VEGA VEGAPULS 66 (≥ 2.0.0 - ≥ 4.0.0) enamel Profibus PA - Manual (Page 17)

17
4 Mounting
VEGAPULS 66 enamel • Profibus PA
36529-EN-121011
If large vessel installations such as struts or supports cause false
echoes, these can be attenuated through supplementary measures.
Small, inclined sheet metal baffles above the installations scatter the
radar signals and prevent direct interfering reflections.
Fig. 11: Cover smooth profiles with deflectors
If there are agitators in the vessel, a false signal suppression 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. 12: 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 are causing measurement errors, the biggest possible radar
antenna should be used.
As an alternative, sensors with guided microwave can be used. These
are unaffected by foam generation and are best suited for such ap-
plications.
When using a surge pipe in a vessel, influences from vessel installa-
tions and turbulences can be excluded. Under these prerequisites,
the measurement of products with low dielectric values (ε
r
value
≥ 1.6) is possible. In very adhesive products, measurement in a surge
pipe is not recommended.
Agitators
Foam generation
Measurement in a surge
pipe