Tektronix XYZs, Manual

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45
Operating the Oscilloscope
Setting Up
This section briefly describes how to set up and start using an
oscilloscope – specifically, how to ground the oscilloscope, set the
controls in standard positions, and compensate the probe.
Proper grounding is an important step when setting up to take measure-
ments or work on a circuit. Proper grounding of the oscilloscope protects
you from a hazardous shock and grounding yourself protects your circuits
from damage.
Ground the Oscilloscope
To ground the oscilloscope means to connect it to an electrically
neutral reference point, such as earth ground. Ground your oscilloscope
by plugging its three-pronged power cord into an outlet grounded to
earth ground.
Grounding the oscilloscope is necessary for safety. If a high voltage
contacts the case of an ungrounded oscilloscope – any part of the case,
including knobs that appear insulated – it can give you a shock. However,
with a properly grounded oscilloscope, the current travels through the
grounding path to earth ground rather than through you to earth ground.
Grounding is also necessary for taking accurate measurements with your
oscilloscope. The oscilloscope needs to share the same ground as any
circuits you are testing.
Some oscilloscopes do not require separate connection to earth ground.
These oscilloscopes have insulated cases and controls, which keeps any
possible shock hazard away from the user.
Ground Yourself
If you are working with integrated circuits (ICs), you also need to
ground yourself. Integrated circuits have tiny conduction paths that can
be damaged by static electricity that builds up on your body. You can ruin
an expensive IC simply by walking across a carpet or taking off a sweater
and then touching the leads of the IC. To solve this problem, wear a
grounding strap, as shows in Figure 64. This strap safely sends static
charges on your body to earth ground.
XYZs of Oscilloscopes
Primer
C
Figure 64. Typical wrist-type grounding strap.