Comparison Garrett ACE 300i vs Garrett ACE 350

The design of the coil(s) of the metal detector.

— Concentric. The name of this type is due to the fact that such a coil includes two separate windings — receiving and transmitting — one of which is located inside the other. It is used in metal detectors that use the principles of VLF and VLFEX (see above). The field from a concentric coil has a small width, which determined both its advantages and disadvantages: on the one hand, due to this, it is possible to determine the location of an individual find with high accuracy, on the other hand, it takes a lot of time and effort to carefully examine vast areas. This shortcoming can be partly compensated for by the elliptical shape (see below). Also note that concentric models are quite sensitive to mineralized soils.

— Mono. The simplest type of coil, having only one winding. This option is used in PI, OR and RF devices, and in the latter case, two mono-coils must be installed. The main advantages and disadvantages of this type are similar to those described above concentric.

— D.D. Also known as Double-D. Such coils have a pair of windings in the form of the letters D, turned in different directions and arranged closely so that they form a circle or an ellipse. In terms of application, DDs are similar to the concentric coils described above, but they differ in the shape of the generated field: it is a narrow plane directed along th...e line of contact of the windings. This makes it possible to cover a fairly wide band in one pass, and also reduces the sensitivity to interference from mineralized soils. Among the shortcomings, compared with concentric ones, it is worth noting the high cost and lower accuracy in the localization of individual finds (however, the latter can be compensated by the skills and experience of the operator).

— Super-D. Coils of a specific design, consisting of three windings — a central one, which plays the role of a transmitter, and two external ones, working for reception. They were developed specifically for ZVT metal detectors (see "The principle of operation"), taking into account the features of their work.

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.

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.

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.

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).

Regular metal detector search programs include detection of coins, all metals, jewelry and relics. In some models, this list can be expanded with "Beach" programs, custom (user) detection mode, etc.

— Pin-Point mode(target designation). Possibility of operating the device in the so-called static mode, when the detection accuracy increases significantly (due to a decrease in range and discrimination ability). Note that this function is not found in pinpointers (see “Type”), despite the similarity of names - such devices are very accurate and without special modes. And among classic mine detectors, the Pin-Point mode is used only in models operating on the VLF or VFLEX principle (see above) - for other operating principles this function is, for one reason or another, irrelevant. Be that as it may, this feature can be very useful in accurately searching for small objects. The fact is that a classic VLF/VFLEX metal detector is able to “see” objects only if the coil moves above the ground - this simplifies discrimination, but noticeably reduces accuracy. In static mode, the device operates even in a stationary position, and the coil can be moved very slowly, which significantly increases the search accuracy.

— Setting sensitivity. Ability to change the sensitivity of the metal detector. High sensitivity makes it possible to search at great depths, but at the same time reduces resistance to interference, increases the likelihood of false positives and does not allow you to accurately determine the location of individual finds in places where signals are densely located (the device reacts to a group...of objects as a whole and cannot identify separate). Yes, and ground balancing (see above) is also connected. and with sensitivity. Therefore, this parameter is very important for setting up the metal detector for a specific situation.

— Threshold tone. The threshold tone is a low, monochromatic hum that the metal detector’s speaker or headphones emit in “neutral” mode, when there are no alarms. This feature has several uses. So, the tone can serve as an indicator that the device is turned on and working normally; This is especially true for models not equipped with displays. The pitch of the sound may change when the characteristics of the surface under the coil change - for example, when moving to soil with a different level of mineralization, or when detecting objects that “do not reach” the response threshold due to their small size or deep location; experienced users know how to use these tone changes for work purposes.

— Detuning from electrical interference. The presence of this function in the metal detector allows you to neutralize the influence of electromagnetic interference and prevent both “blurring” of the signal and false alarms. Such interference can occur for various reasons: from the proximity of power lines, radio transmitters or locators, when working near vehicles with running engines or near other metal detectors, etc.

— Tone identification. This function assumes that the metal detector, when triggered, emits signals of different heights - depending on the expected material and size of the find, its depth, etc. This feature is especially important for models that do not have a display. Tone identification requires some getting used to, but usually even inexperienced users do not have problems with it.

— VDI / Target ID identification. Metal detector function that helps to more accurately determine the type of metal. It is based on the display on the display of a numerical value inherent in a certain class of metal. Thanks to the table, you can significantly narrow the range of possible detected objects.

— Determination of target depth. A device function that helps determine the depth of the desired target. It is based on displaying on the display the numerical value of certain units of length measurement or highlighting segments of the depth scale.

— Vibration response. The presence of a vibration response system in the design of the metal detector. This system allows the device to send a signal by vibration of the case (similar to how this happens, for example, in mobile phones). In some cases, such a signal may be more convenient and appropriate than sound or visual indication. For example, when using a ground metal detector, the vibration of the device in your hand will almost unmistakably indicate that it has triggered, while the sound may be “lost” in the surrounding noise, and the visual indicator may be out of sight at the right moment. And in an inspection pinpointer (see “Type”), the vibration response can also be useful as a “silent warning” - so that the signal is not audible to the subject being inspected and at the same time reliably warns the operator.

— Volume adjustment. The presence in the design of a regulator that allows you to change the volume of the sound signal from speakers or headphones. Such a regulator can be located on the control unit, on the handle, on the headphones, etc.; however, in all cases its operating principle and purpose are the same.

— Low battery indicator. The metal detector has an alarm system that warns of low battery levels. This function informs you in advance about the need to take care of a fresh power source and prevents situations where the battery unexpectedly “dies” at the most inopportune moment. Note that the specific implementation of the indicator may vary: the signal can be visual or audio, and in some models, data on the battery status is displayed only upon the user’s command.

Additional accessories and parts included with the metal detector. These can be devices for protection and ease of carrying in the working position or during transportation — belts, bags, cases, rain covers for the control unit; special equipment required for work — for example, a grounding rod for models with the RF operating principle; and other additional equipment. The presence of batteries and a charger for them in this paragraph is indicated only if the device uses replaceable elements (see "Power"), because cordless metal detectors are by default equipped with a battery and “charging”, and there is no need to specify this. Also, this paragraph does not cover spare replacement coils — their presence or absence characterizes the “Number of coils” paragraph.

The length of a metal detector rod is usually indicated by the distance from the coil to the upper end of the rod (where the armrest is located, if any). The higher the height of the operator, the longer the boom must be so that he can hold the coil above the ground without bending over (or not bending too much). In most models, the length lies in the range from 120 to 145 cm — for most adults this is quite a suitable value. Note that the rods can be adjustable (telescopic) — to adjust for growth.