The Hawker Bubbler (Hydrostatic) Level Gauges from HMA INSTRUMENTATION are suitable for all corrosive and non-corrosive liquids. The Level Gauges feature integral continuously-rated air pumps for up to 3 m, and can be used with optional regulated air or an inert gas supply. Output is 4-20 mA, with a built-in analogue depth meter, four fully-adjustable set points, and dip tubes.
The system is designed for use in aggressive liquids that would attack an immersed pressure transducer/transmitter. Air is ‘bubbled’ into the liquid via a dip tube, with a balance chamber to smooth out pressure pulses. The output pressure from the balance chamber is fed by a nylon tube to the transducer in the controller.

The transducer’s output signal is conditioned to provide a 4-20 mA signal proportional to the depth, and also to provide an integral meter reading. Control is by means of four trip amplifiers, each providing a volt-free contact output. Larger units can be supplied for up to 30 m, complete with ancillary pneumatic gear. The control unit is normally supplied complete with a wall-mounted plastic enclosure rated to IP54.