When using any discrimination - The Detector only sees the difference.
One Comment
Filed under: Articles, Machines — Norfolk Wolf
As shown in the diagram the detector will have a base-line at the ground setting and if in all-metal, it will “see” the large difference between the ground and any metal.
Now introduce Discrimination, starting at Iron, look at the smaller amount of difference the detector sees between the Iron Disc setting and a Thin Coin. Increase the Discrimination to ignore “Coke” and check to see just how small the difference is between that and the thin coin.
Imagine you are watching cars go by as you look through window with the curtains open, colour make and model are easy to recognise. Every car is seen with a good clear view even though they are moving; this would represent the All-metal mode. Now as you add discrimination the curtains start to close, and as the view gets less and less it becomes increasingly difficult to see differentiate the colours let alone what make or model of car that is going by.
I used the analogy of cars as this will convey movement over the ground, just the same as your coil will be doing. Imagine how much less your detector has a chance to tell the difference when you start sweeping the coil too fast and this diagram is for clean less mineralised ground. On more mineralised ground, the gap between that and iron becomes less as the mineralisation becomes worse!
John Lynn
December 31st, 2007 at 6:50 pm
Very nicely put, John. Maybe your article could also be titled “Indiscriminate Use of Discrimination” (hah).
As you’ve said so well in other forums and articles, to be successful at metal detecting you have to understand basic electromagnetic concepts, know your detector, and use good detecting techniques. You can’t just pick one up, start waving it around like you see in the commercials, and expect to find goodies right off. Like everything else in life, to get good at it takes time and effort.