VEGA VEGASON 66 4 … 20 mA_HART four-wire - Manual (Page 22)

Fig. 14: Inflowing medium
Through the action of filling, stirring and other processes in the
vessel, dense foams which considerably damp the emitted
signals may form on the product surface.
If foams are causing measurement errors, the sensor should
be used in a standpipe or, alternatively, the more suitable
guided radar sensors (TDR) should be used.
Guided radar is not influenced by foam generation and is
particularly suitable for such applications.
If there are strong air currents in the vessel, e.g. due to strong
winds in outdoor installations, or because of air turbulence, e.
g. by cyclone exhaustion you should mount VEGASON 66 in a
standpipe or use a different measuring principle, e.g. radar or
guided radar (TDR).
Strong heat fluctuations, e.g. caused by the sun, can cause
measurement errors. In this case, you should use a sun shield.
Foam
Air turbulence
Heat fluctuations
22 VEGASON 66 - 4 ... 20 mA/HART - four-wire
Mounting
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