The paper presents an example of conformity assessment of novel distributed measurement system for monitoring the operation of MV power networks. The system is at prototype stage and it is made by Low Power Instrument Transformers featuring high accuracy, power quality bandwidth and allowing protection operation functions. The sensors are connected to a new Intelligent Electronic Device (IED), which implements many protection and measurement functions along with the most common communication capabilities. The presented system is going to be installed in A2A-Reti Elettriche SpA power network in Brescia, Italy. The uncertainty of some measurement function has been experimentally evaluated and compared with that obtained through simulation analysis. Results confirm that this last procedure can be effectively used as preventive uncertainty analysis for allowing the choice of proper high accurate measurement and protection systems, according to the specified applications.