Is it possible: Recalibrating Compass Needle

[enduro]

G'day all,

After a large rock fell on me and smashed my last compass, I purchased a nice and expensive Silva Compass from the UK and it arrived today.

Opening the packaging the first thing I noticed was that the needle wasn't turning north and quickly saw that is was because the needle was trying to point about 45' up into the sky.

The plan is underway to do the refund process but just in case this fails is there a method or realigning the needle?

[Strider]

Unfortunately the problem is that you have bought a compass designed for use in the northern hemisphere. Return for a refund if you can and either purchase locally or buy a compass with a global needle.

More on this here:
viewtopic.php?t=8791

[GPSGuided]

Expensive purchase. Try to return it and a refund, or sell it to a northerner. Useless here in the Southern Hemisphere.

[Zone-5]

Zone 5: Australia, Antarctica, New Zealand

Nope, declination is set by manufacture! Just make sure that you ask for Zone-5 as this is the declination zone for Australia!

Huge threads on declination here...

viewtopic.php?f=5&t=11773
http://www.rescuedynamics.ca/articles/MagDecFAQ.htm



Our zone (Zone 5) is generally shown on the base of a compass as the code MS (Magnetic South).

[Orion]

To correct it you'd have to rebalance the compass needle. That's not a practical DIY project, at least not for most people. If you're stuck with the compass and for some reason can't afford to buy another one, you could always just hold the compass at an angle every time you use it. I have an Australian compass and it works okay here at latitude 37N, as long as I tilt it a bit.

What I'd like to know is how to get rid of the annoying bubble in my compass.

[Mark F]

If you are unable to return it, you could try reversing the polarity of the needle which would? reverse the effect of the weighting. To do this place the compass between the legs of a strong horseshoe magnet for a couple of weeks. This would mean getting used to treating the previous S end of the needle as the N end.

[Turfa]

You can reverse the polarity of a compass needle pretty much instantly with a strong magnet. I got out my Silva compass last weekend & found that the needle was pointing South.... no idea how it happened, it wasn't stored near any metal or magnetic fields. I used a strong chart magnet and held it at one end of the needle & then pulled it along the top of the compass to the other end. The needle reversed itself instantly...I was quite surprised it happened that quickly. I then had fun flipping the needle polarity back & forth...... (might buy a new compass anyway..)

[madmacca]

In the southern hemisphere, the direction to the north pole is straight down through the earth. Whereas in the UK, it is close to straight along the surface of the earth (OK, exaggerating slightly, but you get the idea). Manufacturers balance the needles differently for compasses sold in the northern and southern hemispheres, so that they will swing freely where they are likely to be used, but if taken outside that zone, the balancing of the needle will be wrong. There are compasses that will work worldwide, but they are more complex.

Holding the compass at an angle might allow it to still swing freely, but it might not be as easy to use.