If you have some questions about metal detectors, the following FAQs may help you. And you also can contact us anytime when you meet with other problems in using them.
Q: How do metal detectors work?
A: When the search pattern of the metal detector touches metal, it interrupts the transmitted signal and this interruption or disturbance of the search pattern will cause the metal detector to alert the detector user (you) with an audio signal, usually a distinct loud sound or other indicating ways. In some cases flashing or blinking lights will accompany the audio signal. And LCD display detectors can let you distinguish the type of metal objects being detected.
Q: How deep can a metal detector go?
A: This question is the most frequently asked. However, unfortunately, there is no absolute answers. The following variables, in addition to your own detector's capabilities, all have an effect on the answer.
1. Conductive properties of the soil: Heavily mineralized soil usually reduce the penetration power of your detector. Soil mineralization may change greatly, and you may have to re-ground balance your detector to adjust for soil mineralization; unless, of course, your detector has automatic ground balancing.
2. The length of time an object is buried: Various chemicals in the soil have a corrosive action on metal. Some metals erode faster than others. For example, a modern zinc penny is attacked by these soil chemicals quite easily. However, the action on copper and silver is much less, and corrosive action on gold is hardly noticeable, if at all. As these chemicals damage the metal, rust takes place, which is absorbed into the surrounding soil. This causes the soil to become more conductive, which in turn makes the metallic object appear larger than it actually is and easier to detect. This is known as the "halo effect."
3. The size of an object: The larger the metal object, the easier and deeper it can be found. For example, a pail can be detected much easier than a little coin. The more surface area seen from above, the deeper the metal object will be detected.
4. The shape of an object: Every metal object reradiates at least part of the signal transmitted by your metal detector. In this way, objects function like additional antennas, and consequently their shape becomes important. Ring or loop-shaped objects lying flat, on or under the ground, produce the best results; flat or dish-shaped objects are similarly easy to detect. Rod-shaped items, especially when scanned end-on, are very difficult to detect unless they're made of iron.
5. The degree of magnetization: With ferromagnetic detectors, the degree of magnetization has a strong influence on depth. A magnet, for example, can be detected at much greater depth than an equivalent mass of iron. The more magnetization an object has, the deeper it can be searched.