the procedure of setting requires some skill and lasts several minutes. For example , hand ground balancing is to achieve rotation of the corresponding control signal at the same initial raised and lowered to the ground head. Discrimination in such devices are usually multi-stage with a search of all metals . Management completed a quick adjustment button in the handle or on the body. These instruments have not yet microprocessors – hence the abundance of controls .

Microprocessor metal detectors take the so-called decision on the nature of the findings . It is possible , by using the metal detector circuit microcontroller.

Distinctive features of the microprocessor of metal detectors is the presence of a liquid crystal display (or dial gauge ) and a minimum number of touch keys to enter the program . Under the program refers to the set of states of a virtual ( not retired on the front panel) controls. Adjusting these controls by means of the screen and a few buttons. In memory of the detector , most often incorporated several programs to look in different environments : on the beach, in the park, buildings, etc. When searching for a similar device for each finds measured amplitude and phase characteristics , which allows for the classification of findings . Most devices also carry out classification , giving the screen or on the dial indicator result. Shades of the measured parameter ranges from 8 to 190, which allows you to choose and implement its own program memory of the device , just enough for your needs when you search for specific terms. So you can install any scheme of discrimination unwanted finds at your request .

Deep metal detectors to search for large objects ( large object is a surface area of ​​over 400 square meters. Cm ) are available almost all the major U.S. firms .

Increasing the depth in all devices is the diversity of transmitting and receiving coils ( flat ) in the space . The coils are made of two exploratory head rigidly connected to one another post. Thus one reel in the working position of the device is parallel to the ground surface , the other perpendicularly. Dimensions of the coils of about 25 x 40 cm One of the coils emits electromagnetic waves with a frequency of 12-82 kHz and the other receives the reflected signal.

Specialized metal detectors to search for gold nuggets is a task worthy of its own technical solutions . The fact that the detection of gold universal TR / VLF by metal , metal fine particles that may be taken per unit pellet ferrous metals are not detected . Besides gold output is often accompanied by a “black sand ” containing magnetite, as well as a strong ground mineralization . To overcome these effects increases with the operating frequency of 2 to 10 kHz ( with universal devices ) and 18 – 70 kHz ( from specialized to search for gold) and the use of elliptic search heads.