Ferrous-Coin or High Trash

[Crusty]

Is it me or am I seeing a pattern here where people seem to be coming to the conclusion through real world hunting that High Trash target separation ID's rusty iron more accurately than Ferrous-Coin? Specificully that there is much less false target returns in the Co. 40 to 46 range.

Dave

 

[Digger]

Is it me or am I seeing a pattern here where people seem to be coming to the conclusion through real world hunting that High Trash target separation ID's rusty iron more accurately than Ferrous-Coin? Specificully that there is much less false target returns in the Co. 40 to 46 range.

I'd say audibly, but not likely visually. I had a lengthy discussion with MInelab regarding this matter, while doing the Field Tests. From what I now understand.............

As a target value becomes more conductive (either due to its material properties, size or orientation) it begins to respond more and more like ground. Therefore, a trade-off must be made between too much falsing and the aggressiveness at which highly conductive targets can be correctly identified. The Ferrous-Coin signal processing could have been made to correctly ID highly conductive targets but there would be excessive falsing if there was any ground mineralization (i.e. ground would respond like coins).
In the real world this would not be very helpful, so a more acceptable compromise was implemented in the CTX 3030. By making the Ferrous-Coin signal processing more robust against some (mildly) mineralized ground the correct target ID is limited up to a certain level of conductivity. The net result of the conductivity limit for highly conductive targets, like a silver dollar, is their ID is shifted to the 12 Fe (12.xx) line, which is where most targets with coin-like characteristics are displayed. A further side effect of this conductivity limit is that there is a difference between the real received signal and the conductivity limited signal produced by the Ferrous-Coin processing. The difference between the two is interpreted by the detectors processing as a 'ghost' ferrous signal, which typically appears in the bottom right of the screen, just like a ferrous target.
When using Ferrous-Coin, in the example above,

 

[JamesM]

Digger,
As usual, great explanation. Why don't you sticky some of these in the resource center or add them to the FAQ. Your explanations on topics such as ground balance, threshold ect. would make great info stickies.