دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: See magnetic declination。

n: an imaginary contour on the earths surface joining places where the magnetic declination is the same.

n: a map that shows the isogonic lines joining points of magnetic declination, which is the variation between magnetic north and true north. For example, in Los Angeles, California, when the compass needle is pointing toward north, true north actually lies 150 east of magnetic north. See declination.

n: th angle between true north and magnetic north,this varies with geographical location, and also changes slightly each year.