Whether in a professional setting or for the detection of treasures on the amateur side, we all had the opportunity to use or see in action a metal detector.We see that it is a very simple device, but then, how does it manage to detect anything?
An indispensable accessory for the search for old and precious objects, this device is used for both leisure and security trades, not to mention its ecological aspect, since it allows to clean up the land of its metallic waste. Let's learn the inventory of what a metal detector, and discover how this object created in the early 20th century.
What is a material detector?
The material detector is a compact electronic device allowing us to locate specific materials in a precise place. Depending on the elements to be detected, it can be of different types. A metal detector, for example, is used to check for the presence of metal pipes or beams behind a partition.
Likewise, a voltage detector searches for cables and other electrical wires, and a wood detector identifies wooden beams and joists.
A material detector can also be universal or "3-in-1", thus combining the functions of metal, tension, and wood detection. The most versatile devices are not necessarily the most efficient. Note that for a device of this type, the quality resides above all in the surface covered and the depth of detection, the most successful models being able to spot obstacles about 10 cm deep.
What is a metal detector made of?
When we look closely at one, we see that a metal detector consists of only 3 parts: the housing, the rod, and the detection disc. As you can imagine, the control unit manages all the electronic part of the device and coordinates its action. This often has a screen, especially in the latest models, ideal for a clear display of data, and also a speaker, to emit sound signals depending on the metal found and its depth.
This is typically what we will see in the movies: a strange sound, beeps, and suddenly bravo is the treasure!
After the case, there is the cane, which just allows the user to stand during the search. The cane is, therefore, nothing more than a piece of plastic, carbon or other material, without any internal technology.
The most important element, the one that makes the detection, is the one found at the end of the cane and which gave the nickname "frying pan" to the detectors. The technical name of the element is "detection disk". It is he who scans the ground, detects the metal, and informs the case of the depth of his find.
Measuring the Depth of a Metal Detector
It is not easy to know the real measurement depths of a metal detector. This is something that involves several factors, the main one being the technology of the detector used. This simply means that today's metal detector technology can detect a metal object at a greater depth than metal detectors five or ten years ago.
Apart from this determining factor, other important elements must be taken into account, in particular: the type of soil, the relationship between the dimensions (thickness, height, length, width) of the objects and their depths on the floor.
How does a metal detector work?
All of this brings us to the real question: how does a metal detector work? The principle of detection is based on the phenomenon of electromagnetic induction, highlighted by Michael Faraday in 1831. the principle of electromagnetic induction for detection is very simple: an "active" coil in the detection disc creates a field magnetic.
If a metal object is close to the disc, it will "cross" the magnetic field and generate an electric current. We will thus be able to determine that there is an object close to the disc by measuring electric current.
Thus, the most widespread metal detector models (called VLF) consist of a minimum of 2 coils: a transmitting coil and one (or more) receiving coil. The first coil emits the electromagnetic field, to which buried or hidden metal objects are subjected, thus creating a disturbance in said field, picked up by the second receiving coil.
This loop is then processed by the device, and in particular by the control unit so that the detector can emit a visual and audible alert for the attention of the user.
However, there is also another kind of detectors, called pulsed induction. These are more modern than VLF, but they are above all much more powerful, and reserved for in-depth research. Consisting of a single-coil, the device sends a powerful pulse in the latter, which generates a magnetic field, before finally collapsing after a few seconds, then causing a current peak called "return pulse".
Therefore, the process is repeated in a loop, and the detection of a metal object is determined by the duration of this return pulse, disturbed by the magnetic field of the metal encountered.
What Can You Find with a Metal Detector?
We have found many (old) coins and utensils. My neighbor has found things in the Netherlands in recent years such as; buttons, weights, leads, rings, thimbles, buckles, tokens, wax stamps and many coins (Check our best metal detector for coins guide). It is also regularly turned on when someone has lost a wedding ring again and it almost always comes up successfully.
The real professional works very meticulously and consults archives, maps, aerial photos, museums and information with old people. Then you also have a greater chance that the penny will turn your way. You regularly read in the news that another beautiful treasure has been found by someone who has been working with his metal detector.
In that respect, the feeling of winning in a casino will be almost the same.
How deep can it reach and how to adjust it?
Roughly speaking, the real capacity of a metal detector depends mainly on the technology integrated into its system. Depending on the model, it can range from five to twenty meters for the most advanced. Manufacturers today equip their products with innovations, much more effective than the specimens of a decade ago.
To start handling your device well, first, adjust the sensitivity level of the disc. By setting it to the maximum, you will be able to identify small objects.
Then, you also have to configure your device on the type of metal to identify. In this way, your searches will be more precise and you will save more time as a result.
Are you a beginner and looking for some valuable working tips and tricks for metal detecting? Why don't you read out guide for beginners tips and tricks for metal detecting, beach metal detector and metal detector choice for beginners. Also check kids metal detector if you are looking for a detector for your kid.
There are different types of metal detectors for various uses. You need to find the best detector according to your needs. I hope this guide helps you to understand how does a metal detector works and some other information.