Tektronix T912 - Page 24

Operating
Instructions—
T912
CHANNEL
1
CHANNEL 2
MEASURE
TIME FROM
ATO B
HORIZONTAL
DIFFERENCE
465/DM-0-15
Fig, 2-11.
Phase
difference.
Substituting the
given values;
8.
Multiply
the
measured
distance (in divisions)
by
45°/division (sweep rate) to obtain the
exact
amount of
phase
difference.
Time
Duration
Horizontal
distance
(divisions)
^
SEC/DIV
setting
Example:
Assume
a horizontal
difference
of
0.6 division with a
sweep
rate of 45°/division as
shown
in
Fig.
2-11.
Time
Duration
8.3
divisions
X
2
ms/division
Time
Duration
16.6
ms
(milliseconds)
and
Substituting
the
given values:
Phase
_
Q g division
Difference
Phase
Difference
X 45'’/division
=
27°
Frequency
Frequency
1
time
duration
1
16.6 ms*
60 Hz
"16.5
ms
=
.0166
second.
Time Duration
and
Frequency
Measurements
To find the
time
duration
between two
points on
a
waveform, multiply
the
horizontal
distance (in divisions)
between the two
points by
the SEC/DIV
switch
setting.
Frequency (in hertz) is
the reciprocal
of
the time duration
of one cycle
(in seconds).
Risetime
Measurements
Risetime
measurements
are
made in the same
manner
as time
duration
measurements,
except the
measure-
ments
are made
between
the 10% and
90%
points of the
waveform's
amplitude
(see
percentage
markings on the
left edge
of
the graticule).
Use the
following
procedure to measure
risetime:
Example;
The horizontal distance measured
is 8.3
divisions (see
Fig.
2-12).
The
SEC/DIV
switch is
set to
2
ms.
1 ,
Adjust the
VOLTS/DI
V and
VAR controls
for a display
amplitude of
exactly five
divisions.
2. Adjust the
vertical
POSITION
control so that the
display
bottom
just touches
the
0%
graticule
line and
the
display
top
just touches
the 100%
graticule
line (see Fig.
2-
13).
2-12
REV. A APR 1977