A flame rollout sensor detects the presence of flame where?

A flame rollout sensor is designed to monitor areas where flame is not supposed to be present and provide safety by detecting unusual flame activity outside the combustion chamber. Its primary function is to enhance safety by identifying flame that has escaped the combustion chamber due to a malfunction, such as a blocked vent or improper air and fuel mixing.

When the sensor detects a flame in areas where it shouldn't be, like outside the combustion chamber, it triggers safety mechanisms to prevent potential hazards, such as fires or explosions. This is why the choice indicating the detection of flame outside the combustion chamber is correct, as it highlights the sensor's role in ensuring that combustion occurs safely and as intended within the system.