Table of Contents
Advertisement
Adjust to the vertical scale
with
POSITION
Rise time
Fig. 19
[EXAMPLE]
For the example, the horizontal distance is 4.0 divisions.
The SWEEP TIME/DIV is 2 /*s. (See Fig. 19)
Substituting the given value:
Risetime = 4.0 (div)x2 (^s) = 8^s
Risetime and falltime can be measured by making use of
the alternate step 3 as described below as well.
4. Use the
POSITION control to set the 1 0 % point to
coincide with the center vertical graduation line and
measure the horizontal distance to the point of the in-
tersection of the waveform with the center horizontal
line. Let this distance be D
position such that the 9 0 % point coincides with the ver-
tical centerline and measure the distance from that line
to the intersection of the waveform with the horizontal
centerline. This distance is D
distance is then D
plus D
t
ship in calculating the risetime or falltime.
Using the formula:
Risetime = (D
+ D
) (div) x (SWEEP TIME/DIV
t
2
setting)x"x 10 M A G " value
Adjust 9 0 % point to the center
and measure D
Rise time
Fig. 20
Next adjust the waveform
v
and the total horizontal
2
for use in the above relation-
2
1
(1/10)
.
2
Adjust 1 0 % point
to the center and
measure D
.
t
[EXAMPLE]
For the example, the measured D
is 2.2 divisions. If SWEEP TIME/DIV is 2 ps we use the
following relationship. (See Fig. 20)
Substituting the given value:
Risetime = ( 1 . 8 + 2.2) (div) x 2 (/ts) = 8 yes
TIME DIFFERENCE MEASUREMENTS
This procedure is useful in measurement of time dif-
ferences between two signals that are synchronized to one
another but skewed in time.
Procedure:
1. Apply the two signals to channel 1 and channel 2 INPUT
jacks. Set the vertical MODE switch to either A L T or
CHOP mode.
Generally for low frequency signals CHOP is chosen
with A L T used for high frequency signals.
2. Select the faster of the two signals as the SOURCE and
use the VOLTS/DIV and SWEEP TIME/DIV to obtain an
easily observed display.
Set the VARIABLE control to C A L position.
3. Using the • POSITION control set the waveforms to the
center of the C R T display and use the < >
control to set the reference signal to be coincident with
a vertical graduation line.
4. Measure the
horizontal distance between
signals and multiply this distance in divisions by the
SWEEP TIME/DIV setting.
If " x 10 M A G " is being used multiply this again by
1/10.
Using the formula:
Time = Horizontal distance (div) x (SWEEP TIME/DIV
setting) x " x 10 M A G " value"
[EXAMPLE]
For the example, the horizontal distance measured is 4.4
divisions. The SWEEP TIME/DIV is 0.2 ms. (See Fig. 21)
Substituting the given value:
Time = 4.4 (div) x 0.2 (ms) = 0.88 ms
- Reference signal
Time difference
is 1.8 divisions while D
t
2
POSITION
the
two
1
(1/10)
Comparison signal
Fig. 21
21
Advertisement
Table of Contents
