  We present a modified scheme for detection of the magneto-optical rotation
(MOR) effect, where a linearly polarized laser field is interacting with cold
$^{87}$Rb atoms in an integrating sphere. The rotation angle of the probe
beam's polarization plane is detected in the experiment. The results indicate
that the biased magnetic field, the probe light intensity and detuning, and the
cold atoms' temperature are key parameters for the MOR effect. This scheme may
improve the contrast of the rotation signal and provide an useful approach for
high contrast cold atom clocks and magnetometers.
