Tektronix P6205, Instruction Manual

Page: 50 / 74

Performance Verification
4–8
P6205 Instruction Manual
4. Measure and record as system rise time (tr
s
), the rise time of the
displayed pulse.
5. Mate the 50
W
termination adapter to the female BNC-to-GR
adapter. Disconnect the coaxial cable at the oscilloscope and
attach the mated adapters to the coaxial cable. Connect the P6205
probe to the same oscilloscope input and insert the probe tip
firmly into the termination adapter.
6. Save and then recall the waveform.
7. Adjust the oscilloscope controls to display this waveform at the
same vertical scale as the first waveform. Measure and record as
probe-plus-system rise time (tr
p+s
), the rise time of the displayed
pulse.
8. Calculate the probe rise time (tr
p
) using the equation below.
Accuracy of the approximation is limited by oscilloscope system
performance.
t
r
p
+
t
2
r
p
)
s
– t
2
r
s
Ǹ
The calculated probe rise time should be less than 467 ps. If the rise
time value exceeds this limit, use the procedure beginning on
page 4–5 to more accurately determine the probe rise time.
Bandwidth Approximation
You can calculate the approximate bandwidth from the rise time
measurement with the following equation:
BW
+
.35
t
r
NOTE . This calculation does not constitute a valid performance
verification criteria.