text: A screw flowmeter is composed of a set of screws (also called spindles) which form with the internal structure of the flowmeters' casing a measurement chamber.
  The screw will get into rotation thanks to the medium passing through the device, which will then be transferred by the-said screws from one end to the other end of the measuring device. For this to be done, the pressure drop is essential and seen as a "necessary evil". This rotation can then be recorded by a sensor which, combined with the processing unit (software and hardware), will be able to deliver a measurement according to the flowrate, viscosity and size of the measurement chamber. ft
  Screw flowmeters are well-acknowledged for their excellent linearity (±0.001%), excellent repeatability (up to 0,006%) and accuracy (±0.1%). They have the propensity to be used as metrological international reference and/or standard by metrological institutes, due to their outstanding features and reliability. Thanks to screw meters, public and independent institutes of metrology worldwide can compare their respective work, facilities, or calibrate other flowmeters (e.g., master metering) or compare flowmeters' performance according to different measurement principles.
  List of public and independent institutes of metrology using screw flow meters as international reference and/or standard:
  *Australia
  *Austria
  *Belgium
  *Canada
  *Czech Republic
  *Denmark
  *France
  *Germany
  *Japan
  *Mexico
  *Scotland
  *Sweden
  *Switzerland
  *Taiwan R.O.C.
  *The Netherlands
  *The United Kingdom
  *Vietnam