Keyvisual: VTflX - Variable Venturi Tube

VTflX – Variable Venturi Tube

For flow measurement of the compressor intake air

Operating principle

The VTflX variable Venturi tube is a flow meter based on a Venturi nozzle that works on the differential pressure principle. Different cross-sections can be set in a measuring tube through variable adjustment of the flow cross-section, thereby significantly increasing the spread of the measuring range. The VTflX 1800 combines the advantages of an increased spread with the measuring principle of the Venturi nozzle. The variable adjustment can be traced back to position measurement. The measurement uncertainty of this system is < 1%.

Range of application

The VTflX is used for measuring the flow in the intake area of the compressor on the turbocharger. A start-up calibration with certificate is done on a certified calibration test bench. The measured values are verified at the calibration institute and are traceable to the international calibration of SI units. The air-mass flow is calculated in the test bench automation system PAtools® TX based on pressure, temperature and humidity.

System characteristics

  • Technically-proven measuring principle on the differential pressure principle
  • Mechanically-robust system with compact design
  • Large spread of the measuring range (1:50)
  • High-precision differential and absolute pressure measurement
  • Direct distance measurement of the outer tube
  • Easy calibration and adjustment of pressure and temperature sensors (possible in situ)
  • Dynamic adjustment of position for inner tube (t90 < 0.8s)
  • Detection of flow direction (e. g. during surge)

    Customer benefits

    • Long-term stability
    • Reliability
    • Insensitivity to contamination
    • Low maintenance and calibration
    • Easy to use


    Variables Venturi-RohrVariables Venturi-Rohr