• results of a new experimental campaign in IELLLO facility, a LLE (Lead Lithium Eutectic) loop designed for transient simulation and instrumentation testing. • A type of differential pressure transducer and 3 flow meters were characterized in LLE: Vortex flow meter, Coriolis flow meter, Thermal flow meter. • The differential pressure transducers were used to characterize the pressure drops of some of the major components and the pressure head of the permanent magnet pump. • After a detailed analysis, the thermal flow meter was considered the most reliable for flow rate measurements in LLE. • A detailed uncertainty analysis was carried out to support the investigations. The experimental facility IELLLO was installed in ENEA Brasimone R.C. in 2007, aiming to support the design of liquid Test Blanket Modules that will be installed in ITER and to contribute to the development of Lead-Lithium Eutectic (LLE) technologies. IELLLO has been recently upgraded by installing instrumentation relevant for ITER application. Differential pressure transducers, a Coriolis and a thermal mass flow meters were installed in the facility. An experimental campaign was planned, setting two objectives. The first objective was to qualify the instrumentation for flowing LLE The installation of a differential pressure transducer across each flow meter made also possible to characterize the pressure drops across these instruments. The second objective of this activity was to improve the knowledge on the performances of the main components of the loop at lower mass flow rates (namely 0.5-1.2 kg/s) and to quantify their pressure drops. The investigated flow rates were chosen to be relevant for the LLE loop of the WCLL TBS (Water Cooled Lead-Lithium Test Blanket System). This work presents the results of the experimental campaign, paying particular attention to underline the lessons learned on how to correctly operate instrumentation for LLE.