R&S RT-ZA15, Руководство пользователя, Страница: 21 / 58

Putting into Operation
R&S
®
RT
‑
ZD10/20/30
21 User Manual 1410.4550.02 ─ 05
The R&S RT
‑
ZD10/20/30 measures only differential input signals. Common
mode signals are suppressed by the probe. Therefore, the common mode
offset compensation is not directly visible on the oscilloscope screen, see
also
Chapter 5.2, "Dynamic Range and Operating Voltage Window" ,
on page 38. An incorrect common mode offset compensation can lead to
unwanted clipping effects. Measuring the common mode input voltage
using the R&S ProbeMeter is a convenient way to detect breaches of the
operating voltage window.
If supported by the Rohde & Schwarz oscilloscope, you can set the "CM offset" in
the probe settings on the instrument. For more details, see the oscilloscope's
user manual.
2.4.3 R&S ProbeMeter
The R&S ProbeMeter is an integrated voltmeter that measures DC voltages with
higher precision compared to the oscilloscope's DC accuracy. The DC measure-
ment is performed continuously and in parallel to the time domain measurement
of the oscilloscope.
High-precision measurements are achieved through immediate digitization of the
measured DC voltage at the probe tip.
The R&S ProbeMeter measures the differential and common mode DC voltages
simultaneously and without reconnecting the probe. For a definition of differential
and common mode input voltages, see
Chapter 5, "Characteristics of Differential
Probes" , on page 36.
When the R&S ProbeMeter is active, the measured values are displayed on the
oscilloscope. The R&S ProbeMeter state is part of the probe settings of the chan-
nel to which the probe is connected. For details, refer to the user manual of the
Rohde
& Schwarz oscilloscope.
Advantages of the R&S ProbeMeter:
●
Measures DC voltages of different levels, no need to adjust the measurement
range of the oscilloscope.
●
True DC measurement (integration time > 100 ms), not mathematical average
of displayed waveform.
Offset Compensation