VEGA VEGAPULS 56K - Manual (Page 12)

12 VEGAPULS 56K
22915-EN-041227
Heat insulation
Heat insulation
In case of process temperature of more than
200°C an insulation on the rear of the flange is
necessary to keep radiated heat away from
the sensor electronics.
The best would be to incorporate the sensor
insulation into the vessel insulation and insu-
late up to approx. the first pipe segment.
40°C
60°C
100°C 240°C
350°C
Vessel insulation
max. 350°C
Emission cone and false echoes
The radar signals are focused by the an-
tenna system. The signals leave the antenna
in a conical path similar to the beam pattern
of a spotlight. This emission cone depends
on the antenna used.
Any object in this beam cone will reflect the
radar signals. Within the first few meters of
the beam cone, tubes, struts or other installa-
tions can interfere with the measurement. At a
distance of 6 m, the false echo of a strut has
an amplitude nine times greater than at a
distance of 18 m.
At greater distances, the energy of the radar
signal distributes itself over a larger area,
thus causing weaker echoes from obstruct-
ing surfaces. The interfering signals are
therefore less critical than those at close
range.
If possible, orient the sensor axis perpen-
dicularly to the product surface and avoid
vessel installations (e.g. pipes and struts)
within the 100% emission cone. If possible,
provide a "clear view“ to the product inside
the emission cone and avoid vessel installa-
tions in the first third of the emission cone.
Optimum measuring conditions exist when
the emission cone reaches the measured
product perpendicularly and when the emis-
sion cone is free from obstructions.
Mounting and installation