Instrumentation upgrade and commissioning tests in the HLM facility

This report is focused on the experimental tests of new absolute pressure transducer (GEFRAN KE2, 0-20 bar) for heavy liquid metals to be used in the HLM (Heavy Liquid Metal) loop HELENA. The tests were performed using a small vessel filled with LBE, but with a proper flanged connection in the bottom part to install the transducer. A new strategy to minimize the instrument error was tested avoiding the temperature drift by controlling the sensor temperature independently from the vessel HLM process temperature. This strategy was successful and it allowed to fix all the technical solutions both for LBE and for Lead in terms of temperature control and to reduce the maximum instrument error to 100 mbar (0.5% of the range). This result will allow to install and operate the transducers in the HELENA loop and in other loops at the ENEA Brasimone R.C. It is an important technological development for pressure measuring in liquid metals.