In the context of fire safety, what does a cad cell do?

A cad cell is a critical component in fire safety systems, specifically in oil-fired burners. Its primary function is to detect the presence of a flame. It does this by responding to the infrared radiation emitted by the flame, ensuring that the burner only operates when a flame is properly established. This functionality is essential for safety, as it prevents the burner from operating in the absence of fire, which could lead to dangerous situations such as the accumulation of unburned fuel. By ensuring that the burner is shut off if a flame is not detected, the cad cell plays a vital role in preventing fire hazards and ensuring safe operation of heating equipment.

In contrast, functions such as providing automatic extinguishing or measuring gas pressure are carried out by entirely different devices designed for those specific purposes. Adjusting oxygen levels does not pertain to the cad cell's function but is instead related to combustion control systems that maintain an optimal air-fuel mix in heating systems.