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by the number of
cycles present
span. If " x 10 M A G " is used multiply this further by 10.
Note that errors will occur for displays having only a f e w
cycles.
Using the formula:
# of cycles x " x 10 M A G " value
Freq =
Horizontal distance (div) x SWEEP TIME/DIV setting
Count cycles between this portion
Fig. 16
[EXAMPLE]
For the example, within 7 divisions there are 10 cycles.
The SWEEP TIME/DIV is 5 us. (See Fig. 16)
Substituting the given value:
Freq=
—
= 2 8 5 . 7 kHz
7 (div) x 5 (/is)
PULSE WIDTH MEASUREMENTS
Procedure:
1. Apply the pulse signal t o the INPUT jack. Set the vertical
MODE to the channel t o be used.
2. Use the VOLTS/DIV, VARIABLE and y POSITION to ad-
just the waveform such that the pulse is easily observed
and such that the center pulse width coincides w i t h the
center horizontal line on the CRT screen.
3. Measure the distance between the intersection of the
pulse waveform and the center horizontal line in divi-
sions. Be sure that the VARIABLE is in the CAL. Multiply
this distance by the SWEEP TIME/DIV and by 1/10 is
" x 10 M A G " mode is being used.
Using the formula:
Pulse width = Horizontal distance (div) x (SWEEP TIME/DIV
setting) x " x MAG lO'Value"
20
in the given time
[EXAMPLE]
For the example, the distance (width) at the center horizon-
tal line is 4 . 6 divisions and the SWEEP TIME/DIV is 0.2 ms.
(See Fig. 17)
Substituting the given value:
Pulse width = 4 . 6 (div) x 0.2 ms = 0 . 9 2 ms
PULSE RISETIME AND FALLTIME MEASUREMENTS
For risetime and falltime measurements, the 1 0 % and
9 0 % amplitude points are used as starting and ending
reference points.
Procedure:
1. Apply a signal t o the INPUT jack. Set the vertical MODE
2. Using the y POSITION control and the other controls,
3. Use the «*• POSITION control t o adjust the 1 0 % point
NOTE:
Be sure that the correct 1 0 % and 9 0 % lines are used. For
such measurements the 0 , 10, 9 0 and 1 0 0 % points are
marked on the CRT screen.
(1/10)
1
Using the formula:
Risetime = Horizontal
Adjust to the vertical scale
w i t h
Pulse length
(at 5 0 % )
Fig. 17
t o the channel t o be used.
Use the VOLTS/DIV
and VARIABLE t o adjust
waveform peak-to-peak height t o six divisions.
adjust the display such that the waveform is centered
vertically in the display. Set the SWEEP TIME/DIV t o as
fast a setting as possible consistent w i t h observation of
both the 1 0 % and 9 0 % points. Set the VARIABLE to
CAL.
t o coincide w i t h a vertical graduation line and measure
the distance in divisions between the 1 0 % and 9 0 %
points on the waveform. Multiply this by the SWEEP
TIME/DIV and also by 1/10, if " x 10 M A G " mode was
used.
distance
s e t t i n g ) x " x 1 0 M A G " value"
POSITION
Align the w a v e f o r m
w i t h the center using
A
POSITION
the
(div) x (SWEEP
TIME/DIV
(1/10)
1
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