Float-type flow meter and flow switch with cylindrical tube and reed contact, CSA approved

Flow meter and flow switch for liquids that rethinks the classic float instrument: instead of a tapered tube it uses a patented cylindrical metering tube with tapered openings around its circumference. This leaves a constant annular gap between float and tube, which considerably reduces the effect of dirt on the measurement and removes the usual float guidance problems.

Features

• Measuring/switching range from 0.25…1.25 l/min to 10…130 l/min (water)
• Female connections from G ¼ to G 1¼ or ¼" to 1¼" NPT
• Materials: brass, stainless steel
• Maximum pressure 10 bar, maximum temperature 100 °C
• Accuracy ±4 % of full scale
• Bistable reed contact in a height-adjustable housing, hermetically separated from the medium
• Version with two reed contacts
• cCSAus approval

Operating principle

The flow lifts the float, which contains a permanent magnet. When the magnetic field reaches the external reed contact, the contact closes; above the threshold the float rises to a stop that keeps it within the magnet's range, so the contact stays closed and switching is bistable. The instantaneous value in l/min is read on the tube at the upper edge of the float.

Applications

Monitoring and measuring the flow of liquids that may not be perfectly clean; the contact housing also protects it in aggressive environments.