Using the CRO for the First Time
- Here is the place where you will have the
opportunity to run through the basic operation of a CRO
in a few easy steps.
- Later on the opportunity will arise for you to
participate in a couple of short tutorials that should be
completed using the particular hardware in conjunction
with this WWW site.
Switching the CRO On
- O.K. this may seem simple, but the first step is
simply the act of locating the power switch and turning
the CRO on.
- Seems simple but just keep it in mind that somebody
is going to have trouble doing this.
Ensuring the CRO is
Adjusting the Trace
Position and Appearance
- First we set the AC-GND-DC
for both Channels A and B to GND. (this should allow us
to see a horizontal line across the display)
- The next thing that we do is use the Mode Selector
to allow us to view channel A on the display.
- Now that we can see the position of the trace we
use both the Intensity
controls to achieve a clear appearing trace.
- Finally we move the trace into the center of the display
using the both the Horizontal Position
Control and the Vertical Position
Control corresponding to Channel A.
- Use the Mode
Selector to view the trace of
Channel B on the display.
- Repeat (d).
- Finally to check that the above steps have been
carried out correctly we can set the Mode Selection Switch
which will allow us to view both traces on the display
- As we can see, both traces are in the
exact same vertical and horizontal positions as
the diagram on the left seems to have only one
Checking that the CRO is
Connecting the CRO to the
- It is most important, when connecting the CRO to
make a circuit measurement, to remember that the CRO can
only take readings of VOLTAGES.
This means that the CRO should always be connected in PARALELL
to the circuit element over which we are trying to find
- We now need to select which device we will use to
connect the CRO to the circuit. The two devices that we
have to choose from are the X10 Probe
and the Coaxial
Cable. In almost all cases we will
use the Coaxial Cable
as the X10 Probe
is only required when we wish to make extremely accurate
Measuring the Input Signal
- O.K. now we that the CRO has been connected to
the circuit we can actually adjust the view of the signal
on the display
to allow us to make an accurate reading
- This is done by following the instructions listed
- Select the input channel that we wish to
view using the Mode
if Channel A is required the Mode Selector would
be in the CH A
position, Channel B the CH B
position and to see both of the input signals the
Mode Selector would be in the DUAL
- After selecting the input we wish to the AC-GND-DC Selector
is moved from the GND
position to the D.C.
It may seem that if an A.C. signal is being
measured, the AC-GND-DC
Selector should be set in
position. This is not neccessary unless there is
a large D.C. offset in the A.C. input. So please avoid
the temptation to use the
- At this point the Vertical Gain
must be adjusted. This is adjusted to allow the
signal to be viewed on a scale that is
me examples of how the Vertical Gain Controls
Be sure to adjust the Vertical Gain Control
that corresponds to the input channel that we are
measuring a signal with.
- The final step involves the adjustment of
Base Control. Here the
control is rotated to the right or left untill
the shape and period of the signal viewed on the
display can be observed.
is being measured the Time Base Control
does not need to be adjusted.
- Maybe you want to see examples
of Time Base adjustment
- Now that the signal can be seen at an appropriate
size on the display
we can actually find the Amplitude and Period of the
input signal. This is done in the following manner:
- D.C. Signal Amplitude
- Simply count the number of divisions
between the Zero Level and the level of the
measured signal. Then multiply this number by the
setting on the Vertical Gain Control.
signal covers 4.2 divisions with the Vertical
gain setting on 1Volt/div gives us a signal
amplitude of 4.2 Volts so the input signal is
- A.C. Signal Amplitude
- For an A.C. signal the amplidude is
usually measured on a Peak to Peak basis. So we
count the number of divisions between the
positive peak of the signal to the negative peak
of the signal and multiply this by the Vertical
Gain Control setting.
- A.C. Signal Period
- To find the period of the signal count
the number of divisions that one cycle of the
signal "covers", then multiply this by
the setting of the Time
I want a printed
copy of the above info.
Or if you wish to carry out some practical exercises
using the CRO please use the Forward button at the bottom of the
to CRO Menu
Page maintained by EIE WebMistress
Revised: Friday, 17 July 1998