Magnetic Level Gauge

A magnetic level gauge involves the use of a permanent magnet sealed inside a closed float whose rise and fall causes the rotation of bi-coloured magnetic rollers or flappers. The float is situated inside the chamber of the instrument in contact with the process medium and is not able to be viewed from the outside. The float inside the chamber is coupled to bi-coloured magnetic rollers / flappers installed in an indicating rail which is attached to the outside of the chamber. The red colour indicates the presence of liquid while the point where the colour is white shows the level of liquid in the vessel.

For this type of instrument chemical compatibility, temperature, specific gravity (density), buoyancy and viscosity are all important in the selection and design process especially for the float. For example, larger floats may be used with liquids with specific gravities as low as 0.4 while still maintaining buoyancy.

A magnetic level gauge can be used for measuring either total or interface level and offer an alternative solution to traditional reflex / transparent gauges. Accessories such as switches / transmitters can be supplied and fitted to this type of gauge and it is not necessary to have isolation valves as there is no glass to break.