  In a large range of physics and space experiments, the direction of the
magnetic field needs to be determined with an accuracy on the level of one
milli radian or better. We have proposed a new type of magnetic compass - a
rotation-based one, which provides an alternating signal from the Hall probe
proportional to the value of the magnetic field transverse to the axis of
rotation. The spinning Hall probe device has been realized. Alignment of the
spinning axis for a minimum (zero) value of the signal allows us to find the
direction of the magnetic field. The device does not require calibration and is
free of any drift problems. The measurement of the rotation axis direction was
accomplished by means of a laser and a flat mirror attached to the rotor. The
constructed prototype achieved an accuracy for the magnetic field direction in
the experiment with the polarized He-3 target on the level of one milli radian.
