What type of electrical current is used to measure flame rectification?

Flame rectification relies on the principle that a flame can ionize the air around it, creating a conductive path that allows for the flow of electrical current. This phenomenon is typically measured using direct current (DC). In a flame rectification system, a small amount of DC is passed through the flame, and if the flame is present, it will complete the circuit, allowing current to flow.

Using direct current is essential because alternating current (AC) would not provide a consistent flow of current through the flame; AC fluctuates and would be less effective for detecting the presence of the flame. Therefore, the use of DC ensures that a steady current can be monitored, allowing for accurate assessment of flame status. The other forms of electricity listed, such as phase and reactive current, do not pertain to this measurement context and focus on different aspects of electrical systems unrelated to flame detection.