DˇAmbrosi Nicola researcher; OPERA. Nuclear emulsions are made of micro-crystals of silver halides (AgBr) dispersed in a gelatin layer. After chemical development, fixing and washing, the path of an ionizing particle is visible as sequence of black silver grains of about 0.5 mm size. Because of the large amount of emulsions used in the OPERA experiment, itˇs necessary to implement completely scanning and measuring automatic systems. Pioneering work was made by the group of Nagoya, Japan starting from the 70ˇs. A complete application of automated systems was used in the CHORUS and DONUT experiments. ?