velocity ratio use of fine magnesium turnings no clear dependency of Bo on the amplitude was found (figure ). Instead, Bo depends strongly on the stroke frequency (figure ). Interestingly, application of pump D (which was operated at higher stroke frequencies) instead of pump B did not lead to an improvement in Bo for coarse magnesium turnings. Bodenstein numbers between 26 and 40 were measured, which are even lower than without oscillation (figure ). Despite the low amplitudes that can be realized with this pump, a dependency of Bo on the amplitude is recognizable, with the optimum being 50 µl stroke volume. Nevertheless, the operating range of this pump is not suited for narrowing the RTD for coarse Mg turnings and the Bodenstein numbers are close to those obtained by means of the syringe pump induced oscillation.