A compass orients you on your map, helping navigate your way through the wilderness and along trails. The compass can only be trusted if it has been taken care of properly. There are two types of compass -- floating needle and digital. If there is an air bubble on the interior of a floating compass, a crack in the exterior or a glitch in the screen, the compass might not accurately show directions.
Inspect the compass, noting anything that looks out of the ordinary or irregular. Compasses should not have cracks in the plastic. Whether in the sighting mirror, the adjustable bezel, on the base plate or along the needle, the materials should be intact. There should be no cracks, scratches or bends. If there is an air bubble inside where the needle is, the compass will not be accurate. The bubble will affect the way the needle turns and could give an incorrect reading. For digital compasses, if the display is not easy to read or seems scrambled, there is a malfunction.
Wipe the compass with a damp washcloth, removing dirt or other debris. Letting excess dirt and debris build up on your compass can cause malfunctions. For example, it might become difficult to turn the bezel if dirt is clogged between the piece that rotates and the base plate. If you own a digital compass, keep dirt out of the buttons and off the screen.
Remove the batteries from digital compasses, while not in use. The acid can leak and cause the entire piece to malfunction. You may not be able to salvage the compass, requiring you to replace the device. Always take extra batteries with you when hiking with a digital compass.
Store your compass in a small stuff sack or bag when not in use, both at home and on the trail. This will prevent dust from settling on the device if it sits on a shelf at home. The compass should not be unnecessarily exposed to the elements while hiking. Digital compasses will be water resistant, but might not survive full water immersion. A floating needle compass will not have any electrical components, but keeping the compass in a separate bag will prevent excess jostling and accidental falls.
Consult an outdoor retailer, if you need help reading your compass or it is malfunctioning.