VEGA VEGACAL 62 Profibus PA - Manual (Page 13)

13
4 Mounting
VEGACAL 62 • Profibus PA
30025-EN-130917
The max. permissible pressure is specified in chapter "Technical
data" or on the type label of the sensor.
Insulating measures, such as e.g. covering the thread with teflon tape,
can interrupt the necessary electrical connection with metal vessels.
For this reason, ground the probe on the vessel or use a conductive
seal material.
Metal vessel
Make sure that the mechanical connection of the probe to the vessel
is electrically conductive to ensure sufficient grounding.
Use conductive seals, such as those made of copper or lead, etc.
Insulating measures, such as covering the thread with Teflon tape,
can interrupt the necessary electrical connection with metal vessels.
For this reason, ground the probe on the vessel or use a conductive
seal material.
Non-conductive vessels
In non-conductive vessels, e.g. plastic tanks, the second pole of the
capacitor must be provided separately, e.g. in the form of a concentric
tube.
If possible, the capacitive probe should be mounted vertically or par-
allel to the counter electrode. This applies particularly to applications
in non-conductive products.
In cylindrical tanks, spherical tanks or other asymmetrical tank forms,
nonlinear level values are generated due to the varying distance to
the vessel wall.
Use a concentric tube in non-conductive products or linearize the
meas. signal.
If condensate forms on the vessel top, the run-off liquid can cause
bridging and hence measurement errors.
For this reason, use a screening tube or a longer insulation. The
length depends on the amount of condensate and the drain-off be-
haviour of the product.
4.2 Mounting instructions
During operation, the probe must not touch any installations or the
vessel wall. The measured value can also change if the distance to
the vessel wall changes considerably. If necessary, secure the end of
the probe (insulated).
Vessel material
Vessel forms
Condensation
Installation position