FAQs from Rohde & Schwarz

NGM Energymeter - Measurement frequency


I am using an NGM Power Supply. Can you please let me know which sample rate the internal energy meter is using to acquire the data?
Is it permanently reading with 500 kHz or only with about 10 Hz according to the refresh rate of the display?


The NGM calculates nearly all the statistic values based on a readout with 500 kSa/s. The measured values obtained in this way are then fed to an integral calculation.

For energy measurement, an internal ADC (delta-sigma) is read out with 1 kSa / s, which, however, covers a bandwidth of approximately 100 kHz. Since a delta-sigma ADC already averages using the converter principle, peaks up to this frequency would be included in the calculation. If faster peaks or their frequency components are to be recorded, then a separate evaluation of the FastLog values would be the better solution.

The highest measuring ranges (read back values in 20V / 10A range) are also recorded with only 1kSa / s.