Vane Wheel Inline Sensors and Measuring Tubes

The principle of measurement is based on the fact that a vane wheel rotates at a speed proportional to the flow velocity of a fluid into which it is immersed. The rotational speed is almost independent of density, pressure and temperature of the medium. The sensing of the vane wheel rotation is by means of a proximity switch without the slightest braking effect on the vane wheel. By fitting a further proximity switch, sensing of the direction of the vane wheel rotation and the indication of the +/-direction of flow is made possible. Determined by its light weight, the vane wheel rotational speed adapts in milliseconds to velocity increases, even when being used in gases. All vane wheel flow sensors are calibrated on the same frequency, so that sensors of the same type are interchangeable.


Gaseous mediums


Liquid mediums




Main areas of application

stationary measurement in unpolluted gases, control measurement in particle laden gases



Measurable variable

Actual flow

Measuring ranges in stages

0.2...120 m/s



Maximum working pressure above atmospheric

1 MPa /10 bar

Working temperature range

-40 °C...+550 °C

Temperature measuring range

-?...+300 °C



Ex-protective system zone 1

EEx ia IIC T6

Ex-protective system zone 0


Ex-Schutzart Zone 20 / Kategorie 1D




Materials which come into contact with mediums

aluminium, stainless steel, titanium, ...

Smallest necessary insertion opening

15 mm

Smallest measuring tube inside diameter

40 mm



Sensor with directional sensing


Sensor with integrated temperature sensor



FA Messrohr 18,2 240

Vane Wheel Measuring Tube 18.2 mm up to 240 °C
FA Messrohr 18,2 100

Vane Wheel Measuring Tube 18.2 mm up to 100 °C
FA Messrohr 9,7 100

Vane Wheel Measuring Tube 9.7 mm up to 100 °C
FA Messrohr 9,7 240

Vane Wheel Measuring Tube 9.7 mm up to 240 °C