Metal Detector Discrimination
Inevitably, some metals are undetectable by a metal detector. On the contrary, you can also set a metal detector to detect only a particular type of metal. It is possible as most metal detectors have a discrimination feature.
Discrimination is the device’s ability to ignore certain metals buried underground. Instead, it will only alert the operator once it locates a target that it identifies based on ferrous properties and conductivity.
To simply put it, setting your metal detector discrimination is like telling your device to be quiet when it senses invaluable targets.
Moreover, the discrimination feature varies in metal detectors:
A dial sets variable discrimination. This dial increases and decreases how much discrimination your metal detector is set to respond to.
In addition, variable discrimination is helpful if you are used to operating a metal detector. The reason is that such people already know how much or how little discrimination they need to apply when finding targets.
This type of discrimination prompts the metal detector to identify a notch or notches in the uninterrupted conductivity range. This way, the metals within the notched-out area will either be included or excluded in the target finds.
Additionally, metal detectors feature proprietary discrimination settings. This feature allows the devices to improve their notched discrimination setting further. You can run the metal detector to notch reject or notch accept targets.
Notch reject prompts the metal detector to ignore every metal within the notch range. On the other hand, the notch accept mode lets the device receive everything in the notched range.
Moreover, it is essential to note that not all metal detectors have discrimination settings.
Pulse Induction (PI) metal detectors use a different technology when locating targets. For this reason, they usually do not feature a discrimination mode.
Metal detectors are good for finding silver, gold, and jewelry. So, the question of whether or not it can locate diamonds seems to make sense.
But as mentioned, metal detectors can only locate ferrous and non-ferrous metals. So, it will not detect diamonds as they do not have metallic properties. The same principle applies to gemstones and pearls.
However, you can detect a diamond embedded in a ring. This piece of jewelry usually consists of silver, gold, or other malleable metals that are electrically conductive.
Furthermore, your metal detector will not detect other items such as papers, bones, gemstones, stone figures, and pearls.
Can a Metal Detector Find Silver
Silver is one of the most common metals used for making jewelry. For this reason, it is understandable if metal detector users are trying to target silver jewelry when they are metal detecting. But will this metal set off a metal detector?
There are nine major types of silver. To see if they will set off a metal detector, let us look at the composition of each of them.
Silver jewelry all contain alloy metals. The most common metals added to them are copper and nickel. Moreover, these metals are good conductors of electricity. For this reason, silver is not one of the metals that a metal detector cannot detect.
In addition, silver is the best element to conduct electricity. So, if there is a silver piece of jewelry in the area where you are metal detecting, it will undoubtedly set off a metal detector. Even silver-plated metals can set off a metal detector.
Graphite is a naturally occurring element that comes in crystalline carbon, which you will commonly find in igneous and metamorphic rock. That said, graphite is a form of the mineral.
Additionally, this mineral is exceptionally soft, making it split even at a little bit of pressure. Graphite also has a very low specific gravity.
That said, graphite is non-metal. But despite this factor, it can still conduct electricity. For this reason, you might think that a metal detector can detect it since the device utilizes an electromagnetic field to find metals. But on the contrary, you may think that it is not a metal, and a metal detector cannot detect only a few metals.
However, graphite belongs to what is called hot rocks. For this reason, it will set off metal detectors despite being a non-metal element.
Hot Rocks refer to stones that have absorbed significant amounts of minerals such as zinc and iron.” He added that hot rocks can “cause false positive signals.”
Graphite is a form of hot rock. Hot rocks, such as pebbles and elements, contain low conductive minerals. These rocks can disrupt metal detector signals by sending alerts when valuable metals are buried in a specific area.
Moreover, there are two types of hot rocks – negative and positive.
Negative Hot Rocks
Negative hot rocks contain high Magnetite concentrations – an Iron Oxide that turns rock and sediments into black. The iron oxide molecule also has a high atomic weight, making rocks and sediment heavy.
Moreover, one of the most common types of negative hot rocks is black sand. It has a high amount of Magnetite, allowing it to set off a metal detector.
But while your metal detector can read this response, the sound the device will produce is less definite than the sound coming from real targets.
A delayed acquisition often accompanies the false-metallic audio response. There is also a nulling audio response when you move the search coil away from a negative hot rock.
Positive Hot Rocks
Positive hot rocks are good conductors of electricity. They contain high Maghemite concentrations – an iron oxide that causes rock and sediment to become red, reddish-orange, and even yellow.
In addition, positive hot rocks are good conductors of electricity. They consist of high concentrations of sulfide minerals, specifically Pyrrhotite and Bornite.
Moreover, graphite is a form of positive hot rock. So, if your metal detector is set to a low level of sensitivity, it will be able to detect signals from graphite. As a result, the graphite can interfere with your metal detector’s signal.
There is no denying that metal detectors are highly technological devices. For this reason, it can detect almost every type of metal that is buried under the ground. If you are lucky enough, you may even find valuable metals, such as gold, silver, and jewelry.
However, it is essential to note that there are metals that a metal detector cannot detect. The reason is that these metals have low electrical conductivity, so they cannot create an electromagnetic field for metal detectors to read.
In addition, metal detectors are not meant for finding non-metal elements, such as gold, gems, and pearls. But if these elements are on metal jewelry like rings and necklaces, you may detect a valuable find in the area where you are metal detecting.