The flowmeter operates is based on the variable area principle: fluid flow raises a float in a tapered tube, increasing the area for passage of the fluid. The greater the flow, the higher the float is raised. The height of the float is directly proportional to the flowrate.

Glass Tube Variable Area Flowmeter. The flowmeter operates is based on the variable area principle: fluid flow raises a float in a tapered tube, increasing the area for passage of the fluid.

iSOLV MMT18 and MMT19 are known as Miniature Metal Tube Variable Area flowmeters.

iSOLV MT28 VA flowmeter measures volumetric flow rate of liquid and gases that operates on the float principle.