Jerguson® products are also available under the Magne-Sonics® brand as required based on approved vendor specifications.
A switch mechanism is mounted inside the enclosure adjacent to the pressure tube.
As liquid rises to cover the displacer element, a buoyancy force is created equal to the weight of the liquid displaced. This force in effect is seen by the spring as a reduction in weight, causing the spring to contract, hence moving the magnet upwards inside the pressure tube and actuating the switch mechanism. On a falling liquid level, the displacer element is uncovered and the spring sees an increasing effective weight, causing the spring to extend and move the magnet to re-set the switch mechanism.
Switching is achieved with the unique “tri-magnet” system, giving the snap-action “latch-on” switching.
The following video depicts the benefits of the Tri-Magnet level switch system compared to a standard micro-switch or mercury-switch mechanism in external cage level switches: