The Euratom Safeguards Directorate (ESD) has introduced into routine operation a commercial data logger for unattended data acquisition of specific forms of safeguards information. This data logger provides for a variety of input signal conditioning modules, e.g. RS-232 serial, 4-20-mA DC, temperature, pulse counting, etc., and the possibility of introducing special configuration modules. The ESD has implemented the data logger along with its data compression algorithms, thus reducing the amount of data to be stored and increasing the autonomy of the system when working in unattended mode. Other important features of the data logger are the special configuration modules and the applications software with a complete graphing environment. The data logger has been successfully implemented for the monitoring of neutron coincidence measurement systems, tank filling and environmental monitoring of instrumentation housings, and for inclusion in a concept of authentication of operator instrumentation.<<ETX>>