Definition 1 of 2
Definition
The transmitting component of a remote-indicating system. The sender is mounted at the location being measured (such as a fuel tank, engine, or hydraulic line) and converts a physical quantity — fuel level, pressure, temperature, or position — into an electrical signal that is sent to a matching indicator on the instrument panel.
Plain English
A small device fitted at the thing being measured. It senses a value like fuel level or oil temperature and sends an electrical signal to the gauge on the panel so the pilot can read it from the cockpit.
Context Anchor
Seen in aircraft instrument, engine, and fuel system discussions, especially when a gauge reading is being checked or a system is being troubleshot.
Derivation
Sender comes from the verb “send,” meaning to cause something to go from one place to another. In this aviation use, the sender does not send a package or message from a person; it sends information from a system part to an instrument.
Why Pilots Care
A faulty sender produces false gauge readings that can lead to incorrect fuel management or undetected engine problems.
Intuition Check
Do not read “sender” as a person who sends something. In an aircraft system, a sender is usually a sensing device that sends information to a gauge or other unit.
Example Sentence 1
The fuel quantity sender in the left wing tank uses a float to vary resistance as the fuel level changes.
Example Sentence 2
Oil pressure sender readings are verified during engine run-up to confirm proper instrument function.