The company 'Diagnostico del Isolación Eléctrico, SLU' (DIAEL) arises from an investigation promoted in 2006 by 'Unión Fenosa Distribución' (UFD) in the field of partial discharges that was developed within the 'Polytechnic University of Madrid '(UPM) in close collaboration with the' Laboratorio Central Oficial de Electrotecnia '(LCOE). Such research materialized in a new PD measurement and monitoring system for High Voltage cables. Complementary investigations carried out between 2009 and 2012 have made it possible to extend the developments for the field of Cables to the area of Power Transformers and Gas Insulated Substations (GIS). In 2020 DIAEL is acquired by Ampacimon maintaining the BlueBOX technology as the product line for underground cable PD monitoring. BlueBOX technology is advised by a committee of experts with extensive experience in the field of high voltage tests and measurements, made up of university professors as well as highly qualified personnel. BlueBOX has expanded its commercial network internationally thanks to the establishment of agreements with large companies that allow it to position itself in multiple countries throughout the world.