#28.Flame Detector

Flame Detectors – Monitors if the pilot light or main flame is actually lit.

Flame rod detectors are used with flame safeguard controls with gas pilots.

The flame rod and flame safeguard system use a very small amount of current.

This sensing current is actually conducted by and through the flame, which acts as a rectifier.

The flame rod sensor and the burner, which is at ground potential, are the sensing electrodes to which ac is applied..

- Electricity flows to ground in only one direction, resulting in a dc signal, which can be monitored and measured, and is applied to the input of the flame safeguard control.- The flame safeguard shuts off the fuel supply if the flame is extinguished.