Magnetic level gauge

Magnetic level gauges may also be designed to accommodate severe environmental conditions up to 210 bars at 370 °C.

Unlike a sight glass, magnetic level gauges do not need to be transparent and can be made out of metal, which increases the durability and operating temperature range of the device.

[2] Magnetic float level sensors involve the use of a permanent magnet sealed inside a float whose rise and fall causes the opening or closing of a mechanical switch, either through direct contact or in proximity of a reed switch.

The choice of float material is also influenced by temperature-induced changes in specific gravity and viscosity – changes that directly affect buoyancy.

Moreover, the field strength as you travel around the circumference will have high and low spots as you pass between the individual bar magnets.