• Sigma Instruments Company

Pneumatic Level Switches

Pneumatic Level Switches are used in application where electrical switching is not recommended or electricity is not available. These systems require minimum 2 kg/cm² clean filtered air, preferably through an AFR. In Order to protect the switch assembly from contaminants, filtered and dried gas/air supply is recommended. Side Mounted(with / without cage):Buoyancy force of process liquid on a float causes the float to move with the liquid's surface. Float movement pivots a magnet into the field of a like-charged switch magnet. As the magnets repel each other, the switch magnet moves, actuating the switch.Free swinging float arm - No cavities to clog (eliminates “Float Stick”), Magnetically activated - No seals to maintain / No leaks / No fugitive emissions.

Top Mounted Float/ Displacer(with/without cage): Operation is based upon simple buoyancy, whereby a float or a spring loaded weighted displacer rises following the liquid level. A magnetic sleeve, connected to the float / displacer, moves up and operates within a non-magnetic enclosure tube. The magnetic sleeve attracts a pivoted magnet, actuating a switch mechanism located out-side the enclosure tube to give NO or NC changeover. A fall of liquid level will de-actuate the switch mechanism