Pulsed IB-VLF Detector instead of PI-Detector.

[Anonymous]

What about a pulsed IB-VLF detector instead of PI-detector?
PI detectors usually dont process the phase information (phase shift) of the target. Just the eddy current and involved effects.
It has shown, that IB-VLF detectors beat the PI-Type one´s. We should marry IB-VLF and PI-Type together, to take the advantages of both techniques.
Has anyone designed such a detector? I am wondering, whether it is possible.
Aziz

 

[Anonymous]

Aziz,
Eric Foster made a true PI with a balanced searchcoil which could discriminate over twenty years ago. The problem is that the reactive component suffers from ground effect. Using filters such as a motion VLF will result in a major reduction of depth over a regular PI. In short it has been done and may well prove to be a method for the future once the problems involved with such designs are solved. The dream is to find a reliable method of making a regular PI discriminate like a VLF using only a mono coil.

 

[Anonymous]

Hi Dave, When you say "discriminate", do you mean determining if the target is ferrous or non-ferrous, or are you referring to distinguishing between different kinds of non-ferrous targets, such as zip-tabs and coins?
Allan

 

[Anonymous]

Allan,
I am talking about a fully variable discrimination control such as the control found on a VLF. Maybe even a notch discriminate control to boot! The detector Eric made was ferrous / non ferrous only but it goes to show you how far ahead he has been for so long. He made that detector over twenty years ago!!!