Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

A measuring system based on potential difference probes is presented which makes possible the determination of very small values of the velocity in liquid metal flows. On the one hand, a large size of the sensor and a high induction of the static measuring field, respectively, and resolution on the other hand has always been a compromise. These opposite demands were countered with state of the art analog instrumentation, and by avoiding meticulously potential sources of error such as induced noise and the even more detrimental thermoelectricity. The present paper instances the flow driven by a rotating magnetic field, in which the scaling of velocity versus strength of the driving electromagnetic force was examined. The measurement of the transition from the Stokes regime to a laminar boundary one demonstrates the obtained improvement of the velocity resolution by about two orders of magnitude.