Keysight Technologies 33210A User Manual page 357

If an average-reading voltmeter is used to measure the "DC voltage" of a
NOTE
waveform, the reading may not agree with the DC Offset setting of the function
generator. This is because the waveform may have a non-zero average value
that would be added to the DC Offset.
You may occasionally see ac levels specified in "decibels relative to 1 milliwatt"
(dBm). Since dBm represents a power level, you will need to know the signal's
RMS voltage and the load resistance in order to make the calculation.
For a sine wave into a 50Ω load, the following table relates dBm to voltage.
dBm
+23.98 dBm
+13.01 dBm
+10.00 dBm
+6.99 dBm
0.00 dBm
-6.99 dBm
-10.00 dBm
-36.02 dBm
For 75Ω or 600Ω loads, use the following conversions.
Keysight 33210A User's Guide
dBm = 10 × log (P / 0.001)
10
dBm (75Ω) = dBm (50Ω) – 1.76
dBm (600Ω) = dBm (50Ω) – 10.79
where P = V
RMS Vol tage
3.54 Vrms
1.00 Vrms
707 mVrms
500 mVrms
224 mVrms
100 mVrms
70.7 mVrms
3.54 mVrms
Tutorial
2
/ R
RMS L
Peak-to-Peak Vol tage
10.00 Vpp
2.828 Vpp
2.000 Vpp
1.414 Vpp
632 mVpp
283 mVpp
200 mVpp
10.0 mVpp
7
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