External Cage Level Switch

SIGMA's External cage liquid level switches are very widely used for the petroleum and power industries. Anti vibration design ensures positive switch activation. Being highly versatile, cage mounted type extends to a wide range of other possible applications.
A pivoted permanent magnet end is attached to a micro switch. As the float rises following the liquid level, it raises a Magnetic sleeve (isolated inside a non magnetic enclosure (barrier) tube) into the field of the magnet causing attraction and movement across the pivot, actuating the switch. The enclosure tube provides a static seal between the switch mechanism and the float, eliminating the need for a flexing bellows seal, packing gland or other failure prone sealing elements.

When the liquid level falls, the float draws the magnetic sleeve below the magnetic field. The magnet swings out and re-actuates the switch to revert to the original position causing low level switch actuation

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