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Time = Horizontal distance (div) x ( S W E E P T I M E / D I V
setting) x " x 10 M A G " value"
- R e f e r e n c e s i g n a l
T i m e d i f f e r e n c e
[ E X A M P L E ]
For the example shown in F i g . 2 3 , the horizontal distance
measured is 4.4 divisions. If the S W E E P T I M E / D I V setting
is 0.2 ms, then
Time = 4.4 (div) x 0.2 (ms) = 0.88 ms
PHASE D I F F E R E N C E MEASUREMENTS
This procedure is useful in measuring the phase differ-
ence of signals (sinusoidal, for example) of the same fre-
quency.
1. Apply the two signals to channel 1 and channel 2
I N P U T jacks.
Select the vertical
D U A L , and choose either C H O P or A L T mode.
2. Set each control for a normal display. Set the S O U R C E
switch to the signal which is leading in phase, and use
V O L T S / D I V control to adjust the signals such that they
are equal in amplitude.
3. Use the S W E E P T I M E / D I V and V A R I A B L E controls to
adjust the display such that one cycle of the signals oc-
cupies 8 divisions of horizontal display.
Use each
P O S I T I O N control to bring the signals to
the center of the screen. Having set up the display as
above, one division now represents 45° (360°/8 div).
S o , the sweep coefficient is given as a multiple of the
angle 45°/div.
4. Measure the horizontal distance between the correspond-
ing points on the two waveforms, and multiply the
sweep coefficient (45°/div).
Phase difference (deg) = Horizontal distance (div)x45°/div
28
1
(1/10)
C o m p a r i s o n signal
Fig. 23
M O D E switch
C o m p a r i s o n
s i g n a l
P h a s e d i f f e r e n c e
[ E X A M P L E ]
For the example shown in Fig. 24, the horizontal distance
is 1.7 div, which gives
Phase difference = 1.7 (div) x 45°/div = 76.5°
The above setup allows 45° per division, but if more ac-
curacy is required, the S W E E P T I M E / D I V setting may be
changed to magnify the waveform without touching the
V A R I A B L E control.
control can be readjusted.
to
With this method, the phase difference can be determined
from the
relationship
setting for 8 div per cycle and the new S W E E P T I M E / D I V
setting made for better accuracy.
Phase difference = horizontal distance of new sweep range
(div) x 45°/div '
X
Another simple method of obtaining more accuracy quick-
ly is to simply use " x 10 M A G " for a scale of 4.5°/div.
1 c y c l e = 8 d i v .
R e f e r e n c e signal
Fig. 24
If necessary, the T R I G G E R
between the S W E E P T I M E / D I V
New S W E E P T I M E / D I V setting
Original S W E E P T I M E / D I V setting
L E V E L
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