They are especially useful when working in places where strong noise
(motor transport, sea surf, Storm River, etc.) drowns the signal from
the device's dynamics. Masking external sounds, the headphones
bring an audible signal from the object directly to the ear. Often deep
objects can not generate a signal enough to sound the speaker, but
in the headphones we can hear it already. This way the headphones
increase the detection depth of the object.
In addition, consuming less energy than the speaker, headphones increase battery life by 70-80%.
Headphones are produced in various shapes, sizes and configurations. It is desirable to have headphones which comfortably sit on a head, not slide and strongly not tight. There must be a volume control for each ear or, at worst, one common. The fact that metal detectors, as a rule, do not have a volume control, because it is not necessary. However, when working in headphones, the volume must be adjusted, otherwise strong signals from shallow or large objects can damage your hearing.
Finally, when working with headphones, the metal detector does not emit loud signals that usually attract unwanted viewers.
In hot weather, you can use lighter headphones from the player, but also with the volume control. The headphone plug has a diameter of 6 mm. If you use headphones from your player, you must use the appropriate adapter to connect them. Don't buy too expensive headphones that are designed to listen to music and play a wide range of frequencies. For detector, the sound quality doesn't matter.
The search coil is an integral part of any detector. It is quite obvious that no metal detector can work without a coil. Less obvious is that the quality of the coil, its type and design will determine how effectively the metal detector solves its task.
In the case of the coil are enclosed, as a rule, two antennas-transmitting and reception. The electromagnetic field emitted by the antenna of the transmitter passes into the environment-soil, stone, sand, water, wood, air, etc. The secondary signal from the object is captured by the receiving antenna, amplifies and informs us about the object in one way or another .
On a design of a coil divide on concentric coplanar, gripping type 2d, coaxial, coils with the posted antennas.
Concentric coplanar reels. This configuration is the most common in modern appliances. It has a high sensitivity, depth of detection and good discrimination.
As a rule, in the casing of such coils two transmitting antennas and one reception, located concentric in one plane are enclosed. The electromagnetic zone of object detection, created by such a coil, has a tapered shape with the highest intensity in the center. Such coils are quite flat and light. In the center they can have a hole, which makes it easier to establish the exact location of the object.
Coils gripping type 2d. In these coils, the transmitting and receiving antennas have the appearance of the letter D, which partially overlap, form a metal-sensitive area of the elliptical shape. This design is less sensitive to soil minerals and at each flapping covers a large area. Usually they use a thick enough wire, so they are heavier than concentric coils.
As a rule, these reels are equipped with devices for the search of native gold. Disadvantages of such coils include unsatisfactory adjustment of iron and difficulty in determining the exact location of the object in the ground. These shortcomings are eliminated in the last elliptical coils of the firm "Tezoro ", which are characterized by high sensitivity, discrimination and pinpojntingom with wide seizure and small weight.
Coaxial reels. This design is used in coils with a diameter of 2.5-10 cm. High requirements to the accuracy of manufacturing make them quite expensive. The transmitting antenna is located between the two receiving antennas.
This creates an electromagnetic field-more or less homogeneous in the density of the flow. They are usually not affected by interference from high-voltage lines. The advantage of such coils is manifested at work on strongly trashy areas where they can detect valuable objects located in close proximity, for example, from a nail or a cork. They also allow you to work near metal fences and poles.
Coils with separated antennas. The antennas of the transmitter and receiver are perpendicular and separated by 1 meter.
They are used in deep instruments, detect large objects at a depth of 4-6 m, but do not react to small objects (the size of a coin).
Pulsed instrument reels. can have one antenna which serves and transmits (at the moment of release of an impulse), and reception (at the moment of absence of an impulse). However more often use two aerials as in this case it is much easier to untie high-voltage output circuits of the pulse generator of current and sensitive input circuits. At impulse devices The sizes of coils can be both standard and large (1x1 m, 2x2 m or a loop in diameter 5-10 m).
All reels of modern devices have electrostatic protection preventing the appearance of false signals (for example, from wet grass). Earlier such protection was carried out by winding coils of a spool by foil, now the internal surface of a casing of a coil cover graphite conductive varnish or inhibitors of electrostatics introduce directly in plastic of a casing of a coil (so -called monolithic coils).
The sizes of search coils of devices VLF/TR vary from 2.5 to 60 SM. Typically, the smaller the coil, the smaller the size of the object it can detect. Large reels are designed to find large objects at great depth, but they can also find relatively small objects (coins, rings, etc.).
The majority of detectors is equipped with a reel from 16 to 23 cm-this is the optimum size for the general purpose of search. These reels are light, have a wide grip and are quite sensitive to a number of objects, detecting them at a considerable depth.
When working on sites with increased content of metal debris, it is recommended to use coils with a diameter of 7-12 cm. They have high sensitivity and resolution and also allow for more precise positioning of the object. When searching for coins, the detection depth in comparison with the standard coil decreases not much (1-2 cm). Because of the small size the speed of processing of a site noticeably decreases, but it is investigated more carefully that increases probability of finds.
The reels of large size (30-60 cm) also react well enough to small objects, but finding their exact location is more difficult than using small or standard reels. They do not give appreciable increase in depth of detection of small objects (coins). Their advantage is manifested in the search of large objects in conditions of low mineralization of soil. For example, when using a standard reel, Spectrum XLT detects a helmet at a depth of 1 m, and with a reel of Blue mach 1500 diameter 35 cm-at a depth of 1.5 m. However, if the soil is heavily digesteded or contains a lot of metal debris, the benefits Large coils are lost due to the need to reduce the sensitivity of the device.
It should be noted that each company produces a variety of reels, which are suitable for devices only this company.
The most cheap coal-zinc batteries. But they have the least lifespan. Works best at temperatures from O ° C to + 40 °c. Most prone to leaks. A little more expensive, but serve longer zinc-chloride batteries. Also prone to leaks. Alkaline manganese batteries have a significantly longer lifespan than the first two. In addition, they are better kept and work better at low temperatures. Although they are more expensive, but in general their use is cheaper than coal-zinc and zinc-chloride batteries.
Nickel-Cadmium rechargeable batteries cost much more. When properly operated, they serve for a very long time, as they can be recharged up to 1000 times. However, because of their "memory effect," they may lose their performance much earlier if they are not exploited properly. "Memory effect " is that the undead nickel-cadmium battery as it would memorize the residual capacity and subsequently not fully charged. To combat this phenomenon requires one or more cycles of charge-discharge, which makes a certain inconvenience in the operation of nickel-cadmium batteries. That's why they stopped using them to power mobile phones.
In this respect is much better nickel-hydride batteries, which unlike NiCd batteries allow charging at any time without the need to completely discharge the battery. However, for efficient operation of the battery it is necessary to carry out 3-5 cycles of charge-discharge of new NiMH battery. For this purpose it is necessary to charge it completely before the first use. We recommend to place the battery before the first use under voltage for at least 12-16 hours. Ideally, 20 hours. It is not necessary to worry that excessively long-term finding of the battery connected to the working charger will cause any harm. The device has built-in protection and changes the voltage according to the degree of battery charge. If the battery is fully charged, the charging stops.
Now you can use the battery. However, try to ensure that when the metal detector is first operated with a new battery, it can be completely discharged. Most likely, you will need 2-3 days of intensive work with detector.
The second charging time must not be less than 12 hours. Ideally-16. Such cycles (full discharge-charging 16 hours) will require at least three. Better if five. These techniques only apply to the beginning of the new battery. You do not need to fully discharge the battery in the future. You will be able to recharge it, regardless of whether it is completely discharged or not. But the implementation of these recommendations will significantly prolong the life of your battery.
If the battery is not used for a long time (6 to 9 months), you should perform the above mentioned actions as if it were a new battery. Only 3-5 cycles of charge-discharge-and you have a fully prepared battery. You will not lose any performance.
The most effective are lithium-ion batteries, which, although more expensive, but have a higher capacity with less weight. In addition, the Li-ion element has a voltage of 4.2 V, a NiMH-only 1.2 v. This means that the Li-ion battery can consist of 2-3 elements (the battery it is called because, besides the element, has also an electronic circuit, protects it from a deep discharge, and short circuit), a NiMH-at least eight. And for batteries there is a rule: the less they have the elements, the more reliable and longer they work when properly operated.
One of the main quality characteristics of the battery is its capacity. It is measured in ampere-hours (AH) or milliamps-hours (mah, 1 ma = 0.001 a) and indicates the magnitude of the discharge current, in which the fully charged battery is drained to the voltage end of the discharge in 1 hour. The higher the battery capacity, the better.
Knowing the capacity of the battery (or rechargeable battery), it is easy to calculate the time of the electronic device. To do this, the battery capacity is divided by the discharge current (load current). As a result we get the duration of continuous work of detector. Usually it is 15-20 hour. For NiMH batteries and 50-60 hour. For Li-Ion batteries. There are standard and accelerated methods for charging batteries. The standard charge is the safest for any battery. If a fast charge is applied, then it is very important that the battery is completely discharged before starting the charge. Chargers that provide a quick charge start charging cycle with the discharge of the battery, in order to then charge it to full capacity. These devices, which have a special electronic charge control scheme, cost more than standard charging devices. However, besides reducing the charge time, their use allows to increase the life of the battery, because the slow charge contributes to the development of "memory effect ". Reservations are not here. Manufacturers, saying that for NiMH batteries this effect is uncharacteristic, cunning. It still takes place, although expressed not as vividly as in NiCd batteries.
Lithium-ion batteries do not have a "memory effect ". It should be noted that lithium-ion batteries are charged with chargers that are incompatible with the nickel-hydride battery chargers.
Despite the high cost of rechargeable batteries, in general, their application is more advantageous in monetary terms, with frequent work with detector in comparison with conventional batteries.
Lead accumulators used in the devices of firm AKA, also do not have "Memory effect " and can be recharged at any time. The drawback of them is the high weight.
The operation and lifetime of the rechargeable battery are highly dependent on the following rules of treatment.
Charge and discharge:
1. Optimum performance of the new battery is achieved only after three to five full charge/discharge cycles! This applies only to NiMH batteries.
2. The rechargeable battery can be charged and discharge hundreds of times, but it gradually wears out. If the duration of work is significantly reduced, replace the battery with a new one.
3. The unused charger must be disconnected from the power supply (AC or onboard vehicle network).
4. Do not leave the battery connected to the charger for more than 24 hours, as the recharge shortens its service life.
5. If the fully charged battery is not used, it will eventually discharge
6. To increase the duration of the nickel-Metallgidridnogo battery, it is necessary to carry out the full discharge from time to time, leaving the appliance on. Attempts to discharge the battery in another way are not allowed.
Tools for retrieving finds
To extract the finds used various tools-knives, screwdrivers, scoops, sappers and garden shovels, probes, borax, etc.
Some of these tools are conveniently fastened on the belt. The authors recommend to use for this purpose an army belt of manufacture of the USA which now is possible for purchase in Russia in shops selling tourist equipment and arms. This strap is wide enough, durable, hard, comfortably fastened and adjustable.
Screwdriver. For extraction of coins from depth of 5-10 sm The usual flat screwdriver is applied. To avoid damage to the coin, it is recommended to whittle sharp edges and angles.
Knife. It is used for cutting of turf stoppers, crushing of solid or frozen ground, cutting of thin roots, interfering with work, etc.
The length of the blade should be 15-18 cm, thickness 4-5 mm. Rubber or leather handle. The selection of knives is now quite large, and you can choose a suitable model to your liking. It is recommended to cut off the end of a case that the ground falling with a knife in a cover, gradually from it poured out.
Scoop. For extraction of coins, lying on a small depth (5-10 sm) Sometimes the garden scoop is useful. The end of it can be sharpened so that he can cut the turf. The scoop should be quite rigid and comfortable at work.
Probe. The probe is made of a long thin (3-4 mm) screwdriver, the end of which rounded. Piercing a pound probe, you can easily find the exact location of the coin.
To protect the coin from damage to the end of the probe, you can apply a layer of epoxy resin.
Probe. If the ground is enough malleable, for check of deep find it is possible to use successfully a probe made of a bar of hardened steel in diameter 8-10 mm and length 130-150 SM. To the top end welded a transverse handle, and in the bottom part screwed a conical tip, the diameter of base of which on 2-3 mm more than diameter of a rod. Piercing probe pound and touching them to the find, you will learn to recognize the material from which the find is (metal, bone, ceramics, glass, paper, wood). The probe saves time on digging finds, which can be a rusty bucket. Unfortunately, not always the pound can be pierced by 1.5 Mefa probe. In this case, the drill can help.
Bur. When deep objects are found, the metal detector is not able to recognize the metallic, black or coloured object. To determine the type of metal, it is not necessary to dig a pit depth of 1.5 m. You can drill a hole with a diameter of 4-5 cm by hand brown, lower the cylindrical coil with a diameter of 2.5 cm and, using discrimination, determine the type of metal, and then take The solution is to dig a pit or not to dig.
Shovel. In those places where careful digging finds are not required (a forest, a arable field after harvesting, etc.), usually use a shovel.
Digging is more convenient than a big shovel, but often a small shovel, so-called "small sapper ", is more practical. In field conditions it can be used both as an axe, and as a cold weapon. Very high-quality shovels were produced in Russia before the First World War. Fastening of a cutting consisted of two parts and going at the end of the tightening ring. The sleeve for the cutting was quite long. Bayonet shovel calotypy of hardened steel.
Now conventional demining shovels for the army noticeably worse both in quality of manufacture, and on quality of metal. However, a number of Russian companies have mastered the production of good shovels, among which can be noted shovel production company "Spetsmaterialy " in St. Petersburg. It is made of armor steel and is capable of chop nails and a 15-mm corner. Convenient folding shovel is made in the Moscow Research Institute of Steel. There are 3 variants of shovel-from usual steel, armor steel and titanium. Occasionally in shops there is a spade "Special forces" and its civil variant "Mole ". The shovel is based on the idea of a drop-down knife. In the open position the latch pulls the halves of the handle and the rigid construction is obtained. On the basis of this shovel the so-called "small archaeological shovel " is developed. The shovel is small, metal, with overlays on a handle from a shock-resistant plastic.
Magnets. Recently on the market there were permanent magnets on the basis of compounds of rare earth metals. Their form is various-cylinders, plates, rings, rods. Such magnets, the size, for example, with Matchbox boxes, can raise weight. They can be successfully used in the search of iron objects not only at the bottom of reservoirs, wells, but also in the ground. So, the meteorites, having received a signal, did not bother themselves with the definition of the exact location of the meteorite, but simply loosen the ground under the coil and extract from it a meteorite with a magnet, fixed on a bayonet or a shovel shank.
Knee pads. Knee pads are used by miners, and skating enthusiasts. However, when working with detector, they are no less useful, although they look rather ridiculous. Fixed using Velcro. They are easily made of suitable materials-sponge rubber, felt, etc.
Bags for finds and debris. Made of fabric or plastic. Branded pouches have a kind of apron with two pockets-one for finds, another for garbage. Of course, you can put the finds in the pocket, and do not collect the trash, but the pocket quickly rubs, and the trash you will collect again, if you come to the same place in a few years.
Gloves. There are many objects in the earth that you can injure your hands, digging finds. These are glass fragments, sharp stones, nails, cans, etc. so it's better to work with gloves.
Device covers. When working in rainy weather, it is recommended to wear a special protective case on the electronic unit. Otherwise the water can get inside and the device is damaged. Such a case can be sewn also from the suitable fabric.
Bags for carrying the device. Metal detectors are usually delivered in cardboard boxes. In such boxes it is convenient to store, when the device is not used for a long time. However, at the departure to the nature more convenient to carry it in collected in special bags, similar to those in which the guns are transported.
Map-a tool for orientation on the terrain. The search works have to use a variety of cartographic materials.
There are hundreds of types of maps, but for orientation use basically two types. This is, first, maps where the existing territory is displayed as absolutely flat. The scheme lacks the nature of relief and depicts only objects such as highways and railroads, trails, rivers, lakes, towns and villages.
It is much more useful for search engines military-topographic maps (from which are removed vultures "secret "), giving an idea of the landscape and terrain of the shown territory, including the designation of the hills, lowlands, Gorges, rivers, lakes, cliffs, forests and swamps, as well as roads, paths, towns and villages.
Each map contains an indication of the scale used in its composition, which allows to judge the ratio between the length of the line on the map and the length of the corresponding line on the terrain. Usually the scale is specified both in numerical form as a fraction, and in linear.
The numerical scale, for example 1:50 000, shows that the real world is played on the map in one of its actual size. Thus, 1 cm on the map scale 1:50 000 represents 50 000 cm, i.e. 500 m on the terrain.
The linear scale has the form of a simple line divided into units of length, for example, kilometers. The distance between two points on the map can be measured using a compass-meter, which is then superimposed on a linear scale, reading the value of the real distance on the terrain in the familiar units of measurement of distances.
Unfortunately, maps are outdated, and in areas with a high population density it happens very quickly what was depicted (by the way, with very commendable accuracy), for example, on the maps of the middle of the XIX century, already outdated and modified: conducted new Roads, L EP, cut Forests, distributaries rivers and disappeared small lakes, outgrown suburbs, disappeared many villages, etc.
Therefore, along with the modern, very useful suitable for work places and old maps. These are plans survey the end of XVIII century, maps of Schubert and Mende (XIX century). You can get acquainted with them in archives, large state libraries, on the Internet. Old maps of some areas around Moscow can be purchased in the company "Rhodonite ".
The location on the map is described using the latitude and longitude elevations. On the Earth's Globe the lines of latitudes, called parallels, surround the globe as parallel to the equator rings, the diameter of which decreases as we approach the poles. Longitude lines, known as meridians, pass vertically through the poles, cross the equator at right angles and divide the Earth's surface into a series of segments.
Latitude. Imagine two lines coming from the center of the Earth, one of which is extended to you and the other to the nearest point of the equator. The angle formed by the lines is the latitude of your location.
Thus, the latitude is expressed in angular degrees by the measure of remoteness of the object to the north or south of the equator. The latitude of the equator is 0 °, and the latitude of the north and South geographical poles, respectively, 90 ° N and 90 ° LaChapelle latitude, for example, Moscow is 55 ° 45 ' N
Longitude is a measure of the distance of an object from the Zero meridian, which is an imaginary line connecting the north and south poles of the earth and passing through the Greenwich Observatory (Greenwich meridian) in London. The longitude of the object is expressed in degrees of the angle formed by two lines, one of which connects the center of the Earth with the place of intersection with the equator of the Zero meridian, and the other-the same center of the earth with the nearest point from the object on the equator. The maximum value of longitude 180 ° is fixed on the opposite side of the Earth from London.
When specifying the position of latitude and longitude latitude is always called and denoted the first latitude and longitude are measured in angular degrees. Latitude varies from 0 ° at the equator to 90 ° at the poles. Longitude can be from ° on the zero meridian to the maximum 180 ° east or west longitude.
In one degree-60 Minutes (60 '), and each minute consists of 60 seconds (60 ' '). One minute latitude is equivalent to one nautical mile (1.853 km). The distance between the neighboring elevations of minutes of longitude varies from zero at the poles to one nautical mile at the equator.
The exact location is specified in degrees, minutes and seconds (1 second equals approximately 30 m on the terrain).
GPS (Global Position System)-a modern system of global positioning and precise time on the basis of satellite fixation of coordinates. It is considered one of the most effective navigation systems and has recently been increasingly used in everyday life.
Portable GPS receiver, comparable in size and price with a mobile phone, will indicate your location anywhere in the world with an accuracy of 15 m and even less.
GPS-The brainchild of the American military Department. This system began to be developed in the early 1970s. As an accurate and reliable weather tool for the U.S. Army, Navy and Air Force. It was fully operational only in the mid-1990s. And soon found application in many other, quite peaceful areas of human activity.
The GPS navigation system consists of three separate elements: a control segment, a space segment, and a custom segment.
The management segment includes five ground stations stationed on U.S. Air Force bases around the world. These stations constantly monitor the operation of the satellites, control their exact position, adjust the orbit, synchronize the atomic clock and transmit to the satellites data on the exact location and time.
The space segment includes 24 GPS satellites rotating around the earth at an altitude of about 20 200 km. Total orbits 6 and each has 4 satellites. Each satellite in 12 hours makes one round of the Earth and constantly transmits radio signals in which the data is encoded both on its own position and speed, and on position and speed of all other satellites. In addition, each satellite transmits accurate time signals on its own atomic clock.
The user segment is represented by all GPS receivers available in the world, the role of which is to receive signals from the satellite and their decryption, so you can determine your exact location (with an error of up to 15 m) even in the conditions Zero visibility, specify the direction of the purpose of your journey and the distance to it. In addition, the receiver remembers your current position, so you can then restore this position, that is to return to the former place.
When the GPS system became available to civilians for the first time, the U.S. Department of Defense provided a military advantage in its use by incorporation of intentional errors into civilian GPS signals. As a result, if the military could determine its location with an accuracy of 15 m, and in some cases up to 1 m or less, the accuracy for civilians was about 100 m. On the orders of B. Clinton on May 1, 2000, the practice of entering errors into the definition Locations for civilians have been abolished and now the accuracy of the testimony of civilian and military receivers is quite comparable.
Today the GPS market offers many different receivers. Simpler models provide navigation information as a set of coordinates, which are then transferred to a paper map. More expensive models store in their memory one or more electronic cards, which are displayed on the display screen with an exact indication of your location.
An increasing number of GPS receivers are equipped with the ability to connect to a personal or laptop computer, which can be used to download electronic cards from laser discs or from the Internet, and then a high-resolution color display Provides the user with the same advantages that distinguish expensive models of GPS with built-in electronic card. Among such advantages-the indication of your location directly on the map, and not only the coordinates, which then need to be transferred to a paper card.
Sometimes, when you find that there is something in the ground, you can not locate this object, because it is too small. Of course, in the end you will get it, but it takes time. There are devices, so-called pinpojntery, which allow you to find such items in a few seconds.
Pinpojnter is a small metal detector whose search coil is installed at the end of a plastic rod. The device emits a beep when the desired item is at the end of the rod. Thus, when the normal detector you received a signal and while the Earth, can not find an object in it, pierce the ground with a bar pinpojntera and, receiving a signal, grab the ground at the end of the rod. The desired item will be in your hand. Pinpojnter is especially useful when searching for small items in sand, needles and other loose materials.