How does a magnetic oil level gauge for transformer work and why is it important?

A magnetic oil level gauge uses a float inside the conservator or oil compartment that moves with the oil level. The float is magnetically coupled through the tank wall to an external indicator needle or flag, so the level can be read without opening the system. This design reduces leakage points and improves safety. It is important because low oil level reduces dielectric clearance and cooling, raising the risk of overheating, bushing flashover, and internal faults. Many gauges include alarm contacts for low and high levels to support protection and remote monitoring.