This may be a litte more technical than some want to bother with but I thought I would go a little deeper into this. There is the idea that the Explorer has problems with soil mineral which is not at all correct so I thought I would go ahead with this and take a chance of being run out of town.
Iron is often mentioned as having permeability but there is much more to the ID of iron with a metal detector. In discussion the magnetic properties of iron we need to understand permeability, reluctance, and retentivity. Iron can be classified in general as soft or hard. We then consider how easily a piece of iron can be magnetized which is the reluctance of the iron, how well it retains magnetism is retentively. Soft iron is easy to magnetize but easily looses the magnetism if the force that magnetizes it is removed. Hard iron is more difficult to magnetize but will hold that magnetism. A magnetic tape recorder head or relay armature is a good use for soft iron where we want a magnetic to be temporary. A permanent magnetic would be made of hard iron.
Len
Iron is often mentioned as having permeability but there is much more to the ID of iron with a metal detector. In discussion the magnetic properties of iron we need to understand permeability, reluctance, and retentivity. Iron can be classified in general as soft or hard. We then consider how easily a piece of iron can be magnetized which is the reluctance of the iron, how well it retains magnetism is retentively. Soft iron is easy to magnetize but easily looses the magnetism if the force that magnetizes it is removed. Hard iron is more difficult to magnetize but will hold that magnetism. A magnetic tape recorder head or relay armature is a good use for soft iron where we want a magnetic to be temporary. A permanent magnetic would be made of hard iron.
Len