What does a cad cell detect in an oil burner?

A cad cell in an oil burner detects light, specifically the light emitted from a flame. This device acts as a safety and monitoring component within the burner system. When the oil burner is operating, the flame produces light that the cad cell senses as a presence indicator. If the flame goes out or if there is an issue with ignition, the cad cell will not detect the appropriate light levels, prompting the burner to shut down to prevent unburned fuel from accumulating, which could lead to potentially dangerous situations.

The cad cell thus plays a crucial role in ensuring safe operation—monitoring the flame helps to avoid hazardous conditions that might arise from fuel not being properly burned. This functionality is vital for both operational efficiency and safety within an oil burner system.