What is the dielectric (nonconducting material) in a capacitance type fuel quantity indicating system?

The dielectric in a capacitance type fuel quantity indicating system is crucial for the functioning of the capacitive sensors used to measure the fuel level. A dielectric material is one that does not conduct electricity and can influence the capacitance of a capacitor when placed between its plates.

In a capacitance type fuel quantity indicating system, the fuel and air mixture within the tank contributes to the dielectric constant that dictates how the sensor behaves. As the level of fuel changes, the proportions of fuel and air also change, altering the dielectric properties and thus affecting the capacitance measurement. This value is essential for accurately indicating fuel quantity.

The other options do not accurately represent the function of dielectric within this system. The outer shell of the capacitor serves as the physical containment and may provide structural integrity but does not affect the dielectric properties. Liquid polymer mesh could serve various roles in a different context, but it does not define the dielectric in conjunction with the fuel and air in the tank.