Anyone have experience with globally balanced compasses? Here's a quote from the Suunto website about their version.

--------------------------------------------------------------------------------------------------
"Suunto also makes globally balanced compasses, which can be used accurately in either hemisphere."
--------------------------------------------------------------------------------------------------

Does this mean that declination angle does not need to be set and it's still accurate anywhere or is this something different? This globally balanced compass stuff is all new to me and I don't completely understand it. I know on my Suunto M-2 or my Timex Expedition watch/compass (the only two I own that allow for custom delination angle settings) I just look at the map to see my declination angle for my current location and the current year then I set the compass but (and this may be the problem) I really dont know what this exactly means and if it is even any different with a globally balanced compass. Do you still set declination angle on a globally balanced compasse?

Thanks

I believe its due to the fact that the needle gets jammed against the housing. Similar to the effect of tipping the compass, to an angle similar to the change in latitude you travel from where the compass was set.
I did'nt believe globally balanced compasses were possible <img src="/images/graemlins/confused.gif" alt="" /> This effect is different to declination, so setting it will still be necessary.

James

Oh I see what you mean and how that would have nothing to do with declination angle. Thanks Jimmy.

IIRC a few months ago, one of our Australian friends, posted a few messages about the angle of the needle depending on your latitude (the needle is not horizontal), thus preventing standard compasses to work everywhere.

I have one from Suunto. I bought it because of the price and a glow in the dark ring for the scale. It does not need to be set for different inclination (which require to change the capsule) and has an djustable declination.
I´m very satisfied with it. Tilting is much less of a problem than it was with regular compases. I think this is an advantage when you are tired or in rough terrain. I prefer it over a regular compas anytime even when I don´t plan to go to the southern hemisphere.

Here is a good discreption on the Global needle.
The compass store.

20

I'm more confused, 20 degree allowance?

I can only understand that the 20 degrees is the maximum variation between latitude and variation in the earths magnetic field, horizontal at the equator, perpendicular at the poles but not necessarly following the curvature of the earth?

Please can someone clarify this issue.

Suunto It appears the Suunto and Casio compass watch has a function for setting the magnetic variation but it's not automatic. So you would need to know your local variation setting. Pretty cool but nothing beats the potential for accuracy as a good old magnetic needle.

Magnetic variation, or declination is not only changing constantly, it varies many degrees from region to region. The National Geophysical Data Center has a web site where you can find the exact magnetic declination for different regions.
To Find Variation

A needle pointing towards north is "Magnetic North". In order to use your compass for accurate locating, you need "True North". The difference between true north and magnetic north is the magnetic variation, which may vary to 25 degrees.

When you buy a pocket compass, many have a rotating needle rings that will allow one to set in the magnetic declination and therefore refer to a true north meridian, or true north. These compasses will work on either north or southern hemisphere. The leveling of the needle may be interrupted by local magnetic attraction (lode bearing bedrock is one source) but your compass has to be pretty precise to be adversely effected.

BTW....in a pinch you can determine your local magnetic declination using a shadow stick. More on that later.....

Here's a good site that shows the magnetic declinations in North America and explains the compass setting. Variations in North America

Forget about latitude and the curvature of the earth, with a compass you are attempting to find a true meridian, or a longitudinal line, that is a true north-south line. The difference between the true meridian and magnetic north is the called the variation, deviation or declination (all the same thing). So, if you have a compass that has features that allow for this setting, you turn the needle ring the correct number of variation degrees. This way the compass needle is pointing at magnetic north and the compass north alignment is on a true north meridian.

Well, according to the explanations found at the URL indicated by KR20, that's exactly why globally balanced compasses are offered.... <img src="/images/graemlins/grin.gif" alt="" />

And that was BRIAN's original question.

And, yes, you are right, it has no relation with magnetic declination, which is a totally different subject.

The tilting has nothing to do with magnetic variation. When you hold the compass plate level a balanced needle (i. e. CG supported) tends to tilt in a plane that goes through the axis and the center line of the needle. That would cause the needle to drag on the plate and significantly reduce accuracy. You can make one end heavier to compensate this effect. The earth´s magnetic field lines do not meet the surface at the same angle for every latitude (the angle is called inclination). Hence a regular needle would not work for every lattitude.

I'm sorry Frenchy, I was answering Max's question.

oooopsss...
' didn't see it ....
sorry.