Seismic monitoring on a national scale, carried out by the National Institute of Geophysics and Volcanology (INGV) through the installation of appropriately distributed seismic-accelerometer stations, represents a fundamental requirement for characterizing seismic activity and the seismic hazard across the national territory. In this context, technological advances over recent decades, through the design and development of innovative instrumentation, have significantly improved the efficiency and reliability of seismic monitoring networks, ensuring high standards of data quality and continuity. This technical report presents the new REFTEK Wrangler-HDR (High Dynamic Range) digitizer now used by INGV. In particular, it describes the hardware features of the seismic acquisition system,...