The CIS-100 systems use a unique time-size mapping called Time of Transition theory to directly measure particles size. A He-Ne laser beam focused down to spot, performs circular scanning by a rotating wedge prism of the sample measurement volume. As the particles (moving or stationery) within the sample volume are individually bisected by the laser spot, interaction signals are generated. These signals are then detected by a PIN photodiode. Since the beam rotates at a constant speed, the duration of interaction provides direct measurement of each particle’s size. The interaction signals are collected by a dedicated data acquisition card and analyzed in 600 discrete size intervals. Sophisticated pulse analysis algorithms are employed to reject out-of-focus and off-center interactions. Two-dimensional shape information is essential for the true characterization of non-spherical particles and aggregates. To meet these vital needs, the CIS-100 systems use the power of image analysis. The shape analysis channel uses a CCD video camera microscope to provide an optimal image for processing. Illumination is provided by a synchronized strobe light. Acquired images are passed to a frame grabber card for analysis.