Explain about Turbine flow meter?

Turbine flow meter


Theturbine flowmeter is used for the measurement of liquid, gas and very low flow rates. It works on the basic principle of turbine.


  • It consists of a multi-bladed rotor (turbine wheel) which is mounted at right angles to the axis of the flowing liquid, as shown in Fig.
  • The rotor is supported by ball or sleeve bearings on a shaft which is retained in the flowmeter housing by a shaft-support section. The rotor is free to rotate about its axis.


  • The flowing fluid impinges on the turbine blades (rotor), imparting a force to the blade surface which causes the rotation of the rotor.
  • The speed of rotor is directly proportional to the fluid velocity, and hence to volumetric flow rate when it is at a steady rotational speed.
  • The speed of rotation is monitored in most of the meters by a magnetic pickup coil, which is fitted to the outside of the meter housing.
  • The magnetic-pickup coil consists of a permanent magnet with coil windings which is mounted in close proximity to the rotor but internal to the fluid channel.
  • As each rotor blade passes the magnetic-pickup coil, it generate a voltage pulse which is a measure of the flow rate, and the total number of pulses give a measure of the total flow.
  • The electrical voltage pulses can be totalled; subtracted and manipulated by digital techniques so that a zero error characteristic of digital handling is provided from the pulse generator to the final read out.

The K factor (i e, the number of pulses generated per gallon of flow) is given as

K = (Tk x f) / Q

K = pulses per volume unit, Tk =a time constant in min,
Q =a volumetric flow rate in gpm and f= frequency in Hz


  • No external power supply for Rotating vane and Woltman meters
  • Turbine flowmeters suitable for cryogenic liquids
  • Turbine flowmeters usable at extreme temperatures and pressures


  • Limited choice of materials
  • Only for low viscosities
  • Moving parts, wear
  • Sensitive to contamination
  • Axial flow totalizers are flow profile sensitive
  • Inlet and outlet sections required (not for rotating vane meters)
  • Affected by overloading and quick changes at high differential pressure, danger of over speeding
  • Vibration sensitive

Check out

>> Turbine Flow Meter Calibration Procedure

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