A centrifuge blood processing system for separating fluid components comprising a separation chamber, a motor coupled to said separation chamber for rotating said chamber about a central rotation axis, a plurality of pumps for controlling fluid flow within said separation chamber, a controller in electrical communication with said pumps and said motor, said controller producing commands controlling said pumps and said motor, and a monitoring system in electrical communication with said controller and monitoring fluid in said separation chamber, said monitoring system comprising: a first light source in optical communication with said blood processing system for providing an incident light beam for illuminating an observation region on said centrifuge blood processing system, thereby generating light transmitted, scattered or both from said observation region; a light collection element in optical communication with said centrifuge blood processing system for collecting at least a portion of said light transmitted, scattered or both from said observation region; a programmable controller for providing an operational procedure for said monitoring system; a first timer limiting the duration of a period of illumination from said first light source, wherein said first light source comprises light-emitting diodes (LEDs); said system being characterized by: said controller being arranged to drive said first light source at higher than its rated power; a second timer providing a minimum period between periods of illumination, wherein said duration of illumination is limited to prevent failure of said LEDs, and wherein said minimum period between periods of illumination is selected to prevent failure of said LEDs. a first light source in optical communication with said blood processing system for providing an incident light beam for illuminating an observation region on said centrifuge blood processing system, thereby generating light transmitted, scattered or both from said observation region; a light collection element in optical communication with said centrifuge blood processing system for collecting at least a portion of said light transmitted, scattered or both from said observation region; a programmable controller for providing an operational procedure for said monitoring system; a first timer limiting the duration of a period of illumination from said first light source, wherein said first light source comprises light-emitting diodes (LEDs); said system being characterized by: said controller being arranged to drive said first light source at higher than its rated power; a second timer providing a minimum period between periods of illumination, wherein said duration of illumination is limited to prevent failure of said LEDs, and wherein said minimum period between periods of illumination is selected to prevent failure of said LEDs. said controller being arranged to drive said first light source at higher than its rated power; a second timer providing a minimum period between periods of illumination, wherein said duration of illumination is limited to prevent failure of said LEDs, and wherein said minimum period between periods of illumination is selected to prevent failure of said LEDs.