Stray Induced Current

[dLj]

Some DC ampmeters do show you the direction of current flow.

I have always wondered if you could use a DC ampmeter to detect if

Induced DC Current Corrosion

was coming from a nearby boat.

Jim....

No is the short answer. The device is not sensitive enough. The geometry of the detector is not optimized for that kind of detection.

dj

 

[walt]

Just to get nit picky.. LOL..

Since that clamp on meter looks like it only measures AC current, it may use a generally less expensive "current transformer" principle. The link below shows diagrams for hall effect and current transformer clamp on current meters.

https://www.kew-ltd.co.jp/en/support/mame/detail.php?id=60

Someone mentioned that these measure magnetic field inside the loop (which is proportional to the current in the wire) and it was interesting that the meter picked up a stray magnetic field that was outside the loop but in close proximity.

Not really important at all.. but I wonder if you started to slightly open the jaws of the clamp, the stray magnetic field reading would increase? A gap in a coil (like you must have for the clamp to work) can have benifits but it also can increase flux in the air (flux infringing). So.. I also wonder if the meter clamps had any gap at all between the clamps? And if you pressed the clamps tightly together, would the parasitic reading (with no wire inside the clamp) reduce?

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