High-precision flow-oriented multi-angle reflectance sensor

The invention relates to a three-dimensional flow cell for aligning non-isometric particles in a liquid sample in two axes, comprising a feed zone for the sample containing realign not isometric particles and an outlet for the sample containing two axes oriented non-isometric particles, wherein a fluid element of the specimen with the dimensions a, b, c is converted into a stretching zone to a fluid element with the dimensions a x n, b / nxm, c / m, where a is the width, b the height, and c denote the length of the fluid element and n and m from the geometry of the flow cell are dependent constants which are positive numbers ≧ 1 represents a method for alignment of non-isometric particles in a liquid sample, the use of the three-dimensional flow cell, a reflectance sensor, which has the three-dimensional flow cell of the invention, a method for measuring the reflectance of a liquid sample contained tend not isometric particles and the use of the reflectance sensor according to the invention.