The maximum voltage measurement range of the Chroma 66203/66204/66205 digital power meters is 600 mVrms (CF = 2). If the voltage to be measured is greater than this specified measuring range, the voltage range for the two power measuring devices can be expanded up to 1200V with the upstream measuring add-on A662012. In this case, however, the frequency is limited to DC and 47 to 63 Hz. To ensure the specifications, the power meters 66203 and 66204 must be used together with the A662012. One A662012 is required for each measuring channel of the power measuring devices.