What is one type of mechanical fuel quantity gauge?

The Bourdon tube is a type of mechanical fuel quantity gauge that utilizes a coiled tube that straightens when pressure is applied, enabling it to measure fuel levels based on the pressure difference created by the fuel's weight. As fuel level changes, the pressure changes, causing the Bourdon tube to bend and move a needle on the gauge, providing a direct reading of the fuel quantity. This design allows for a simple and effective measurement without the need for electrical components.

In contrast, electronic gauges use electrical signals to display fuel quantities and are not mechanical in nature. The vane-type transmitter is a device that operates on different principles, often involving a float mechanism but typically includes electronic elements for reading. The float gauge, another common mechanical type, uses floating devices on the surface of the fuel which move a reading arm or indicator, but the Bourdon tube specifically distinguishes itself by measuring pressure and translating that into a fuel quantity indication. Each of these other types serves similar functions but does so through different methodologies and technologies.