Patent ID: 6951612

Claim:
A system for monitoring separation of components in a fluid sample, comprising: a centrifuge including a rotatable rotor portion having a sample reservoir for receiving the fluid sample and a drive portion mechanically connected to the rotor portion for transmitting a rotating force to the rotor portion to separate differing density fluid sample components in the sample reservoir into radially positioned belts, wherein the rotor portion includes an extension that extends a distance beyond an outer surface of the drive portion as measured radially outward from the central axis of the centrifuge and the sample reservoir is at least partially housed in the extension, wherein the rotor portion and the sample reservoir are adapted to allow radiation to pass through at least a monitored portion of the fluid sample, wherein the sample chamber includes an outlet port for providing a path for removing the components in select ones of the belts from the centrifuge while the drive portion transmits a rotating force to the rotor portion and wherein the outlet port is positioned within the sample reservoir to at least partially coincide with the radial position of the monitored portion of the fluid sample; and a liquid density sensor assembly positioned external to the centrifuge comprising at least one radiation source for emitting radiation beams and at least one radiation detector for receiving radiation beams and in response generating a signal indicative of the received radiation beam intensity for use in determining a density of the monitored portion, wherein the radiation source and the radiation detector are aligned axially to the rotor portion and positioned on opposing sides of the extension of the rotor portion such that the beams emitted by the radiation source pass in an axial direction through the rotor portion and through the monitored portion of the fluid sample and impinge on the radiation detector.