The JEDI (Jülich Electric Dipole moment Investigations) collaboration carries out preparations,
R&D and a first proof-of-principle measurement for the challenging project to measure permanent
electric dipole moments of charged particles using a storage ring. In the long term, the experiments
are targeted at the construction of a novel storage ring including a new polarimeter based
on inorganic LYSO crystals and low voltage Silicon Photomultipliers (SiPMs). In order to find
the best material and assembling configurations, more than 50 modules have been assembled in
different set-ups so far. Modules have first been tested in the laboratory with internal and external
radiation sources and subsequently, they have been examined under experimental conditions
employing accelerator beams. We have performed five test beam times at several different beam
energies using the new DAQ system, which was optimized for the new polarimeter. The results of
these measurements and the accumulated experience of the module production will be presented.