The necessary fixtures and tools
In addition to the metal detector still needed some accessories and tools. They will help to remove the item found, to lay for further carrying to document the findings.
- First, you need a sharpened shovel. It is very important not to forget about sharpening the blade of the shovel prior to each search with a metal detector, because digging have quite a lot. So would have saved time, effort and supported the good mood during a search.
- Secondly, we need a probe. The probe consists of a smooth steel rod with a diameter of about 5 mm with rounded end. Probe length should not to exceed 40-50 cm, otherwise it will interfere with the carriage. The probe is usually used to determine the location of the subject beneath the earth.
- Thirdly, the right backpack-case of water-repellent material for metal detector to protect the device against rain and mechanical damage during carry. It is best to backpack-case still had pockets for additional hardware.
- Fourthly, you need a sharp axe or pruning shears, because often the excavations interfere with the roots of trees or dense vegetation.
- Fifthly, the box finds, as small and fragile finds not have to throw my pockets and backpack. Very convenient for these purposes plastic boxes for fishing tackle.
- Sixthly, you need a torch, spare batteries for both flashlight and metal detector, headphones. Last, it is desirable to use when searching places except where you have more people.
- Seventh, the right tools for documenting: camera, Notepad, card, pen, pencil. It would be useful to record the time of occurrence of findings details of the excavations in Notepad, and place map. Need and flags white, red flowers, pegs, rope, etc.
- Eighthly, need a first aid kit: on-duty tools, such as plaster, hydrogen peroxide, iodine, aspirin, pain medication and activated coal, mosquito repellent.
- Ninth, it will be very useful oilcloth 1.5 x 1.5 (or 2 x 2) m. it it is convenient to grind it is taken out during the excavation of the ground lead in the resulting layer the clarifying values.
- And, tenth, to properly dress, to have gloves and a hat. The clothes must be durable. Best camouflage cloth. Most the main thing in the clothes of a search engine is of course comfortable shoes, because you will have a lot to walk. Shoes should be leather and thick soles. Good option is hunting shoes or boots for backpackers, which can buy only in specialty stores. You can take the most ordinary garden cotton gloves, rubberized on the one hand, because you will have to dig in the ground, not only with a shovel, but with his hands. In some cases (for example, in case marshland or rain) may need a rubber boots.
The search rules
It is useful to remember a few rules search:
- Rule 1. There is a strong dependence of correct identification from the speed of movement of the coil and its trajectory. Discrimination deteriorates when very fast, very slow or uneven speed.
- Rule 2. Observed best quality of identification, when the coil to promote with small amplitude just above the center of the target.
- Rule 3. If over the target there is a difference of ground level, worsens the identification of the object. It is necessary to reduce the amplitude of the stroke of the coil and try to scan from another angle.
- Rule 4. It is very important to hold the coil as close to the ground. Not it is worth to sacrifice the depth of the search at the expense of scan speed.
- Rule 5. If one side of the device shows that in the earth is the object of non-ferrous metal, and the reverse movement - silent, then move the coil perpendicular to the original direction. Perhaps there will be signal stability and precise identification of the object.
- Rule 6. If the scanning device indicates that in the ground is the object made of metal, and the exact identification of the object is impossible, to ignore these signals is not necessary. In this case, you need to determine the exact the location of the object, to level or remove the upper layer of soil over the center of the object and re-coil from different angles - level the signal will increase, and identification will be more accurate.
Discrimination in the search
First, consider the necessary terms and definitions.
Discrimination - the device's ability to distinguish between various metal objects composition. The ability of this is:
- in the reaction (e.g., a beep) on some objects;
- in the absence of reaction to other objects.
Discrimination is typically configured by the regulator of the level of discrimination that sets on which object will be the reaction. The level of discrimination is simple (computerizing) the instrument corresponds to the conductivity of objects from which device gives the reaction of.
Small objects can be arranged in the following sequence depending on their conductivity: nails -> foil -> Nickel coins -> tabs from cans -> gold jewelry -> tube -> copper coins -> silver.
Therefore, the relevant regulators calibrated in such terms.
In computerized devices a whole range of objects is divided into segments (up to 190 segments), each of which can be set to respond; ignore.
Setting in this case is performed in the learning mode - directly to the coil valuable and harmful objects.
Band discrimination - ability to set a custom reaction to certain objects for computerizing devices, for example, to force the device to respond to Nickel coins and ignore the reeds and cork.
Implemented the introduction of the second regulator discrimination that specifies the position additional range discrimination of objects.
Consider the question of discrimination on the example of the metal detector Tracker IV, which the control for setting the level of discrimination and the toggle switch (full/all metals/tone).
Modes of operation of the discriminator in the detector Bounty Hunter Tracker IV selected via a 3-position toggle switch:
"Tone Discrimination (tone discrimination)/"All Metals" (all metals)/"Full Discrimination mode" (complete discrimination).
Mode 1. All metal regulator discrimination has no effect. All metals emit sound of the same pitch.
Mode 2. "Total discrimination" - the more spin (clockwise) the regulator, the higher the range of discrimination and more metal debris will be screened out.
If you set discrimination to get rid of strong vodka caps, aluminum foil, etc., virtually cease to show up and Golden rings, and Nickel alloys.
Mode 3. "Tonal discrimination" - used selection in tone mode, the metal detector will split the target into 4 classes.
- Class 1. Not emit any tone iron and steel objects.
- Class 2. A low tone indicates that the found gold or Nickel.
- Class 3. High tone means discovered copper, silver or brass/bronze (modern coins).
- Class 4. Broken tone will indicate that the found object, most likely aluminum cover, foil or a piece of aluminum wire.
You should use mode only "Tonal discrimination" in the presence of a large amount of metal debris in the ground. In a more clean from debris the field is justified to use the mode "All metals". Without discrimination depth detection of the detector more.
The depth of detection
Search depth is the most important parameter of the detector.
Oddly enough, but none of the avenues of foreign firms-manufacturers indicates such an important characteristic of the detector as the depth of his action. This is because it depends on many factors:
- the soil type;
- search environment;
- the material of the object;
- the size of the coil;
- the status of the power source;
- experience of the operator;
- the degree of discrimination;
- the use of headphones, etc.
The better (more expensive) metal detector, the bigger the distance it defines larger objects. But still everything has its limits, and even the best devices can't feel a 20 litre canister more than 2 m in the air.
When the subject is in the earth, the conditions of his finding in most soils deteriorate. On some soils the coin (the same 5 COP.) sometimes impossible to detect even if it's just sitting on the surface.
Many devices (more expensive) to a large extent supersede the the influence of soil, but the depth of detection will be less than in air. Much prevent when searching for some of the minerals of the soil, common in places finding gold nuggets - magnetite, chalcopyrite, etc., which give a false signals (like metal), greatly reducing the efficiency of the search.
Pulse detectors are less prone to the influence of minerals soil. The depth of their action in the land and salt water compared with the most common VLF-metal-detectors and comparable to the distance detection of the same object in air.
Finally, there are devices with spaced coils (TM 800 TM 808, Gemini-3, SH with depth multiplier, etc.), the depth of which at large sites reaches depending on the soil type from 1 to 4 m. Their advantage is that they do not react to small objects the size of a coin: tubes, nails, pieces foil constituting the metal debris.
Training search for beginners
Before real output in the field in search of coins, rarities and other valuable finds recommend beginners to start to find many well-known items from the black metal (nails, bolts, tools, etc.) and nonferrous metal (a piece of foil, the cap from the bottle, jewelry and some coins). Scan them the metal detector on the air, to learn to recognize and remember the model signals. If you are a first time holding the detector, such preliminary tests are very important.
In the same way, you can examine the settings and different modes of operation the metal detector. The most important of these "Discrimination", "Sensitivity" and how they affect the efficiency of the device.
Also, try to build your own test site. Bury several well-known subjects, at a depth of from 5 to 20 cm at least 40 cm from each other. Accurately mark the locations where the buried objects. These the tests can be repeated on different types of soil, for example, in the clay ground loose soil, sand. Experiment with a metal detector on the ground, constantly listening and learning signals issued them.
During the practical work on the test site you will learn faster to determine the exact location and depth of objects, and will also understand as the properties of the soil affect the depth of detection of objects.
In order to better hear the change in sound signal, and use headphones be attentive and focused on the task at hand.
Author: S. L. Dubrovsky