Tektronix 5441 Instruction Manual page 34

Operating Information-5441lR5441
+
:
I
I
0%
..
. . 1 .
Horizontal
4
distance
,
2. Set the Display switch on the time-base unit to either
Chop or Alt. In general, Chop is more suitable for low-
frequency signals. More information on determining the
mode is given under Vertical Display Mode in this section.
3. Set the vertical plug-in triggering switches to trigger
the display on channel 1 (or left plug-in) and channel 2 (or
center plug-in).
4. Connect the reference signal to the channel 1 input
connector and the comparison signal to the channel 2 (or
center plug-in) input connector. The reference signal should
precede the comparison signal in time. Use coaxial cables or
probes that have similar time-delay characteristics to con-
nect the signal to the input connectors.
Fig. 2-9. Measuring risetime.
5. If the signals are of opposite polarity, invert the chan-
nel 2 (or center plug-in) display. (Signals may be of opposite
5. Adjust the horizontal Position control to move the
polarity due to 1800 phase difference; if
so,
take this into
10% point of the waveform to the second vertical line of the
account in the final calculation.)
graticule.
6. Set the VoltsIDiv switches to produce about four divi-
6. Measure the horizontal distance between the 10%
sions of display
and 90% points. Be sure the variable SecIDiv control is in
the Cal position.
7. Set the time-base triggering controls for a stable dis-
play. Set the SecIDiv switch for a sweep rate that shows
7. the distance measured in step by the set-
three or more divisions between the measurement points, if
ting of the SecIDiv switch.
possible.
EXAMPLE: Assume that the horizontal distance be-
8. Adjust the vertical Position controls to bring the mea-
tween the 10% and 90% points is four divisions and the
surement points to the center horizontal reference line.
SecIDiv switch is set to 1 ps.
Use the period formula to find risetime.
horizontal SecIDiv
Risetime
=
distance X switch =(4) (1 ps)
=
4 ps
period
(divisions) setting
The risetime is 4 ps.
Time Difference Measurements
When used in conjunction with a calibrated time-base
plug-in unit, the multi-trace feature of the 5441 permits mea-
surement of time difference between two or more separate
events. To measure time difference, use the following
procedure.
1. Set the input coupling switches of the amplifier chan-
nels to either ac or dc.
9. Adjust the horizontal Position control so the channel 1
(or left plug-in) waveform (reference) crosses the center hori-
zontal line at a vertical graticule line.
10. Measure the horizontal distance between the two
measurement points (see Fig. 2-1 0).
11. Multiply the measured distance by the setting of the
SecIDiv switch.
EXAMPLE: Assume that the SecIDiv switch is set to
50 ps and the horizontal distance between measurement
points is four divisions. Use the following formula.
SecIDiv horizontal
Time Delay
=
switch X distance =(50 ps) (4)
=
200 ps
setting (divisions)
The time delay is 200 ps.
REV MAY 1982