Shape
The shape of the coil (frame) of the metal detector.
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Round. The traditional form used in almost all types of ground and underwater metal detectors (see "Type"); the only exceptions are models that work according to the RF method (see "Operating principle"). When using concentric coils (see "Coil Type"), this option allows you to create a conical field, which is convenient for pinpointing the location of the find, but reduces the covered area and makes it difficult to search over a large area; models with DD coils do not have this drawback.
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Elliptical. The shape in the form of a longitudinally elongated ellipse allows you to somewhat "stretch" the field created by the metal detector in length. This is especially true for coils of the concentric type — however, such an expansion somewhat reduces the positioning accuracy of individual finds. But in coils of the DD type, where the accuracy is by definition low, the choice between round and elliptical shape is most often not fundamental.
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Rectangular. A specific form used in RF or PI instruments. For technical reasons, it is considered optimal for such devices, but it is practically not found in other types of metal detectors.
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Butterfly. Another option used in DD coils along with the ellipse (see above). In fact, it consists of two elliptical windings
..., partially combined and resembling butterfly wings in shape — hence the name. This option is typical mainly for large-sized DD coils; with a large width, it is considered more optimal than an ellipse.Dimensions (WxD)
The size of the standard coil (frame) of the metal detector. Theoretically, the larger it is, the deeper the device is able to “see” and the more space it captures in one pass, but the worse it is suitable for searching for small objects and the lower the accuracy with which it localizes them. At the same time, these characteristics depend on so many other factors that in fact, the size of the coil itself affects them very little.
Note that for coils (frames) of an elliptical shape, only one size can be indicated — along the length.
Number of detection frequencies
The number of individual operating frequencies at which the metal detector can operate. For more on the frequencies themselves, see "Detection Frequency" below; here we note that the more options (
3 frequencies and more) are provided in the design, the wider the capabilities of the metal detector, the easier it is to adjust it to the specifics of the objects being searched and the environment. However, most models have
one frequency.
Detection frequency
The operating frequency (or frequency range) of the metal detector. This is one of the most important parameters when choosing a device, because the optimal frequency for different cases will be different — depending on the size and material of the items being searched, the characteristics of the soil and other factors. Detailed recommendations on the choice of frequency for each specific situation can be found in special sources; And already on the basis of this information, it is worth choosing a specific model.
Note that the actual frequency at which the metal detector will operate also depends on the installed coil — they are usually made for a specific frequency. Therefore, to use the full capabilities of the device with the ability to adjust this parameter, you may need replaceable coils.
Max. detection depth
The greatest depth at which a metal detector is guaranteed to be able to detect a metal object. Note that this parameter is most often quite approximate, moreover, somewhat conditional. This is due to the fact that it is usually indicated for an perfect environment (low-mineralized soil, a fairly large object, the material of which optimally matches the frequency of detection of the coil, etc.), and even for such conditions it is difficult to derive an absolutely accurate value. Therefore, in fact, the detection depth is highly dependent on a number of additional factors (from soil characteristics to user skills) and can be significantly less than indicated in the characteristics. Nevertheless, the claimed depth describes the capabilities of the metal detector quite well, and it is quite possible to compare different models with each other.
Note that a large depth not only increases the cost of the device, but can also adversely affect its ability to detect small objects.
Coin detection depth
The deepest depth at which a metal detector is capable of detecting small coins and other objects of similar size. Many users buy a device with the intention of “hunting” for metal trifles, so manufacturers often indicate this parameter separately in the specifications. Due to the small size of the coins, their detection depth is usually much less than the total maximum detection depth (see above).
Discrimination segments
The number of individual discrimination programs provided in the design of the metal detector. In this case, discrimination means filtering the detected objects using a discriminator (see above) so that the device does not work on unwanted objects such as pieces of foil, bottle caps, etc. You can also configure such a filter completely manually, but this may require special knowledge and create difficulties for inexperienced users. To avoid this, some models may have preset programs instead of manual settings. Thanks to such programs, the user just needs to select from the list what type of objects the metal detector should react to, and all the necessary settings will be set by the device's electronics.
More features
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LCD display. The presence of its own display in the design of metal detectors. This feature makes working with the device more convenient and visual: through the display, you can display more different information than with the help of an audible alarm or indicator lights, and it is easier to perceive. On the other hand, such devices are more expensive than similar models without a screen.
— Arrow indicator. The presence in the design of the metal detector of an analogue dial indicator to display data on the search process. Such an implementation is much more modest and cheaper than the same LCD display, but an order of magnitude more convenient than without visual notification at all.
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Display backlight. The presence of a backlight allows you to use the display of the metal detector in low light conditions — up to complete darkness. Note that this function can be useful not only at dusk, but also in the daytime — for example, when searching in a dense forest in cloudy weather. See above for details on the display.
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Built-in speaker. The presence in the design of the metal detector of its own speaker. Such a speaker allows you to use the device without headphones, which are not always convenient, and sometimes unsafe (for example, when working in places where traffic can move).
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GPS module. The pre
...sence of a GPS satellite navigation module in the design of the metal detector. This module allows you to determine the current geographic coordinates of the device, and the options for using this data can be different: recording search routes, fixing the places of individual finds, and even full-fledged navigation with laying routes from point to point.
— Armrest. The presence in the design of the metal detector of an additional support in the area of the operator's elbow. This support reduces the load on the hand, and also makes the hold more stable and at the same time controllable, allowing you to comfortably hold the device in one hand.
— Headphone output. The presence of a headphone output in the design of the metal detector. This can be either a standard connector that allows you to connect any compatible "ears" (for example, a 3.5 mm mini-jack output, popular in portable audio equipment), or an original proprietary interface that allows you to use only specialized "native" accessories. Anyway, headphones are often more convenient than a speaker, as they allow you to hear the signals from the device well even in a rather noisy environment.
— Headphones. The presence of headphones in the scope of delivery of the metal detector. Usually, such headphones have high quality and accuracy of sound transmission, so that the user can be guaranteed to hear all the signals and tone shades of the signals. "Ears" can be wired and wireless, and in underwater models (see "Type"), they are, respectively, made waterproof. This function is convenient because you do not have to search and purchase the best headphones for the metal detector on your own.Max. operating hours
The longest possible time of continuous operation of the metal detector without changing or recharging the batteries. Usually, some “perfect” time is indicated for the most optimal mode: constant stable operation of the coil without unnecessary energy consumption for sound signals, display indications and other additional functions, fully charged batteries or high-quality replaceable batteries, etc. Therefore, the actual time of continuous operation is likely to be somewhat less (how much depends on the features of the work). Nevertheless, this parameter describes well the battery life of the metal detector and allows you to evaluate its suitability for work "in isolation from civilization" (as well as the estimated number of spare batteries that may be needed for a complete survey of the desired territory).