Keyvisual: VTflX - Variable Venturi Tube

VTflX – Variable Venturi Tube

For flow measurement of compressor intake air

How it works

The VTflX is a high-precision measuring device for measuring the flow of compressor intake air of the turbocharger on the hot gas test bench. The measuring device operates according to the differential pressure principle and is designed as a variable Venturi tube.

The differential pressure principle is based on the static pressure difference that occurs when the flow passes through a defined constriction. The mass flow is determined from the absolute static pressure at the inlet, the static pressure in the narrowest cross-section, and the temperature.

The measurement uncertainty over the entire calibrated measuring range is less than 0,5%. An initial calibration is carried out on a certified calibration test bench (Swiss Federal Institute of Metrology, METAS). The measured values are traceable via the calibration institute to internationally supported implementations of the SI units. The measured value processing, the calculation of the characteristic quantities and the output of the characteristic quantities are carried out in the automation system PAtools TX.

System benefits

The advantages of the VTflX are a large measuring range (1:50), high accuracy and precision and resistance to contamination of the intake air. The VTflX is based on the technically proven Venturi principle, is mechanically robust and compact and can be easily integrated into the hot gas test bench.

Customer benefits

  • High accuracy
  • High reproducibility
  • High reliability
  • Suitable for dynamic measurements (t90<0.8s)
  • Detection of the surging process in the radial compressor
  • Robust design and insensitive to contamination
  • Easy calibration and adjustment of pressure and temperature sensors
  • Low maintenance requirements


Variables Venturi-RohrVariables Venturi-Rohr