It is an established and reliable technique in industry for single / multiple liquid level sensing and control in open or pressurized vessels. Hermitically sealed sensors are activated (NO/NC) as the float passes them. Have IP66.
Simple and proven design operates in most liquid.
Displacer Type Level Switch is based on buoyancy principle whereby a spring is loaded with weighted displacers which are heavier than the liquid under control. Immersion of the displacer in the liquid results in a buoyancy force change, producing a spring load reduction which moves the spring there by actuating the magnetic switch which is kept inside the stem. Have IP66.
External cage type level switches are completely self-contained units designed for side mounting to a tank or vessel with threaded or flanged pipe connections. The float movement is magnetically transmitted to switch action at the desired level. Have IP66.
Can be used in high temperature upto 400 C (with cooling fins)