Patent ID: 7943386

Claim:
An apparatus for determining the volume fractions of the phases in a suspension, comprising: a body; a channel structure, which is formed in the body and comprises an inlet area and a blind channel, which is fluidically connected to and capable of being filled via the inlet area; a drive for imparting the body with rotation, so that phase separation of the suspension in the blind channel takes place by centrifugation; and a controller to control the drive, wherein the blind channel comprises such a channel cross-section and/or such wetting properties that, when filling same with the suspension via the inlet area, higher capillary forces act in a first cross-sectional area than in a second cross-sectional area, so that at first the first cross-sectional area fills in the direction from the inlet area toward a blind end of the blind channel by capillary force and then the second cross-sectional area fills in the direction from the blind end toward the inlet area by capillary force, the channel structure further comprises an overflow structure between the inlet area and the blind channel for volume dosage of the suspension, wherein the overflow structure comprises an overflow channel branching from the blind channel and extending in a partially radial direction to an overflow chamber, and the controller is configured to control the drive such that, upon completely filling the blind channel with the suspension by capillary force, the body is imparted with a rotational frequency that exceeds a breakthrough frequency of the overflow channel so that excess suspension is drawn off into the overflow chamber and a defined volume of the suspension is in the blind channel so that phase separation of the suspension in the blind channel takes place in the defined volume.