Interesting phenomena

[bugwhiskers]

If you place a coil near a PI metal detector the detector sees nothing...if you short the connections of the coil...the detector sees it.

Any metal be it cabling or connectors that form part of the conducting path to the coil don't seem to be seen as a "target".

[Qiaozhi]

If you place a coil near a PI metal detector the detector sees nothing...if you short the connections of the coil...the detector sees it.

Any metal be it cabling or connectors that form part of the conducting path to the coil don't seem to be seen as a "target".

When the coil is open-circuit the cross-section of the wire is small, so it does not present a large enough target to the detector. Connecting the ends of the wire together will effectively create a shorted turn, which allows eddy currents to flow in the loop. This is the same phenomena that causes iron rings to look like good conductive targets.

[Geo]

If you place a coil near a PI metal detector the detector sees nothing...if you short the connections of the coil...the detector sees it.

Any metal be it cabling or connectors that form part of the conducting path to the coil don't seem to be seen as a "target".

When the coil is near the coil of the PI then it works as a transformer with open secondary (nothing is happening). But when we short the second coil is the same as we short the secondary of a transformer. Primary will see it
(with a large current). So detector PI will see it , it is exactly the same.