How accurate is the power measurement of the dSM? digitalSTROM Support October 12, 2018 08:37 Updated Follow The specified measurement accuracy is: +/- 5 % (I ≥ 0.02 x I nominal) real power. Related articles What is the difference between a dSM11 and a dSM12? How often are the energy readings updated in the dSM? Where can I find the digitalSTROM configurator? What does the dSM measure: Active power or apparent power? Where are the dSF filters to be installed?