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The controls on a scope
can be divided into four
groups.
(1) Housekeeping
(on/off, brightness,
focus)
(2) Horizontal
(X position, X
amplitude,
time/division)
(3) Vertical (Y
position, Y amplitude,
Invert, Volts/division)
(4) Trigger/synchronisation
(level, +/-, external,
ac/dc/lf/hf, tvh/tvv)
Set any controls marked
"calibrate" to the
correct position.
Adjust the housekeeping
controls to obtain a
trace (display).
Adjust the vertical and
horizontal controls to
display a few cycles of
a waveform.
Adjust the trigger/synch
controls to make the
display stationary.
It is best to display
about two cycles and
make them as large in
height as possible.
Measure the amplitude
and periodic time (time
of one cycle). See
below.
Calculate the frequency.
In the diagram the
waveform is 4 divisions
high.
The volts/ division
switch is set to 50
mV/division.
The amplitude is
therefore 4 x 50 mV =
200 mV.
The width of one cycle
(indicated between the
two red dots) is 4
divisions.
The time/division switch
is set to 5 mS/division.
The periodic time is 4 x
5 mS = 20 mS.
Note that one cycle is
the time between the
start of a waveform and
the point where it
starts to repeat itself.
Frequency can be
calculated by dividing 1
second by the periodic
time.
Note that if the
periodic time is in mS
then 1 second has to be
expressed as 1000 mS.
1000mS/20mS = 50 Hz
The pattern of squares
is called a GRATICULE.
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