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 does the dSM measure: Active power or apparent power? How often are the energy readings updated in the dSM? Does a digitalSTROM meter (dSM) have to be reconfigured after an exchange? What is the dSS22? What is the dSS20 for?