The homogenization takes place in the homogenization device seen in Fig. 2. By applying a pressure on the hydraulic actuator the product to be homogenized flows through the narrow gap, which is created between the forcer and the seat. Forcing of the fluid through the gap creates the desired velocities, pressure fluctuation and shear forces needed to homogenize the fluid. Typical distances between forcer and seat varies between 20 and 100 μm, a typical flow rate for a 3 piston machine is 5500 l/h, this will generate high velocities due to the area contraction. The high velocity is accompanied by a low static pressure according to Bernoulli's equation, a low static pressure can lead to cavitation formation if the static pressure is below the vapor pressure. The cavitation intensity depends on the Thoma number (Th), since this will control the velocity in the gap. The action of cavitation emits sound and light and thus it is possible to measure the intensity. Experiments show that for Th-values from 0 to 0.05 the light and sound intensity emitted by the cavitation bubbles is much higher than in between 0.05 and 0.15 where the intensities drop very quickly