| 1. | a space between two electrodes, across which a discharge of electricity may take place. |
| 2. | the electrodes and the space between, considered as a unit: used in ignition systems. |
| spark gap n. A gap in an otherwise complete electric circuit across which a discharge occurs at a prescribed voltage. |
| spark gap
A gap in an otherwise closed electric circuit across which a discharge occurs at a prescribed voltage. The discharge often causes ionization of the surrounding gas and thereby very high temperatures, and can be exploited, as in spark plugs, to ignite engine fuel in a combustion chamber. |