Tektronix TDS 820, Manual

Page: 42 / 94

Performance Tests
Performance Verification
1Ć28
H
Calculate the 10% and 90% points:
DV + V
high
* V
low
90%Ă pointĂ +Ă V
high
Ă *Ă 0.1(DV)
10%Ă pointĂ +Ă V
low
Ă )Ă 0.1(DV)
H
Press the main-menu button Reference Levels.
H
Press the side-menu button High Ref; then use the keypad to
enter the 90% voltage point calculated above.
H
Press the side-menu button Low Ref; then use the keypad to
enter the 10% voltage point calculated above.
H
Press the main-menu button Remove Measrmnt; then press the
side-menu buttons Measurement 3 and Measurement 2.
H
Set the horizontal SCALE to 20 ps.
H
Press HORIZONTAL MENU.
H
Press the main-menu button Time Base Position; then press the
side-menu Main Position.
H
Turn the general purpose knob to position the rising edge of the
waveform to the center of the screen (approximately 35 ns).
d. Measure the test signal: Read, and record for later use, the results at
the CHx Rise Time readout, which will automatically measure the rise
time of the test signal.
e.
Check against limits:
H
If your oscilloscope has delay lines (standard instrument),
CHECK that the measured rise time is
Instrument
Ri
ǒ
Observed
RiseTime
Ǔ
2
ć
ǒ
Generator
RiseTime
Ǔ
2
Ǹ
v 58.3 a Ă ps
a
Outside the 20
_
C to 30
_
C range, calculate the limits using the speci-
fication.
H
If your oscilloscope does not have delay lines (Option 1D),
CHECK that the measured rise time is
Instrument
Ri
ǒ
Observed
RiseTime
Ǔ
2
ć
ǒ
Generator
RiseTime
Ǔ
2
Ǹ
v 43.8Ă ps
f. Test all channels: Repeat substeps a through e for all channels.
3.
Disconnect the hookup: Disconnect the test hook up from the input con-
nector of the channel last confirmed.