A metal detector that takes you to great depths. Depth of detection Ground EFX MX400. The best professional metal detectors
When I had Chinese in my hands, I came up with a check for him. I was wondering what is the real depth of detection of a coin in the ground with this detector. Then I decided to conduct the following experiment.
I took a standard coin - 5 late Soviet kopecks. He took out a whole pyramidal piece from the ground 25 centimeters high. At the bottom of the hole formed at the same time, he laid flat a coin. Then I thought about it and decided that sticking it into the wall would not be a bad decision. Therefore, 5 kopecks. stuck at a depth of 25 cm in dense soil. Then he returned the pyramidal piecelandin place.
What did he do? I brought the experiment as close as possible to the natural conditions in which there are thousands of coins we dig.
But, in order to determine the quality of the search for the metal detector under test, I took mine. Since these devices belong to the same class () and have DD coils of almost the same diameter, it will be interesting to see the reaction to one coin from two different (according to the manufacturer) detectors. This, in my opinion, will enable us to fully appreciate the quality of the definition of a penny in the ground by the Ground.
I filmed this entire test, so my reader has the opportunity to see it right now.
And so: I took the 400th Ground, built in the same place, and with a sensitivity of 7, in the “all metals” mode, I began to search for the just hidden coin. The readings of the device were thrown either in color or in black - it was not digging. Then I increased the sensitivity to the maximum. And the MX400 began to respond to everything.
I summarize. Ground EFX MX 400 5 kopecks of the USSR at a depth of a quarter of a meter voices it not dug signal.
Then I tried with my B-5 to find the buried coin. The device voiced the tested target in the same way as the Ground - now in black, then in color. Not digging. The only thing: the “bird” worked more stable than the four hundredth one - it didn’t phantom for everything indiscriminately.
Outcome.
Ground MX 400 sees not a small coin (5 kopecks) at a depth of 25 centimeters, but not a dug signal. Yes, it shows that the target is deep and if the digger does not yawn to look at this parameter, then he may decide to dig such a target.
In almost no description of MD you will see the exact number of the depth to which this metal detector “sees”. This is a very conditional parameter, and here's why.
In chapter "The main types of finds" We have shown that a metal detector can detect objects that are completely different in size, shape, and composition. Add to that various conditions search, and the principle of operation of the device (article "The principle of operation of MD") - and get already several reasons that may affect the depth of detection of the desired items.
Here are the main ones:
1.Goal dependent options- size, shape, chemical composition, location relative to the coil, condition
2. Parameters depending on the metal detector- MD type, sensitivity level, discrimination setting, operating frequency, coil size, shape and type, batteries.
3. Parameters depending on environment – soil moisture, soil mineralization, the influence of electromagnetic interference from power lines and other devices.
4. Operator dependent options.
Let's look at these reasons in a little more detail.
1.1 Target size
It follows from the principle of operation of the device that with an increase in the size of the target under the coil, the depth of its detection increases.
For example, according to the specification of a domestic device AKA "Signum SFT 7272", the detection range of a coin with a diameter of 25 mm is 45 cm, a tin can - 100 cm, a soldier's helmet - 125-140 cm, large objects - up to 250 cm.
At the same time, the measurement data are always given for air, since the soil itself has a great influence on the readings of the device (see below).
On the Internet, you can independently find the results of measurements of the detection depth of one or another MD. But do not forget about other parameters that affect the final figure - for example, the settings of the device itself.
1.2 Target shape
Targets of different shapes reflect the signal from the coil in different ways. The device will detect a more correct shape of the target at a greater depth.
By the way, when searching for a beach, chains are very rare. If the chain lies in expanded form, the device "sees" each of its links as a separate target. Therefore, a chain can be found only if it lies compactly.
1.3 Chemical composition
Objects made of different metals are detected by a metal detector in different ways. key value here plays the electrical conductivity of the metal. The larger it is, the better the response from such a goal.
However, a large object made of low-conductivity iron coated with rust oxides often gives a signal as if from a non-ferrous metal. This feature due to the properties of iron oxides. Recognizing such a goal is not easy. I recommend estimating the target size in static mode. Sometimes it helps to dig with a shovel and slightly raise the clod of earth - this slightly changes the position of the target in the ground and destroys phantom signals from oxides.
1.4 Positioning the target above the coil
In this case, the surface area of the target is important, the larger it is, the deeper it is possible to detect the target. For example, a coin lying on its edge in the ground is much more difficult to detect than a coin lying flat.
1.5 Target status
The more time spent by a metal object in the ground, the more its surface is covered with oxide films that have low electrical conductivity.
Some exceptions are objects made of corrosion-resistant metals such as gold and silver. However, it is worth remembering that the coins were not made of pure silver - the composition of the alloy also included copper, which is prone to oxidation.
2.1. Type of metal detector
The type of metal detector, or rather the principle of its operation, directly affects the depth of detection of certain targets.
T. n. "deep" detectors can detect a large target at a depth of several meters. At the same time, they are unable to "see" a small target such as a coin. And the usual low-frequency detector for searchers is able to detect a coin at a depth of several tens of centimeters, but will not detect a large target at great depths.
The radiation power of the device also affects the depth of target determination. However, an infinite increase in it does not give a proportional effect due to the same principles of operation of the device.
2.2. MD sensitivity level
If in the MD settings a sensitivity that is not optimal for the given search conditions is set, the device determines the target at a noticeably shallower depth.
The maximum sensitivity set in search conditions that are difficult in terms of soil or interference causes false alarms of the device.
The minimum sensitivity means that the device does not operate at full capacity, and, accordingly, the detection depth drops.
In each case, the sensitivity of the device is set individually. This is where the instruction manual for your appliance can help you…and your own experience.
2.3. Discrimination setting
In modern low-frequency devices, discrimination has a lesser effect than in devices of previous generations, however, it can reduce the detection depth from 10% to 20%.
It is not for nothing that experienced search engines use discrimination only in difficult search conditions, and in cleaner areas they prefer to walk in the “all metals” mode.
2.4. Operating frequency
Modern metal detectors mainly have one operating frequency (from units to tens of kilohertz), however, modern devices (companies Minelab, A.K.A.) can have several fixed operating frequencies. Professional devices allow you to transmit several independent signals at different frequencies at the same time.
A high operating frequency is preferable when searching for small targets (for example, pre-Petrine “flake” coins), however, a high-frequency signal decays faster in the ground, so the depth of search by high-frequency devices is lower than that of low-frequency ones.
Low frequency is better for finding larger targets, penetrates deeper into the soil, but cannot detect the presence of small targets.
2.5. Influence of size, shape and type of search coil
Read more about search coils in the section "Additional Coils".
The size of the coil determines its "range", but the larger its size, the worse the device will detect small targets. Small coils are preferred in difficult search conditions - you will always be able to determine the exact location of a particular item.
The standard coil shape is round or elliptical. The ellipse is more suitable for difficult terrain search conditions (grass, forest, etc.) and has a slightly smaller signal cone.
That is, if you need to scout the area, it is preferable to have a round coil with a wider capture area. She will cover in one pass large area, but with more chance of missing the target. For precise scans and methodical search conditions with large overlapping search areas, it is better to use an ellipsoid coil.
Coils are mainly of two types - “mono” and “DD” (the coil body, which contains the receiving and transmitting antennas, resembles the letters “D” symmetrically located relative to each other).
The device and principle of operation of these types of coils will be discussed in the section "Additional Coils".
The advantages of "DD" coils include deeper target detection in difficult ground conditions and better recognition of closely spaced objects due to the shape of the signal. Disadvantages - not as clear as with mono coils, the definition of the location of the target under the coil, especially closer to the edge of the coil. Because of this, large volumes of soil have to be excavated. Also, "DD" coils have worse discrimination against common flat iron targets.
2.6. Batteries
Most metal detectors are powered by batteries or accumulators with a voltage of 6V to 12V.
The battery charge level (except for a critically low one) usually does not affect the search depth, since modern MDs have a built-in voltage regulator.
A small effect on the search depth can only be exerted by the uniformity of the return of the charge by the batteries / accumulators. With uneven discharge, various interferences can occur in the circuits of the device, part of the processor power is consumed to recognize them and eliminate their influence in the overall signal. Therefore, I recommend using proven and reliable batteries / accumulators.
A small article about batteries - in the section “Battery Selection”
3.1. soil moisture
Soil moisture can play a significant role in search depth. The higher the humidity, the higher the electrical conductivity of the soil. At the same time, metal oxides from the object, dissolved in the nearby soil layers (the so-called "halo"), begin to have greater electrical conductivity.
Increasing the electrical conductivity of copper oxides from a coin can increase the depth of its detection. And an increase in the electrical conductivity of a rusty iron part can mask a useful signal from a nearby silver coin that does not have a developed halo due to low silver corrosion.
Plus, it is possible to reduce the search depth in highly mineralized soil by increasing the electrical conductivity in the wet state. The soil begins to "jam" useful signals. This effect is often seen in beach searches on the coast.
3.2. Soil mineralization
Modern detectors have the function of filtering such signals. This is described in more detail in the article. "Rebuild from the ground".
3.3. Influence of electromagnetic interference
Like any other precision electronic instrument, a metal detector can be affected by various electromagnetic interferences, distorting input signals and overloading the electrical and electronic circuits of the instrument itself.
Modern and professional devices are less susceptible to this interference, because they can change the frequency of the output signal and have better built-in noise filters.
If your device does not have these functions, and when searching, it often gives out false information, then The best way calmly continue the search - just move away from power lines or your colleagues.
4. Parameters depending on the operator
The most important factor influencing the depth of the search is you yourself. You can buy the latest professional instrument and find it less than an experienced colleague with a detector for beginners.
Getting the coil wired right above the ground, setting the instrument settings for each specific search location, being able to understand your instrument all come with experience.
The main groups of metal detectors (metal detectors) suitable for searching for coins, treasures, relics
According to the characteristics of metal detectors (metal detectors), which are suitable for searching for coins, treasures, relics, can be divided into several groups. Let's consider them according to the principle "From simple to complex".
Group 1. Simple ground metal detectors.
Price bar from 2500 to 10,000 rubles.
Peculiarities. Designed for beginners, have a small set of functions when searching.
Work principles. To detect a target, one or two frequencies are used, they include discrimination, less often - determining the depth of the target.
♦ small coins "flakes" (coins of the 15th-17th centuries) - 3-5 cm;
♦ large coins, for example, a penny from the time of Catherine II - 15-20 cm;
♦ helmet, ax - 20-30 cm;
♦ manhole cover - 70 cm.
Group 2. Semi-professional metal detectors.
Price bar from 12,000 to 20,000 rubles.
Peculiarities. Designed for people with sufficient experience in search, have a fairly wide range of functions when searching.
Work principles. To detect a target, the use of multi-frequency radiation is provided, they have the ability to operate not only with sound, but also with visual information, i.e. visual information is displayed on the display, where you can see the VDI of the detected object:
♦ if VDI is in the positive zone (it has a “plus” value), then this means that the metal detector has detected a “non-ferrous” metal, and by the VDI value it is possible to determine with an accuracy of up to 70% which “non-ferrous” object is detected;
♦ if VDI is in the negative zone (has a value of “minus”), then this means that the metal detector has detected “ferrous” metal.
Copper and silver coins always give a VDI value close to the maximum values. On different metal detectors, the digital minimum and maximum VDI values \u200b\u200bare different, for example, -10 to +100
or -30 to +50. That is why such devices can be classified as semi-professional.
Depth of detection(depending on soil type!):
♦ small coins "flakes" (coins of the 15th-17th centuries) - 5-15 cm;
♦ large coins, for example, a penny from the time of Catherine II - 25-30 cm;
♦ helmet, ax - 40-50 cm;
♦ manhole cover - 100-150 cm.
Group 3. Professional ground metal detectors.
Price bar - from 20,000 rubles.
Peculiarities. Designed for experienced searchers, have multi-voice discrimination, multi-frequency search range, many manual and automatic settings, i.e. a very wide range of functions when searching:
♦ it is possible to determine the presence of a “colored” object next to a “black” one with an accuracy of up to 80%, which makes it possible to more accurately search in places where there is a lot of household iron debris;
♦ when a signal is detected, visual, digital and audible signaling is used.
Analysis of these indications and makes it possible to determine:
♦ what is found;
♦ what is the depth of occurrence;
♦ What are the dimensions of the detected object.
Work principles. This is a search computer that
fully used digital processing microprocessor signal. It provides search and selection of all "colored" objects located in the investigated surface.
Detection depth (depending on the type of soil!):
♦ small coins "flakes" (coins of the 15th-17th centuries) - 15-25 cm;
♦ large coins, for example, a penny from the time of Catherine II - 30-45 cm;
♦ helmet, ax - 50-80 cm;
♦ manhole cover - 150-200 cm.
Group 4. Metal detectors for searching for gold nuggets.
Price bar - from 25,000 rubles.
Features Designed for experienced searchers, they have multi-voice discrimination, multi-frequency search range, many manual and automatic settings. Almost the entire range of such metal detectors can be classified as professional. They have the frequency to detect even the slightest gold content in any environment.
Gold has quite a characteristic VDI, but very similar to foil (both in sound and visual discrimination). It is very difficult to cut off the foil from gold or find a gold grain in the ground.
Gold metal detectors are designed to pick up the frequency of gold more than the frequencies of all other non-ferrous targets. At the same time, the indicators for finding other “colored” targets remain at a high level.
Group 5. Underwater metal detectors.
Price level - from 25,000 rubles.
Peculiarities. Designed for experienced searchers, they have multi-voice discrimination, multi-frequency search range, many manual and automatic settings. They have a sealed case, headphones. Visually, they do not give out information, only sound.
Work principles. The settings in such metal detectors are designed to take into account not only mineralization, but also the interference created by water, while the interference is different in fresh and salty sea water.
Usage area. Search at the bottom of the reservoir, on the beaches, in the coastal zone.
The depth of detection depends entirely on the search environment.
Group 6. Deep metal detectors.
Price bar - from 22,000 rubles.
Peculiarities. They are designed only to detect volumetric objects located at a depth and cannot find a coin that lies at a depth of several centimeters from the surface.
Features of work. They practically do not have discrimination, that is, when an object is found, it is necessary to dig it out in order to see what is found. This kind of metal detectors are usually used during excavations at the battlefields of the Second World War, where objects can be covered with earth more than 1.5-2 meters.
Detection depth (depending on the type of soil!):
♦ individual coins at a shallow depth - does not detect;
♦ treasure of coins - 1.5-2.5 m;
♦ large metammic objects - 3.5-5.5 m.
Depth coil. Garrett has created a deep special coil for the GTI 2500 universal metal detector. It is significantly inferior in size to the coils of deep metal detectors, but it makes it possible to use one metal detector for all kinds of searches.
Group 7. Pinpointers (metal detectors for pinpointing an object).
Price bar - from 12,000 rubles.
The name comes from English words Pin Pointer (dot pointer).
Features of work. A metal detector for detecting the exact, to the millimeter, location of an object. Such metal detectors do not have discrimination and are used to detect inside walls. Some search engines are used to detect small coins during excavations.
The main purpose of the pinpointer is to indicate the exact location of a metal object at a small search depth (up to 5 cm).
Metal detector detection depth
Metal detector detection depth
One of the most important indicators when working with is the depth at which he can "take" targets. No matter how convenient it is to use, no matter how many functions it supports, the main thing is depth.
The value of the depth of search, which one or another metal detector is capable of, is increasing due to the many myths that the Internet is full of. Many beginners are convinced that the oldest coins can be found a maximum of twenty to twenty-five centimeters from the surface, and any metal detector will be able to find a little thing. Others will try to convince you that they came across a Soviet penny at a depth of half a meter, although their device cannot take the same coin in the air at a height of thirty centimeters from the coil (note that there is often a gap between the coil and the ground surface, so the search depth decreases even more).
That is why it is very important to determine the depth of action of the metal detector that is in your hands. There are some very simple tests for this.
Metal detector depth test
The most effective, but relatively time-consuming, is the “pipe”. With its help, Fisher manufacturers usually determine the depth to which their devices are capable of working. It is necessary to choose a plastic tube that will not be damaged when instilled. Dig it into the ground at an angle of about forty-five degrees. Inside it, something like a “sled” should be placed - a kind of fasteners on which the doors roll in the closet. On these "sleds" you can raise and lower the target, which will allow you to adjust the depth of your device.
If you do not want to spend time creating such a tube, there is an easier test. You will need a Soviet five-kopeck coin, most often used in such tests, and a resealable plastic bag (in which various badges or seasonings are often stored). A layer of earth is dug out with a shovel, from twenty to thirty centimeters, and a bag with a coin is placed at the bottom of the hole formed. It should be remembered that the earth must be removed very carefully so as not to disturb its texture. In this case, the situation of "natural occurrence" will be recreated, and the performance of the apparatus will be closest to the real ones. In addition, this will make it easy to remove the coin, and the metal will not be soiled in the ground.
After the package with the "object" is under a layer of earth, we shave for the metal detector. We turn it on to maximum sensitivity in order to understand how deep it can actually take. In the event that the options provide a function for automatic tracking of the ground balance and additional tuning, turn it off. Otherwise, the sensitivity of the device will weaken somewhat and the indicators of the maximum working depth will not be correct. Then turn on "all metals"
Again, it is this mode that allows you to achieve the most clean results.
For the purity of the experiment, it is also required that the depth at which the sound signals subside is checked. At this level, the discriminator loses the ability to determine the metal from which the found object is made. We will consider it as the maximum depth at which the metal detector operates. It will also be best if the device is turned on at least a meter before the hole. The fact is that on these tests you can check the sensitivity of the device.
Then the next stage of testing begins. Leave the device in direct sunlight for half an hour or an hour so that it warms up well. This will affect the temperature balance of the earth. If the indicators have fallen, or, best of all, they have left altogether, as it is called, “the earth has left”, then the device will not find the coin. The signals will be completely clogged in this case due to incorrect ground balance tuning.
A device that has not passed the temperature test is unlikely to work well. Even if, under normal conditions, the metal detector operates at a relatively large depth, you will have to constantly adjust it during operation to the changed ground balance. In the same case, if you get carried away with the search and forget to do it, then there is a danger of missing something really valuable.
The last group of tests is designed to test object discrimination. In essence, they are almost identical to tests with a plastic tube or bag, but only with the discriminator turned on. You will need to constantly look at the screen or use the headphones to see at what depth the object is identified as accurately as possible (for this, you also want to know the metal of the object that you used for testing).
Do not be alarmed if the search depth decreases: it happens that it is reduced by about half, but this is with bad or old devices.
All these tests will help you determine how deep the metal detector you bought works and imagine what it will be like in the field.
Perhaps the main two criteria by which a novice treasure hunter chooses a metal detector are the cost of the device and the depth of target detection. It's two important factors which are directly dependent on each other.
At the same time, you need to clearly understand that a cheap metal detector, by its nature, cannot have a large detection depth. It has a low cost, due to the fact that it does not use modern developments and achievements, and only old technologies of the 80s are used.
In the current situation, when instrumental search has become widespread, it is very problematic to find a worthy find with the help of a cheap metal detector. And every year this trend is getting worse. The more modern your metal detector, the greater the chance of success.
In a modern metal detector, the main thing is technologies that allow you to search deeper, more accurately recognize metals and ignore interference from the ground. Soil interference is the very cornerstone from which the depth of detection and sensitivity of the device are curled.
Soil interference or why the metal detector does not reach the center of the earth.
With a metal detector, we are looking for treasures and coins in the ground, which is replete with all sorts of interference that prevents the passage of an electromagnetic signal from the coil into the soil. These disturbances are collectively referred to as soil mineralization.
The less mineralized the soil, the higher the depth of detection. Light soils include chernozem, peat bogs, fresh sand. Highly mineralized soils - salty wet sand, soils with the inclusion of ceramics, burnt clay and bricks, with rusty remains of metal and oxides. Mountainous terrain, loam, clay, salty soils - all this should also be categorized as highly mineralized soil.
Today, the main struggle of metal detector manufacturers has unfolded in the field of technologies that compensate for soil interference, since this is the only way to increase the depth and sensitivity of a modern metal detector.
Minelab can be considered the leader in technical solutions in the struggle for detection depth. Over the past few years, Australian scientists have developed and implemented dozens of unique technologies that we actively use now - VFLEX, FBS, BBS, SETA, DVT, AGT, AGT-C, SFT and a number of others, aimed mainly at filtering soil noise.
Choosing a metal detector according to the criterion "Price - quality"
Naturally, the cheaper the metal detector, the lower its detection depth, lower sensitivity, and extremely weak differentiation of metals. And yet, let's try to find a middle ground and choose a metal detector for your needs, based on the "price-quality" criterion.
A metal detector is cheaper than 10 thousand rubles.
Application: As fun, or to collect scrap metal.
Metal detectors from 16 to 25 thousand rubles.
Application: The first step in treasure hunting. Search for coins, treasures.
This group includes entry level metal detectors. They are intended mainly for those who seek to get acquainted with a new hobby for themselves - treasure hunting; or for those who choose a device according to the principle “there is little money, but they really want it. I’ll find a treasure, buy a cool metal detector.”
In this price category, two models of the X-Terra 305 metal detector by Minelab worth 26,900 rubles stand out with their characteristics. and a Whites Treasure Master metal detector worth 23,170 rubles. Maximum detection depth 80-100 cm. Important features:
Detuning from soil interference,
Detuning from electrical interference,
8 and 12 band discriminator,
Polyphony,
tonal background,
The XT305 model uses two detection frequencies - 7.5 kHz, and a high frequency - 18.75 kHz - a unique digital VFLEX technology, the essence of which is the rejection of noisy and noise-immune analog signal transmission circuit, and the transition to a modern digital computer technology. This new development has improved the quality of metal recognition, increased target detection depth and sensitivity.
Killer ASI 250, so they called the new one Treasure Master by Whites. By technical specifications it is much superior to the ACE250, but the price is not inferior to it. The price of ACE 250 is 21,000 rubles, and Treasure Master is 23,000 rubles.
All these technical innovations put X-Terra 305 and Treasure Master metal detectors, though not expensive, into a series of professional serious devices.
Metal detectors from 30 to 50 thousand rubles.
Application: a serious metal detector for treasure hunters.
In this price category, high-tech metal detectors are presented, which are used for professional work. The maximum detection depth of such metal detectors is more than a meter. A good discriminator allows you to distinguish between types of metals and not waste time extracting iron targets.
The X-Terra 705 metal detector is the most popular among treasure hunters. The price-quality ratio allowed it to become the most popular metal detector. At a low cost - 45,990 rubles, the X-Terra 705 has three detection frequencies of 3 kHz, 7.5 kHz and 18.75 kHz, which contributes to the maximum possibilities for detecting both large and very small objects. VFLEX digital technology has made it possible to increase sensitivity and search in the presence of electrical interference, even near power lines. This is a versatile model with a wide range of action, which can successfully search for treasures, coins, jewelry lost on the beach, as well as gold nuggets in mines and mountain streams. A special GEO program allows you to find gold particles smaller than a match head. Treasure hunters use the GEO mode to collect treasures and search for small silver coins - scales. No other metal detector in this class has such features as the X-Terra 705.
Standing out in this category is the new Whites Treasure Pro metal detector with automatic ground balancing (AutoTrac® (Tracking) function), waterproof control box and waterproof coil. The peculiarity of this model is that with it you can search under the water. The cost is 31,590 rubles.
Metal detectors from 45 thousand rubles and more.
Application: The choice of professional treasure hunters.
These are professional metal detectors with modern technical solutions that allow you to find objects at the maximum depth available to modern technologies.
The most popular metal detectors in the treasure hunting community, as you would expect, have the most advanced technical solutions and know-how, on which the depth of detection, sensitivity, and quality of discrimination depend. For example, models: Explorer, E-Trac and modern CTX 3030. These metal detectors are unique developments of Australian scientists, which have no analogues in the world, and use not only information about the conductivity of the metal, but also its inductance to determine the type of target. In addition, they use 28 search frequencies to detect a target, and not just one, like conventional metal detectors. A multi-frequency metal detector in the process of searching examines a target in the ground with a whole range of frequencies, obtaining the maximum amount of information about the object, and thereby allowing you to more accurately determine the type of metal and most effectively compensate for soil interference. These unique metal detectors are able to work steadily both on clay soil and on a salty sea beach, among broken bricks and clay shards.
A good single-frequency model is the XP DEUS model with good sensitivity to small objects, a wireless coil and an original control unit. This model is worth paying attention to.
Note to treasure hunter
What is the frequency of detection of a metal detector and what depends on it? Single-frequency metal detectors, depending on the frequency, are purposefully tuned to large or small search targets. The high frequency of 18 kHz allows you to capture small objects with a size of 1-2 mm. However, the high-frequency signal attenuates faster in the soil, so the depth of detection of objects is somewhat less. A low frequency of 3 kHz detects small objects worse, but electromagnetic waves penetrate deeper into the soil, respectively, the depth of detection of objects is higher. The lower the operating frequency, the deeper the detector can locate the target. Multi-frequency metal detectors with 28 detection frequencies from 1.5 to 100 kHz search both at high and low frequencies, allowing you to combine the best qualities of low-frequency machines and deep low-frequency machines in one device. Working with a metal detector that uses multi-frequency technology is essentially the same as using several single-frequency metal detectors at the same time with different characteristics at the same time.
Feature application of many frequencies and special programs.
Depth of detection
The depth of detection of metal detectors depends on the size of the target: the larger the object, the deeper it can be detected by the metal detector. For example, the average detection depth of modern professional metal detectors with a standard 10” coil reaches 30-40 centimeters for single coins, about a meter for a treasure the size of an army helmet, and up to 1.5 meters for a larger object. You can increase the detection depth by installing a larger diameter coil, for example - 15 or 18”. That allows you to increase the search depth by 30-35%. At the same time, it should be taken into account that such an increase in the detection depth is possible only when using multi-frequency metal detectors. For inexpensive single-frequency models, the increase in detection depth will be no more than 10-20%, due to increased soil interference with the diameter of the coil. A priori, single-frequency metal detectors cope less effectively with soil mineralization than multi-frequency ones.
Finally
When choosing a metal detector, try not to save money. These are one-time costs that are justified only at a certain level. Remember, treasures and coins are not mushrooms, and will not grow again "after a rain on Thursday." Having saved 10,000 rubles, you run the risk of missing an expensive coin or treasure, which is incomparably higher in value than the money saved. Treasure hunting is becoming a mass hobby, and if you don't find your treasure, someone else with a better metal detector will find it tomorrow.
Metal detector detection depth chart
To enlarge the graph, click on the picture.
Underwater metal detector practice and finds.
An underwater metal detector is a special topic. The choice of such devices is not great, but I will talk about one of them, as I know its features well. The main advantage of this metal detector over others is the ability to work in any water, fresh or salty.
Why do treasure hunters need headphones
Metal detector X-Terra 705 video instructions for use
Metal detector X-Terra 305 video instructions for use