spark gap

A spark gap is the space between two high-potential terminals where electrical discharges occur. This can also refer to a device that incorporates such a gap. A common application is in a spark plug, found in internal-combustion engines. A spark plug has two electrodes separated by an air gap. When a high-voltage current passes across this gap, it creates a spark that ignites the air-fuel mixture in the engine cylinder. The length of the spark gap influences the spark's energy, and the insulator's shape affects the operating temperature, which is crucial for preventing issues like carbonization or preignition.