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? dSM(s) are not visible in the configurator What happens if a dSM is defective? How many filters dSF need to be installed?