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Procedure for detecting the critical flowrate state

PTB News 1.2016
Especially interesting for
  • flow measurement
  • testing laboratories

A new form of sensor technology makes it possible, in the field of gas flow measurement, to detect the critical state of nozzles.

In the field of gas flow measurement, nozzles and diaphragms are used. When a suitable pressure ratio between the inlet pressure and the outlet pressure at the nozzle is exceeded, a critical state results in which the volume flow is independent of the pressure behind the nozzle. A new form of sensor technology developed at PTB makes it possible to detect this critical state in order to significantly minimize the energy needed to create the differential pressure. Here, sound or light signals are fed through the nozzle to a detector. The signal which changes upon reaching the critical state is analyzed.
(Technology Offer 0387)

  • optimized flow measurement
  • low operating costs
  • precise analysis of the critical state


Andreas Barthel
+49 (0)531 592-8307
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