Table of Contents
Advertisement
5. Position the display to place the time-measurement
points on the center horizontal graticule line (see Figure 4-5).
6.
Measure the Horizontal distance between the time-
measurement points.
7.
Calculate time duration using the following formula:
Time
Duration
horizontal
distance
x
(division)
A SEC/DIV
switch
setting
magnification factor
EXAMPLE: The distance between the time measurement
points is 8.3 divisions (see Figure
4-5),
and the A
SEC/DIV switch is set to 2 ms per
division.
The X10
Magnifier is off (knob in).
Substituting the given values:
Time Duration
=
8.3 div x 2 ms/div
=
16.6 ms
Frequency
The frequency of a recurrent
signal
can be determined
from its time-duration measurement as follows:
1 . Measure the time duration of one waveform cycle
us-
ing the preceding
Duration" measurement procedure.
2.
Calculate the reciprocal of the time-duration value to
determine the frequency of the
waveform.
EXAMPLE: The signal in Figure 4-5 has a time duration
of 16.6
ms.
!
100
..
.
..
J
,.I
..
,,
....
I
I
.
,,
.
/
~
.
.
.
,
.
...
....
.
.
\
J.
1
I
\
'
L
....
....
.
...
."\..
~
...
...
HORIZONTAL
DISTANCE
C4207•16
Figure
4-5.
Time d uration.
Operating Procedures-2215A
Operators
Calculating the
reciprocal
of time
duration:
1
1
Frequency
=
time duration
16.6 ms
=
60 Hz
Rise
Time
Rise-time measurements use the same methods as time
duration,
except
that
the measurements are made between
the
10%
and
90%
points of the low to high transition of the
selected waveform (see Figure 4-6). Fall time is measured
between the 90% and
10%
points of the high to low transi-
tion of the waveform.
1. Preset instrument controls and obtain a baseline
trace.
2. Apply an exact 5-division signal to either vertical-
channel input connector and set the
VERTICAL
MODE
switch to display the channel
used.
3.
Set
the appropriate
VOLTS/
DIV switch and variable
control for an exact 5-division display.
4.
Vertically position the trace so that the zero reference
of the waveform touches the 0% graticule line and the top of
the waveform touches the 100% graticule line.
5.
Horizontally
position
the display so the
10%
point
on
the waveform intersects the second vertical graticule line.
I
T
.i.
...
....
I
"
t
S IG
N
AM PLIT
~
L
UDE
_L
h .
t::
u
I
--
( e')
....
...
...
.
-
~
A
'
/
~
T
/
V
V
....
....
....
...
.
....
HORIZONTAL
D ISTANCE
.
...
-
....
·-
-
MEA
SURE
FRO
M
TIM
E
TO
@
.. ce>--
.
...
··
·•
-
C4207•17
Figure 4-6. Rise time.
4-5
Advertisement
Chapters
Table of Contents
