Sensor for determining a liquid level for an aircraft tank, assembly of a tank and a sensor, method of using such a sensor

An aircraft comprising an assembly of an aircraft tank and a sensor for determining a liquid level for the aircraft tank, the sensor comprising:

• a closure device mounted in a port of the aircraft tank and a measuring device removably mounted on the closure device,
• the closure device comprising a liquid line configured to conduct liquid from the port of the aircraft tank and a sealing member having a body arranged with the liquid line for automatically sealing the liquid line when the measuring device is not mounted on the closure device,
• the measuring device comprising at least one pressure measuring member configured to measure a pressure difference between a liquid pressure in the liquid line and a reference pressure so as to deduce from the liquid pressure and the reference pressure a liquid level in the aircraft tank,
• the aircraft tank comprising a body with a wall having a thickness and a mouthpiece having an elongated body formed around the port, the mouthpiece being in fluidic communication with a gas phase inside the aircraft tank via a first internal gas line portion that is formed in the wall of the tank, and
• the closure device comprising a second internal gas line portion in fluid communication with the first internal gas line to supply the at least one pressure measuring member with a gas pressure for the reference pressure.