Definition
The condition in which a ferromagnetic material has been magnetized to its maximum possible level, so that increasing the strength of the applied magnetic field produces no further increase in magnetization within the material.
Plain English
The point where a piece of iron or steel is already as magnetized as it can get. Pushing harder with a stronger magnetic field doesn't make it any more magnetic.
Context Anchor
Seen in aircraft electrical and ignition-system discussions involving coils, cores, generators, alternators, relays, and transformers.
Derivation
From Latin saturare, meaning 'to fill.' A saturated material is one that has been completely filled — in this case, filled with all the magnetism it can hold.
Why Pilots Care
Many aircraft instruments and electrical components rely on iron cores that work properly only below saturation. If a core saturates, the device stops responding correctly, which can lead to inaccurate readings or reduced output from generators and transformers.
Analogy
Think of a sponge soaking up water. Once the sponge is fully soaked, pouring more water on it doesn't make it any wetter — the extra water just runs off. A saturated magnetic material works the same way with magnetism.
Grounding Statement
A magnetic core reaches saturation when extra current mostly adds heat instead of making a stronger magnetic field.
Intuition Check
Saturation does not mean the part is wet or damaged by liquid. Here it means the magnetic material has reached its practical limit for becoming more magnetized.
Example Sentence 1
If the iron core in the transformer reaches magnetic saturation, the output voltage will no longer rise in step with the input current.
Example Sentence 2
Compass deviation checks must account for parts that may have reached magnetic saturation after exposure to strong fields.