Proper grounding is an important step when setting up to take measurements or work on a circuit.
Properly grounding the oscilloscope protects you from a hazardous shock and grounding yourself protects your circuits from damage. Grounding Ground the Oscilloscope 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. Ground your oscilloscope by plugging its three-pronged power cord into an outlet grounded to earth ground.