Trio CS-2100A, Инструкция по эксплуатации, Страница: 22 / 42

APPLICATION
[ E X A M P L E ]
For the example, the horizontal distance is 4 . 0 divisions.
The SWEEP T I M E / D I V is 2
M
s .
Substituting the given value:
Risetime = 4 . 0 (div) x 2 (/is) = 8/
IS
Risetime and falltimes can be measured by m a k i n g use of
the alternate step 3 ' as described b e l o w as well.
4 . Use the POSITION control t o set the 1 0 % point to
coincide w i t h the center vertical graduation line and
measure the horizontal distance to the point of the
intersection of the w a v e f o r m w i t h the center horizontal
line. Let this distance be D i . Next adjust the w a v e f o r m
position such t h a t the 9 0 % point coincides w i t h the
vertical centerline and measure the distance f r o m that
line t o the intersection of the w a v e f o r m w i t h the ho-
rizontal centerline. This distance is
D2
and the total ho-
rizontal distance is t h e n Di plus
D2
for use in the above
relationship in calculating the risetime or falltime.
Using the f o r m u l a :
Risetime =
(D1 + D2)
(div) x (SWEEP T I M E / D I V setting)
x " x 1 0 M A G " v a l u e
1
+ i / 1 0 )
[ E X A M P L E ]
For the example, the measured D i is 1.8 divisions w h i l e D
2
is 2.2 divisions. If S W E E P T I M E / D I V is 2/is w e use the fol-
l o w i n g relationship
Substituting the given value:
Risetime = (1.8 + 2.2) (div) x 2 (ns)= 8/is
TIME DIFFERENCE MEASUREMENTS
This procedure is useful in m e a s u r e m e n t of t i m e differences
b e t w e e n t w o signals t h a t are synchronized t o one a n o t h e r
but s k e w e d in t i m e .
Procedure:
1. A p p l y the t w o signals t o C H 1 and C H 2 and set the V
M O D E to D U A L choosing either A L T or C H O P m o d e .
Generally for l o w frequency signals C H O P is chosen
w i t h A L T used for high frequency signals.
2. Select the faster of the t w o signals as the S O U R C E and
use V O L T S / D I V and S W E E P T I M E / D I V to obtain an
easily observed display.
Set A V A R t o CAL.
3. Using * POSITION control set the w a v e f o r m s t o the
center of the CRT display and use the <«• POSITION
control t o set the reference signal t o be coincident w i t h
a vertical graduation line.
4. Measure the horizontal distance b e t w e e n the t w o sig-
nals and multiply this distance in divisions by the
S W E E P T I M E / D I V setting.
If x 10 M A G is being used multiply this again by 1 / 1 0 .
Using the f o r m u l a :
T i m e = Horizontal distance (div) x (SWEEP T I M E /
DIV setting) x " x 1 0 M A G " v a l u e
1
( 1 / 1 0 )
[ E X A M P L E ]
For the e x a m p l e , the horizontal distance measured is 4 . 4
divisions. The S W E E P T I M E / D I V is 0 . 2 m s .
Substituting the given value:
T i m e = 4 . 4 (div) x 0.2(ms) = 0 . 8 8 m s
5-5
Adjust to the vertical scale
with POSITION -
-Rise time
Adjust 90% point to the center
and measure D2.
Rise time
-Adjust 10% point
to the center and
measure Di.
Referance signal
-Comparison signal
Time differencer