What should be done if there is an air bubble in an orienteering compass?

Posted by admin 04/12/2016 2 Comment(s)

What should be done if there is an air bubble in an orienteering compass?

In the majority of modern orienteering sports compasses like FRENSON, Silva, Suunto liquid is used to reduce needle oscillations. When the ambient temperature decreases, the volume of liquid is reduced considerably more than the material of the compass capsule. This can lead to the formation of an air bubble in the compass. If a small bubble forms in the liquid-filled capsule, it has no influence on the accuracy of the compass.

Most liquid orienteering sports compasses have guaranteed functioning at temperatures above zero (0 to + 50 degrees Celsius). FRENSON compassses have been developed also for use in extra cold conditions, and tests show, that FRENSON compasses continue to properly function at temperatures even below -10 degrees Celsius.

As a compass is placed in warm conditions, bubbles tend to disappear, and in future they might not appear even in cold weather, as plastic material after such "workout" becomes more elastic.

The use of a compass at the height of 500 meters above the sea level may also lead to the formation of air bubbles.

If a small bubble forms in the liquid-filled capsule, it has no influence on the accuracy of the compass. Its appearance and disappearance are due to changes in temperature and atmospheric pressure. If a bubble larger than 1/4 inches in diameter appears, it is probably the result of a leaking capsule, usually caused by some form of shock damage, and the capsule will have to be replaced.

If a bubble appears during the warranty period* and does not disappear at room temperature in the plain landscape, FRENSON, Silva compasses can be replaced under warranty.

* Warranty period for FRENSON compasses is 3 years.

Tags: frenson silva

2 Comment(s)

Jeffrey Hobbs:

29/07/2019, 11:02:37 AM

I attended a winter hill walking course at a well known mountaineering centre in Scotland. The instructors, all highly qualified, insisted that you should get rid of any compass which develops a bubble. I have always found that bubbles do not affect the compass accuracy, but I am reluctant to disagree with the experts. I am still not sure if I should trust a compass with a bubble.

Ricky Moore II:

18/01/2020, 11:51:49 PM

I'm literally having to get rid of an old military compass because it won't hold a position due to the bubble affecting the wheel.

Cam:

30/10/2019, 09:02:44 PM

I have to agree with Jefferey, the surface tension of a bubble in your compass can (not will) affect the needle. Can is enough to buy a new compass! However, after recently buying a new compass because mine had a bubble, my bubbled compass has been sitting in a nice warm room all day and the bubble has miraculously vanished!!! I now have it in the freezer to see if it reappears.