What type of ignition turns off after the flame is established?

The type of ignition that turns off after the flame is established is known as interrupted duty ignition. This method is commonly used in various heating appliances, including oil burners. With interrupted duty ignition, the ignition source, such as a spark or flame, is activated to ignite the fuel-air mixture, and once the flame is successfully established, the ignition source turns off.

This approach is efficient because it conserves energy and prolongs the life of the ignition components. After the flame is detected, the system will continue to operate normally without the need for the ignition source to remain active, allowing for safer and more effective heating. In contrast, other types of ignition, such as constant duty, would keep the ignition source on continuously, which is not necessary once the flame is established. Thus, interrupted duty ignition is specifically designed for situations where continuous ignition isn’t required after flame establishment.