Calibrating A Gain/Phase Measurement - Omicron Lab Bode 100 User Manual

Calibration

8.2.2 Calibrating a Gain/Phase measurement

In this section you learn how to calibrate a gain measurement in the Gain/Phase measurement
mode.
The Gain/Phase measurement mode uses Channel 1 and Channel 2 of Bode 100 to measure the
transfer function of a DUT. Channel 1 must be connected to the input of the DUT and Channel 2 to the
output of the DUT. The transfer function of the DUT (complex gain) is then measured by dividing the
voltage at Channel 2 by the voltage at Channel 1.
The cables or probes that connect Channel 1 and Channel 2 to the DUT introduce a gain and phase
shift to the measurement signal.
The connection introduces a measurement error if the gain and phase shift of the two probes or cables
is not identical.
A gain respectively Thru calibration removes the gain and phase error that is caused by non-similar
probes or connections.
The following pictures show a typical gain calibration setup with BNC cables. Both channels are
connected to the same signal.
Figure 8-2: Thru calibration setup for gain/phase measurement with BNC cables.
The following picture shows a typical gain calibration setup using external voltage probes. Both probes
must be connected to the same signal during Thru calibration.
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