Polysulfone variable area flow meter for very low flow rates of liquids and air

A variable area instrument designed to measure and monitor very low flow rates of liquids or air. Its deliberately simple construction keeps costs down while still providing a direct, at-a-glance reading. With the optional needle valve, the same instrument also becomes a straightforward flow regulator.

Features

• Measuring ranges from 0.25…1.5 l/h up to 10…80 l/h for water
• Measuring ranges from 20…80 Nl/h up to 0.5…2.4 Nm³/h for air
• ⅛" NPT female connections
• Available in polysulfone/brass or polysulfone/stainless steel
• Maximum pressure 6 bar, maximum temperature 120 °C (polysulfone)
• Accuracy ±6 % of full scale
• Needle valve available as an option

Operating principle

The medium flows upwards through the instrument and lifts a float to an equilibrium position that depends on the flow rate. The meter must be installed vertically, and the reading is taken at the upper edge of the float.