What scale do you set your meter to measure flame rectification?

To measure flame rectification accurately, setting your meter to microamperes (uA) in direct current (DC) mode is appropriate. Flame rectification is a process used in gas-fired appliances with safety ignition systems, where the presence of a flame alters the electrical characteristics of the circuit, allowing for the detection of flame.

When a flame is present, it allows a small amount of current to flow through the flame into the grounding circuit. This phenomenon generates a measurable current that indicates the flame is successfully established. The flame rectification current is typically very small, often in the microampere range. Using uA DC allows for a precise measurement of this low-level current caused by the flame detection process.

Choosing any other setting, such as mV AC, uA AC, or mA DC, would not capture the flame rectification current correctly. mV AC is too sensitive to alternating current signals that are not relevant for flame rectification. uA AC would also measure alternating signals that do not provide accurate readings in the context of flame detection. mA DC might not provide the necessary sensitivity to detect the small current that flows in flame rectification applications. Thus, uA DC is the correct setting for accurately measuring this phenomenon in