N017RW said:
ianwood said:
4wd said:
Has anyone got definitive proof the compass is affected by launching from on or near metal objects?
I launched from a steel plate flat farm bale trailer several times without issue.
I'd say 1/3rd of all fly aways start with a take off near ferromagnetic materials. It's not a guaranteed fly away, but you're making it much more likely.
How so?
It's easy to see the effects/distortion caused by near-by objects with a compass. But once you move away or increase proximity the effects subside and even disappear.
Assuming no gaussing occured because of exposure, as would be the case for non-magnetized materials, why would a magnetometer act any differently?
Found this online... I am wondering if the concern is a semi-permanent disruption of the magnetic properties of the compass... but based on the below - it would have to be pretty strong to have a lingering effect. I would imagine that the biggest concern is determining "Home" - if you don't re-establish "home" after a magnetic field interferes with the compass - I could see a fly-away being the result of the Phantom not really "knowing" which direction "Home" is. I dunno - just spitballing
Why does the compass respond when it is near an electrical wire with current flowing through it?
We can conclude from this experiment that an electric current causes a magnetic field around it just like a magnet causes a magnetic field. When you moved the compass near a bar magnet, the needle pointed toward the magnet's magnetic field and not toward the north. When you put the compass near the electrical wire with current flowing through it, the compass did not point north; instead, the compass needle pointed in the direction of the current's magnetic field.
What would happen if we put a ferromagnetic object into the magnetic field?
Now we have established that a conductive wire with a current flowing through it has a magnetic field. If we put a ferromagnetic object in this magnetic field, the object will concentrate the strength of the field and cause the object to become magnetic. Once the current flow in the line stops, the magnetic field disappears and the object stops acting like a magnet. However, the magnetic field of one wire is small and does not have much strength, so it can only make temporary magnets from small objects. But, let’s say that we take a wire and coil it several times to form a long coiled piece of electrical wire, and then we turn on the current. We would have a magnetic field much bigger and stronger than we would without the coiled piece of wire, and we could magnetize even larger objects.
An iron bar placed through the center of the coiled wire would become a temporary magnet, called an electromagnet, as long as the electric current is flowing through the wire.