The appeal of magnetic level indicators (MLIs) is the ability to monitor the level within a vessel while maintaining the process within a sealed chamber. The wide variety of mounting configurations available ensure a safe and easy installation while eliminating the hazards and leaking seals of sight glasses. The availability of optional switches and transmitters increases their desirability by providing a much less expensive system than a buildup of sight glasses, alarm switches, and transmitters-all separately piped to the vessel.
Principle of Operation
Within the VLI Series chamber is a float containing an internal magnet array. A rise or fall of the fluid in the process tank corresponds to a similar change within the piping chamber. In response to the level movement, the float moves up or down accordingly.
Clamped to the piping column in total isolation from the process liquid is a visual indicator housing. It contains a series of dual color magnetic flags which couple with the float magnet array as the float moves up or down within the piping column. Float movement rotates the flags and results in a color change. The point at which the flags change color represents the level. Level is indicated or "read" by the corresponding point on the measuring scale.
VLIT Series Principle of Operation
VLIT combines the operating system of a conventional float-based VLI and with a second chamber containing an additional liquid level measurement device such as CS02 capacitance transmitter.