VEGA VEGAFLEX 61 Profibus PA - Manual (Page 12)

keep in mind that measurement down to the tip of the probe is not
possible. The exact value of the min. distance (lower dead band) is
stated in chapter "Technical data".
Fig. 3: Vessel with conical bottom
Plastic vessel/Glass vessel
The guided microwave principle requires a metal surface on the
process fitting. Therefore use in plastic vessels etc. an instrument
version with flange (from DN 50) or place a metal sheet (ø > 200 mm/
8 in) beneath the process fitting when screwing it in.
Make sure that the plate has direct contact with the process fitting.
In bypass tubes of plastic, a metal screen must be provided on the
outside. You can glue metal foil, for example, on the outside along the
entire length of the tube. This metal screen must be connected to the
ground terminal on the instrument.
When installing rod or cable probes without metal vessel wall, e.g. in
plastic vessels, the measured value can be influenced by strong
electromagnetic fields (emitted interference according to EN 61326:
class A).
In this case, use a probe in coax version.
Vessel type
12 VEGAFLEX 61 • Profibus PA
4 Mounting
31835
-EN
-100426