A sparkplug is an electric device used to transmit electricity from one point to another. It works much like how a bolt of lightning works. A sparkplug is more commonly found in the engines of motor vehicles. A typical plug can carry around 40,000 to 100,000 volts of electricity.
A sparkplug has eight parts namely the terminal, insulator, ribs, insulator tip, metal case/shell, seals, side electrode and central electrode. The terminal is located at the top of the plug which connects to the ignition system. On the other hand, the insulator provides insulation and support to the central electrode.
The ribs are merely for support. Some plugs are manufactured without such. The seal ensures that no leakage coming from the combustion chamber will occur. Meanwhile, the metal case removes the heat coming from the insulator and transmits it to the cylinder head. Lastly, the central electrode minimizes the RF noise to prevent any sparking.
Image source: HumbleMechanic
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