What is the resistance range established upon firing a fuel oil burner when testing a CAD Cell?

The resistance range established upon firing a fuel oil burner when testing a CAD (Cadmium) Cell is important for determining the operational status of the burner. A CAD Cell senses the presence of a flame by measuring the resistance of the light it detects.

When the burner operates and there is a good flame, the resistance typically falls within the range of 300-900 ohms. This range indicates that the flame is stable and effective in energizing the CAD Cell, allowing the control system to confirm that combustion is occurring properly. If the resistance is too high or too low, it may signal a problem such as a flame failure or improper operation of the burner.

The other ranges provided do not align with the operational characteristics of the CAD Cell during normal burning conditions. Therefore, understanding the correct range is crucial for troubleshooting and ensuring proper function of the fuel oil burner system.