Any detector has certain controls - knobs, buttons, switches, etc. Simple devices with only one handle. More complex can be up to a dozen different knobs and buttons. Briefly described below the purpose of these controls.
Fig. 21. The Cortes metal detector company Tesoro
Handle threshold settings
This pen is governed by one of the most important functions of the metal detector - audio threshold or optimal level of the sound signal required for to achieve the greatest sensitivity when the detector mode search for all metals with the ground balance. Process threshold settings in detail described in the attached devices to the instructions, but in any case the threshold the audio signal should be minimal, but visible to your hearing.
Most modern dynamic detectors the setting is automatically, and when operating in discrimination mode some models search goes without background threshold (the so-called silent search), which creates in the work of some comfort. Other devices require adjusting the threshold and in mode discrimination. Some appliances have a switch, and you can choose automatic or manual adjustment of the threshold that is needed when working on soils with rapidly changing salinity, characteristic, for example, to search nuggets of gold.
Handle ground balance
This pen is used to reduce the masking effect of iron-containing minerals on metal objects in the search mode, all metal mode and discrimination. If the setting is wrong the signal from deep for smaller objects will be inaudible in the background signal from the minerals of the soil.
Some metal detectors are permanently installed at the factory, the detuning from soil with average content of minerals. Such devices have no handles ground balance. More expensive models of the devices have automatic the detuning from the pound, which provides continuous monitoring of minerals the pound and is continuously being rebuilt from them, gives optimum depth of search that especially useful when working in areas with frequently changing salinity.
Handle discrimination
Discrimination is the ability of a metal detector does not give sound signal undesirable objects - nails, cork, foil, pull tabs from beer cans etc. If the discrimination level is set too high, then you are not hear the signal from the desired objects.
Some devices have two handles discrimination and a switch that allows you to the search to include additional discrimination. The same effect is achieved in devices with a single handle, when you are scanning the first object at the same level discrimination, and then, turning the knob, check it with another, higher the level of discrimination. Thus the instrument with two handles and diverter just save time in the search process and allow you to work faster.
Handle electoral discrimination
Unlike conventional discrimination, where when you turn the knob is offset all electrically conductive objects, with selective discrimination you can rebuild only to a particular object or group of objects, and zone discrimination can be narrowed or to expand and move along the scale of discrimination. Moreover, by using switch these objects or to ignore, or, conversely, to take. In the latter case, all objects that do not fall into this zone will be ignored.
In devices with microprocessor electoral area of discrimination can be observed on the display screen and adjust it according to your desire. You can install several such zones, and objects that fall within these zones, can be ignored or be taken with great accuracy. For example, you can configure the detector so that it will find only silver coins.
It should be noted that discrimination under any possible errors caused changing ground mineralization, the depth of the object, the degree of oxidation, i.e., the change in the electrical conductivity of the object compared to the benchmark. However, in General, both VCD discrimination speed up searches, especially of smaller objects coins and jewelry.
Knob sensitivity
This knob controls the gain of the secondary signal. In addition, it can to reduce the effects of electrical noise emanating from high-voltage lines and transmitting stations. Unfortunately, the value of this adjustment is often not understood quite right. Many operators believe that the higher installed the sensitivity, the deeper they will find objects. In reality it is not so, especially on soils with high salinity, when it is possible find deep objects, just lowering the sensitivity. Expensive models metal detectors usually have two handles sensitivity - one for static mode search all metals, another for searching in dynamic mode discrimination.
Visual identification of the object
With the advent of dynamic type detectors has made possible the identification of the object, or rather, the identity of the metal from which is made the object. More early devices it was a dial gauge with a calibrated scale. In modern devices use displays with LCD screen and the definition of objects is performed based on the measurement conductive properties and phase shift. The big advantage of this display information about the object is that it is independent from discrimination. For example, you set the discrimination level at which ignored nails, caps, pull tabs. While you no longer hear the audio signal from these objects, which increases your ability to distinguish between weak signals from valuable objects that are close in conductivity with discriminated objects. At the same time on a dial or on the move the cursor on the display screen you can see what is under the coil an object that, for example, may be a thin gold ring or gold chain. Such an object should be checked for digging it. Still not invented the detector, which would give an image of the object, however, in the future, these devices will certainly appear.
Audible identification of an object
In parallel with the development of methods of visual identification methods evolved sound identification, allowing the sound signal emitted by the device when an object is detected, to identify it with any degree of probability. The most expensive modern devices can have multiple audio signals signal with variable frequency, two - and three-tone signal and the signal type phone call.
Signal with variable frequency at some skill allows you to identify the object, not digging it, since the frequency of the sound emitted by the device, in this the case depends on the conductivity of the object: when it increases and increases the frequency of the sound.
Two-tone audio identification is used in devices with polling discrimination. Objects located to the left of zone discrimination, give a low tone, to the right of the zone - a high tone. Objects within the area, give a two-tone signal.
In devices with a three-tone signal (low, medium, and high tone) identification of the object is performed on the basis of the nature of the signal, as the latter depends on the conductivity of the object. This is convenient because it does not you have to constantly be distracted by the screen.
Some metal detectors upon detection of a large object emit a signal similar on a phone call. If you search monettako the signal is very useful because saves time.
The depth dimension of the object
Metal detectors with visual identification is capable of measuring the depth of objects the size of a coin. Since the device can detect a coin at a depth of up to 30 cm, and the range is scaled to the same depth. Unfortunately, the results of the depth measurements are often mistaken for objects whose size than coins. So, lead pellet on the surface of the pound gives testimony coins at a depth of 15 cm or relatively large object at a depth of 60-80 cm can be identified as a coin at a depth of 20-25 cm With experience you will learn to determine the depth of objects quite accurately.
Volume control
Most detectors do not have volume control. Therefore, the use of headphones when working with such devices is undesirable because your ear is experiencing significant load upon detection of the objects. More convenient to operate with headphones that have a volume control. If the detector has a controller the volume of your headphones also feature a volume control, it is recommended to configure the detector for maximum volume and headphone volume be adjusted so that the signal from a large object would be acceptable for your hearing.
Check batteries
As a rule, check the condition of the battery occurs automatically the first the inclusion of the metal detector in the 3-5 sec. beep on the strength of which is judged on the condition of the batteries. Some detectors, with arrow indicators the battery condition is estimated on the status the arrows automatically when you first turn on the device or by pressing a button. Usually "rested" batteries have a high voltage. Therefore, a more exactly the status of the batteries can be judged only after 15 minutes of using the device.
The metal detectors with LCD display the battery status continuously displayed graphically in the form of a number of segments, the number of which decreases as the batteries are discharged, directly or in the form of voltage in volts. Some devices with a significant battery drain emit light or an audible signal indicating that the voltage dropped and the batteries will last only for one hour of work.
The switch operating frequency
This switch allows you to change the operating frequency of the metal detector to to reduce the impact of working a few metres from the devices. This is especially important if you participate in the competition in search, where often you are surrounded by a few people who have the same model of the device, what and you. It should be noted that a significant frequency deviation from the norm can to reduce the depth of operation of the detector.
Button pinpointing
Although the term "pinpointing and which are absent in the Russian language, however the use its in the description of the detectors is more appropriate than the phrase "detection the exact location of the object using electronics" that he, in fact, means.
When you press this button, the object gives a beep when it is exactly under the center of the coil. This is due to the short-term imbalance threshold, whereby the electromagnetic field becomes less sensitive to object.
Some of modern metal detectors in the mode of use pinpointing special sound generator, which modifies the frequency of the signal as it approaches the center of the coil to the object. Unfortunately, when it detects large object search its exact location is accompanied by unpleasant feeling, resembling the roar of sirens. The advantage of this device functions is clear the difference of a few objects that are located close enough to each other
Author: L. V. Bulgak