An apparatus and method for presenting various surfaces of particles within a sample to a sensor device is provided. More particularly, embodiments of the present invention provide a pair of concentric counter-rotating surfaces and a dividing member fixed radially therebetween so as to form a scanning chamber wherein sample particles are reoriented relative to the scanning field of an adjacent sensor device by the counter-rotation of the surfaces and the consequent recirculation of the sample particles through the scanning chamber.