VEGA VEGAPULS 62 (≥ 2.0.0 - ≤ 3.8) Foundation Fieldbus - Manual (Page 20)

Fig. 13: Cover smooth profiles with deflectors
If there are agitators in the vessel, a false echo storage should be
carried out with the agitators in motion. This ensures that the interfering
reflections from the agitators are saved with the blades in different
positions.
Fig. 14: Agitators
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 lead to measurement errors, you should use the biggest
possible radar antennas and low frequency radar sensors (C-band).
As an alternative, sensors with guided microwave can be used. These
are unaffected by foam generation and are best suited for such
applications.
By using a standpipe, the influence of vessel installations and
turbulence can be excluded. Under these prerequisites, the meas-
urement of products with low dielectric values (from DK value 1.6) is
possible.
Agitators
Foam generation
Measurement in the
standpipe (surge or by-
pass tube)
20 VEGAPULS 62 • Foundation Fieldbus
4 Mounting
28450
-EN
-090305