What is a Ground Loop?
A ground loop occurs when a circuit is earthed at two points with different potentials, letting current flow and corrupt the signal.
Ground Loop Explained
Earth potential differs across a plant, especially between buildings. Two earth connections on one signal path drive current through the signal or shield, adding offset and noise.
Fix it by earthing each signal and shield at one point only, or by isolating one end.
Calculators for Ground Loop
Frequently Asked Questions
What is a Ground Loop?
A ground loop occurs when a circuit is earthed at two points with different potentials, letting current flow and corrupt the signal.
How do I find a ground loop?
Lift one earth connection at a time and see if the error disappears, or measure the current in the shield.
Why does a grounded thermocouple cause problems?
The junction is earthed in the process, so an earthed input creates a second earth point.
Learn more on the blog
What is galvanic isolation
A practical guide on instrumentationblog.in with more detail on ground loop and how it is applied on real plants.
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