User Manual

Performance Ver
ification
6. Set the Channel 1 sampling head to TDR mode: press the SE TU P DIALOGS button and select the TDR tab. Refer to
the following i
llustration.
7. Set the Channel
1(C1) Polarity to positive (rising).
8. Set the Preset o
f Channel 1 on.
TDR Preset sets
Internal Clock in the Trigger menu, turns on the TDR Step in the TDR Setups menu, turns on the
channel and selects the acquisition Units in the TDR Setups menu, and sets the horizontal scale, position, and reference.
The sampling module will turn on a red light next to the SELECT channel button, indicating that TDR is activated for
that channel.
9. Turn off the display for Channel 1 so that only Channel 2 is shown on screen.
10. A d just the oscilloscope vertical posit ioning to center the signal on screen.
11. Set the oscilloscope horizontal scale to 200 ps/div and center the waveform.
12. Use the oscilloscope measurement capability to display rise time.
Increase the stability of the pulse edge measurement by using averaging, if available. Rise time is determined from
the 10% and 90% amplitude points on the waveform.
13. Recordtherisetimeast
s
. This measurement represents the rise ti me of the test system without the probe.
The following steps instruct you to assemble the test setup that includes the probe. The system and probe rise time
(ts+p) t
hat you measured in step 12 is used to calculate the probe rise time (tp) in step 14.
P6250 & P6251 Technical Reference 29