Caratterizzazione di un sensore per la misura della densità di un sistema multifasico basato su rivelatore gamma a scintillazione per applicazioni nel campo dell'industria petrolifera

Since 1980 the oil industries are developing densitometers based on gamma rays absorption when passing through a medium. Due to the extreme conditions in which these instruments are supposed to operate, it's important to know how their response changes as a function of certain parameters. This work analyzes how the Q-Gamma densitometer designed by Pietro Fiorentini (PF) behaves in the temperature range from -30°C to 70°C. In particular, several algorithms are determined, in order to compensate the densitometer response variations caused by change in temperature. The PF Q-Gamma is composed by a 50mCi 137 Cesium radioactive source, a NaI(Tl) scintillator crystal, a PMT and dedicated electronics board. The test described in this document tries also to separate the temperature dependecy of the detector and the electronics board.