Thursday, July 22, 2010

Just a note of caution regarding compasses

Because of dip angle effects I bought a new compass in the UK rather than trying to use my NZ compass. Last night when pitching camp I wanted a clear line of sight to the morning sun to dry the tent. I took out my compass. According to my compass East was in the wrong place, just about where the sun was setting! Low cloud hid the exact location. MY COMPASS IS NOW MAGNETISED 180 DEGREES OUT OF ITS ORIGINAL ALIGNMENT! I remember things didn't seem right getting off Fan Gyhirych and I resorted to checking wih gps. Because of the remagnetisation the weight compensation, to balance the dip effect, is also now in the wrong direction. The compass now sticks! I kept my cell phone and compass in the same jacket pocket for a while and l think that is when the remagnetisation must have taken place.

I have now narrowed down the compass problem to the case I bought for the cell phone. It is held shut by a powerful magnet! Beware Paul as I think you have the same sort of cell phone case!

1 comment:

  1. This seems quite often to happen to my compasses, Richard. Curiously, first on a visit to NZ when I was foolish enough to take a northern hemisphere compass. Stroking with a magnet 're-sets' them.

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