compass deflection

English

Noun

compass deflection (plural compass deflections)

1. The difference, expressed in degrees, between the direction a magnetic compass needle points and true or astronomical north; magnetic declination.
2. Differences, expressed in degrees, between magnetic north directions and the direction a magnetic compass points, owing to local magnetic interferences; magnetic deviation.

References

• United States Bureau of Mines, Dictionary of Mining, Mineral, and Related Terms (1996).