Conductvity refers to how well a target allows electrical current to flow through it. In other words a highly conductive target has low electrical resistance and therefore allows current to flow more easily. Conversely a target with a low conductivity has high electrical resistance and does not allow current to flow easily.
Discrimination is a metal detector's ability to identify buried targets based on conductive and / or ferrous properties. Based on measuring these properties, it is possible to determine valuable targets from junk targets so you can spend more time digging valuable targets.
An electromagnetic field is a magnetic field that has been generated electrically. Metal detectors radiate an electromagnetic field from the search coil. This influences buried targets, which then affects the signal recieved back by the detector.
Ferrous objects / targets contain iron and therefore are attracted to a magnet, for example; horse shoes, nails and tin cans. Many natural and man made objects contain iron, most of these are junk targets, however some can be valuable relics.
Non-Ferrous materials do not contain iron. Good Targets include coins, gold rings and copper atrefacts. Junks targets include bottle tops, pull tabs and aluminium foil.
The frequency of a metal detector refers to how fast it sends signals into the ground. Frequency is measured in Hertz (Hz). Certain frequencies detect certain targets better than others, e.g. high frequencies find very small targets while low frequencies find deeper / larger targets.
Ground mineralisation refers to how magnetic the ground is. This doesn’t mean that mineralised ground produces a magnetic field, but it does mean that particles or grains in the soil will be attracted to a magnet. Metal detectors see mineralised ground as one huge target, which makes detecting buried targets in mineralised ground difficult. Minelab invented true automatic ground balancing technology in 1987 to successfully counteract the effect of ground mineralisation.
Noise cancel is a metal detector feature that shifts a metal detector's operating frequency or frequencies to reduce the effect of environmental electromagnetic noise, from sources such as power lines, cell phone towers and other metal detectors.
Target refers to any metal object that can be detected by a metal detector. A target can either be valuable such as coin, or junk such as a bottle top.
Target ID numbers and audio tones are produced by a metal detector to enable you to identify targets based on their conductive and / or ferrous properties.
Threshold is the continuious sound used to listen for target signals. The Threshold will 'blank' to indicate the detection of a discriminated / rejected target.