Question concerning the demagnetizing of Compasses.

[Juva]

Bought a Cammenga 3H. Works perfectly, when tested, only 5 mills off sun's azimuth.
I keep it in my shelf, worried the electromagnetism from perhaps the pipes in the walls or the electrical wiring may mess it up? I would preferably like to keep this compass for life and I do not want to ruin it in the first month of ownership because of my house's infrastructure being unfortunate.
How bad does the magnetism have to be to ruin such a compass? Even by just changing it by 10 mills/half a degree?

Thank you for your attention towards this matter.

 

[Pony Soldier]

I've spent my professional life with Brunton compasses. I have never seen a change in the compass magnetically. However they do get gummed up at times so be aware of hampered movement.

I have had both the free movement and the buffered movement for faster response. I guess I like the buffered version so I don't have to wait so long for an answer.

Not knowing where you are but there are magnetic fields in nature that can give you answers that are 180 degrees of real. Working in conjunction with a map can keep them honest. In mapping underground I have seen as much as 20 degree deflection between foresites and backsites.

I suggest using a compass in conjuction with other tools to compensate for local influences.