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Subject: Re: Compasses
From: Peter Fogg (ffive@XXX.XXX)
Date: Wed May 29 2002 - 18:18:42 EDT
Martin Gardner wrote:
> Are fluxgates subject to the same deviation error sources as real magnets?
Don't know anything about fluxgates, but the known azimuth of any celestial
body will give you a check on compass accuracy. Bodies on or near the horizon
are easy to read.
Am presuming that magnetic variation is not an issue. A compass adjuster earns
his living by coming on board and attaching tiny magnets around your binnacle
to counter any deviation and give it, as far as possible, a neutral deviation.
Sailing boats often have their motors under the cockpit, which doesn't help.
Another culprit can be the sheath knive kept strapped to the binnacle.
Compasses are not created equal - go into a store that has a few for sale and
observe how they fail to agree with each other. A final tip I aquired recently
- store your handheld upside down to minimize wear of the turning bearing.
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