Long Distance Travel

Recalibration of the compass may be necessary if the vehicle is operated a long distance away from the point of the initial compass calibration. There are many reasons for this, including the following:
^ Differences in the magnetic declination
^ Changes in the angle formed between the magnetic needle and the geographical meridian across the country
^ The coordinate system used by the compass to determine direction (magnetic north)

When these circumstances arise, a malfunction may be suspected when, in fact, the system is operating normally.

An approximate 15 degree deviation (declination) from true NORTH occurs between the east and west coasts. This declination is the result of the earth's curvature. Various other deviations throughout the country are the result of differences in the magnetic fields.