What does the dSM measure: Active power or apparent power? digitalSTROM Support October 18, 2018 07:45 Updated Follow The dSM measures active power. Related articles Does a digitalSTROM meter (dSM) have to be reconfigured after an exchange? How accurate is the power measurement of the dSM? What are the functions of each digitalSTROM terminal block? What does the cabling look like if I have several sub-distributions in a single-family house? Is there a software for commissioning a digitalSTROM system?