| || What Is A Global Needle?
|I build Doug Ritter Aviator Survival Paks like my life depended upon it... |
|...because your life might.|
What is a Global Needle and why should you care? In order to understand the concept and advantages of a Global Needle, you must first understand a few basic principles of the modern compass. In order to get an accurate reading, the compass needle needs to be "balanced" in the capsule so that it does not drag on the top or bottom of the capsule. But, because the horizontal and vertical components of the earth's magnetic field vary considerably in different locations, a compass needle that "balances" perfect in North America will drag or stick in South America. As a result of these magnetic variances, the compass industry has divided the earth into 5 "zones", as identified in the map below. Virtually all conventional compasses putchased in the U.S. and Canada are balanced for zone 1.
However, Suunto has developed a patented Global Needle that will perform perfectly with needle tilts of up to 20 degrees. This allows a single compass to be used effectively in all 5 of the earth's compass zones (see below). So, a compass outfitted with a Global Needle provides true world-wide performance.
But, what if you're not a world traveler? Why would you want a global needle? Well, the global needle's unique ability to handle tilts up to 20 degrees makes it perfect for pathfinding without having to stop. Not having to level the compass exactly makes it easier to take an accurate reading while you're still moving.
A special thank you to Suunto for the use of the zone chart, above.
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First Published on: May 5, 2006