What is the most common type of electrostatic discharge in industry?

• A. Arc discharge
• B. Corona discharge
• C. Ground fault
• D. Spark discharge

Answer: (D)

Electrostatic discharge in industry most often happens as a spark across a small air gap when charged surfaces come together or near a grounded object. This is a brief, high-current event that neutralizes the charge in a sudden burst. It’s the common, everyday ESD you can encounter during handling of components or tools, and it’s precisely the kind of rapid breakdown across an air gap that people try to prevent with antistatic measures.

Corona discharge is a gradual ionic leakage that occurs around sharp HV points and doesn’t produce the abrupt, high-energy burst typical of ESD damage. Ground faults are unsafe leakage paths to earth and aren’t the usual discharge between charged bodies. Arc discharge is a related phenomenon with a sustained plasma channel, but in routine industry settings the brief, transient spark is far more common.