Evolution of oscillograph - How did Chesf transform data into information?

A brief historical review of the implementation of the oscillographic network of Companhia Hidro Elétrica do São Francisco (Chesf), which considers the influence of technological advances in all stages of the process, from design to the current configuration of the network is presented. Some problems and their solutions implemented deserved attention, with an emphasis on software of oscillographic analysis that resulted from a Project of Research and Development developed by the Federal University of Campina Grande (UFCG).