Interface detector for blood processing system

A blood processing system, comprising:

• a centrifuge assembly including a light-transmissive portion and a fluid processing region positioned at least partially adjacent to the light-transmissive portion;
• and
• an optical sensor system including
• at least one light source,
• a plurality of light detectors,
• a spectral beam splitter, and
• a controller, wherein
• each light source of the optical sensor system comprises a white light source that emits only multiple-wavelength, true white light directed toward the light-transmissive portion of the centrifuge assembly,
• the spectral beam splitter is configured to receive at least a portion of the white light, separate said at least a portion of the white light into a plurality of lights having different wavelengths, and direct each one of the plurality of lights having different wavelengths to a different one of said plurality of light detectors,
• the plurality of light detectors are configured to transmit signals to the controller based, at least in part, on said plurality of lights having different wavelengths, and
• the controller is configured to simultaneously determine a plurality of characteristics of a fluid in the centrifuge assembly using the signals from the plurality of light detectors.