Operating instructions
Operating
Instructions-71380
The
following
information
describes
procedures
and
techniques
for
making
basic
time
measurements
with
the time-base
unit
installed
in
a
Tektronix
7700-,
7800-,
or
7900-series
oscilloscope
.
These
procedures
provide
enough
detail
to
enable the
operator
to
adapt
them
to
other
related
time
measurements
.
Contact
your Tektronix
Field
Office
or
representative
for
assistance
in
making measurements
that
are
not
described
in
this
manual
.
Since
time
is
a
function
of
the
sweep
rate
and
the
horizon-
tal
distance
(in
divisions)
that
the
sweep
travels
across
the
graticule
in
a
calibrated-sweep
oscilloscope
system,
the
time
interval
between
any
two
points
on
a
waveform
can
be
accurately
measured
.
The
following
procedures
provide
methods
to
measure
some
of
the
more
common
time-
related
definable
characteristics
of
a
waveform
such
as
period,
frequency,
rise
time,
fall
time,
and
pulse
width
.
The
procedure
for
each
of
these
measurements
is
essentially
the
same,
except
for the
points
between
which
the
measure-
ments
are
made
.
The
time
interval
between
any
two
selected
points
on
a
displayed
waveform
can
be
measured
with
basically
the
same
technique
.
Period
and
FrequencyMeasurements
Perform
the following
procedure
to
measure the
period
and
determine
the
frequency of
a
displayed
waveform
:
1 .
Install
the time-base
unit
in
a
mainframe
horizontal
compartment
(either
A
or
B
horizontal
in
a
four-compart-
ment
mainframe)
.
2
.
Connect
the
signal
to
be
measured
to
the
vertical
unit
input
.
3
.
Set
the
mainframe
horizontal-
and
vertical-mode
switch-
es
to
display
the
time
base
and
vertical
units
.
(Check
that
the
time
base
VARIABLE
(CAL
IN)
control
is
pushed
in
and
the
HOLD
OFF
control
is
in
the
MIN
position
.)
4
.
Set
the
TRIGGERING
switches
and
LEVEL
control
for
a
stable
display
(see
General
Operating
Information
for
selecting
proper
triggering)
.
5
.
Set
the
vertical
deflection factor
and
position
control
for
about
a
5-division
display,
vertically
centered
on the
graticule
.
6
.
Set
the
TIME/DIV
switch
and
POSITION
control
for
1
complete
cycle
displayed
within
the
center
8
graticule
divi-
sions
as
shown
in
Figure
1-6
.
1-
1
0
TIME-INTERVAL
MEASUREMENTS
APPLICATIONS
7
.
Measure the
horizontal distance
in
divisions
over
1
com-
plete
cycle
of
the displayed
waveform
(see
Figure
1-6)
.
8
.
Multiply
the
horizontal distance
measured
in
Step 7 by
the
TIME/DIV
switch
setting
.
(Divide
the
answer by 10
if
sweep
magnification
is
used
.)
Example
:
Assume
that
the
horizontal distance
over
1
com-
plete
cycle
is
7
divisions,
and
the
TIME/DIV
switch
setting
is .1
ms
(see
Figure
1-6)
.
Using
the
formula
:
Period
=
Horizontal distance
X
TIME/DIV
setting
Magnification
Substituting
values
:
Period
=
7
X
0
.1
ms
=
0
.7
millisecond
1
100
. . .
90
10
MENEM
ENEEMENEW
100MILWEENtWO
-
0
4
ONG
NN
NO
N
N
N
IN
M
WANNEWNSONFAN
HMMMMMMEMM
NEE
MOORE
1
FREQUENCY
=
PERIOD
MEASURE
HORIZONTAL
DISTANCE
FROM
ATOB
1985-10
Fig
.
1-6
.
Measuring
the
period
and
determining
the
frequency
of
a
displayed
waveform
.