FAQs from Rohde & Schwarz

Accuracy of RMS Measurements

Question

I want to measure the RMS of a pulse sequence. I did some calculations so I know which range I have to expect.

Unfortunately the measurement results are to low. What is the reason for that?

Answer

The RMS measurement is done over the complete waveform, which is shown on the screen, if the gate function is not used.

If the pulses are very small, the resolution may not high enough to archive accurate results.

There are two possibilities to improve the results:

- use a faster time base, so that the pulse sequence is spread over the complete display

- increase the resolution in the acquisition menue