KROHNE Summit 8800 Vol 2 - Manual (Page 27)

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08/2013 - MA SUMMIT 8800 Vol2 R02 en
SUMMIT 8800 METERING PRINCIPLES 03
Figure 10 Coriolis meter flow principle
A tube with a fluid is brought into a sine waveform vibration. The eigen frequency with which this
occurs is directly dependent on the density of the fluid. If the fluid is flowing, a phase shift of the
vibration will occur between the inlet and outlet of the tube. This phase shift is a measure of the
velocity with which the fluid passes through the pipe.
Traditional Coriolis meters have a bent tube to maximize the Coriolis effect. With more advanced
electronics nowadays there is also straight tube Coriolis meters (see drawing).
Coriolis meters determine the mass flow, but can also determine the density. Most Coriolis
meters will also calculate the volume flow using internal temperature and pressure, but it is
recommended to use external measurements because of accuracy.
Coriolis meters typically have a dual pulse output mostly with the choice to have mass or volume
flow rate, where mass flow rate is more accurate. Because of the fact that also density, pressure
and temperature are available, most meters have also the option for a serial (modus) output, or
a (multi-variable) Hart output.