“…In particular, the natural convection flow regime establishes the oscillations frequencies in the order of 10-100 Hz [9,14,15,16,17] increasing for lower Pr number. Requirements for water are generally less strict but typical sampling frequencies found in literature for turbulence measurements are in the range 1-95 Hz [9,16,17] and for this reason liquid metals constraints are still taken as a reference here. As a consequence, very strict time response requirements are established for the sensor (ideally lower than 10 ms) to be able to follow the fluctuations even in the fastest case.…”