Abstract : Eddy current flowmeter (ECFM) is envisaged to measure sodium velocity at core outlet in sodium fast reactors. Firstly, sodium tests in a pipe were carried out to ensure the feasibility of this detecting principle. The sensor exhibited a good behaviour the flow rate dependence of its response is linear and a particular frequency exists for which the ECFM's normalized response is temperature independent. Moreover, a numerical modelling was developed with COMSOL to assess the efficiency of the measurement in an opened flow, i.e. without a pipe confining the flow. Despite the decrease of sensitivity, the signal keeps linearity. However, the frequency for which the signal is temperature independent has vanished.