Abstract: A method and device are provided for determining at least one vertical position of at least one horizontally extending interface between a first component and at least one second component present in a sample tube in layers separated from one another. To this end, the device exposes the sample tube in multiplex time to light impulses having a first and a second wavelength, measures intensities of light impulses of the first and second wavelength exiting the sample tube, and analyzes the measured intensities for determining the position of the interfaces.

Abstract: The invention relates to an arrangement and a method for the analysis of body fluids (21), whereby an image recording device (30) is arranged in a low-reflection, preferably zero-reflection chamber (16), provided with an illumination device (45) and connected to an electronic image analyzer. The image recording device (30) is focused on a container (20), containing the body fluid (21) in an analysis position (22), in order to take at least one image of the body fluid (21), analyzed by means of an image analysis software which determines the quality of the body fluid (21).