Flow monitors using the float principle

By A Krueger, Wika Group

Published in:

Electricity+Control, December 2015 (pages 22 – 23)
Enquiries: WIKA Instruments. Tel. 011 621 0000 or email sales@wika.co.za

Read the full article on Flow monitors using the float principle in PDF format.


These robust all-rounders measure the volume flow continuously for both liquids and gases − independent of pressure and without the need for an external power supply.

Companies in the automotive industry use lasers to cut the predetermined breaking points for airbags into the vehicle dashboards. Since one of the most important safety functions of the vehicle depends on the precision of this production step, the focal lens of the laser must not be contaminated under any circumstance. Compressed air prevents any foreign particles from settling on the lens and impairing the cutting process. For the constant flow of air, flow monitors are an essential instrument. They check the volume flow of air and ensure process safety. Furthermore, downtime is also minimised.

Such an airbag laser is a typical application example of flow monitors using the float measuring principle. The method, which was first used some 100 years ago, is principally suited to applications where flow limits have to be monitored visually or electrically. Here the measured values are displayed locally on a sight glass or via a movement, depending on the operating pressure. The electrical monitoring is generally made via reed contacts which are switched by a permanent magnet within the float.


Take note

  • Liquid gas flow measurement is commonly required in industry.
  • The float principle of flow measurement is well established and suited to both visual confirmation of flow as well as electronic sensing.
  • Float instruments are robust, responsive and cost effective.