Manual Ground Cancelling
One of the most vital characteristics to remember when picking out a multipurpose detector for prospecting of gold is to ensure that it is able to null out heavy iron mineralization that can be found in almost all gold bearing areas around the world. Not to misunderstand what has been said though, this does not mean that gold can only be found in magnetic black sands. What is true though is that usually people that do dredging in rivers and streams encounter black sand. Almost all of the terrain that bears gold has a little to a fair amount of mineralization. In actual fact, the worse problems occur in places where there are the infamous hot rocks which are hot areas of mineralization that we will get into later on. Some of the worse kinds of soils can be found in the West area of the United States including Northern Arizona and Northern California; however the one known to take the cake is in Western Australia. Terms such as magnetite, maghemite, and hematite are usually utilized to describe these types of soils but they are in actual fact mineralized soils. Keep in mind that one of the most important characteristics to look for in a metal detector is ground cancelling. There are certain detectors that do this manually by letting the operator handle a ground balancing knob and this works to neutralize the interference that ground mineralization produces. When the operator has turned the metal detector on and is ready to use it, he should be able to bare hear a little bit of a hum or threshold sound. When the metal detector is placed down close to the ground when ground canceling is being done, this threshold sound or hum should either completely disappear or get louder. The reason this occurs is due to the effect the ground has on the detector which is how one can tell if the metal detector is balanced so as to neutralize it. If the mineralization in the ground is heavier than what the detector is set for, it will usually cause the sound to fade away completely. The ground balancing knob will then need to be turned (in most cases clockwise) to set it to the appropriate level for heavy mineralization. When the detector is set for lighter mineralization it will cause the threshold sound to become louder; the ground balancing knob then needs to be moved (counter clockwise in most cases) in order to set it to the appropriate level for lighter mineralization. Lower the loop down to the ground and if there is very little change heard in the sound, it means the metal detector has been adjusted adequately for ground mineralization. Metal detector manufacturers have their own way of reaching ground balance however the formula previously described is the most common one utilized. Make sure when purchasing a metal detector to follow the instructions of the factory manual for exact ground canceling dealings and obviously, go for a detector that has the ability of ground canceling.