VEGA VEGAPULS 68 (≥ 2.0.0 - ≥ 4.0.0) 4 … 20 mA_HART - four-wire - Manual (Page 25)

25
4 Mounting
VEGAPULS 68 • 4 … 20 mA/HART - four-wire
36536-EN-121011
max. 50 mm (1.97"
)
1
2
3
Fig. 21: Mounting of the instrument with insulated vessels.
1 Electronics housing
2 Distance piece
3 Vessel insulation
For level measurements in concrete silos, the sensors are often
mounted in protective boxes. These boxes can be for example metal-
lic, closed subsurface enclosures.
1 2
Fig. 22: Mounting of the instrument in an subsurface enclosure
1 Subsurface enclosure
2 Concrete bottom
For this application, the minimal amounts of stray radiation from the
sensor can be reflected and strengthened by the walls of the subsur-
face enclosures. In the case of sensors with plastic housings, this can
lead to coupling disturbances. This can be avoided by using a sensor
with aluminium or stainless steel housing.
The silo walls of multiple chamber silos are often made of profile
walls, such as e.g. profile sheeting, to ensure the required stability. If
the radar sensor is mounted very close to a heavily structured vessel
wall, considerable false reflections can be generated. Hence the sen-
sor should be mounted at a large distance from the separating wall.
The optimal mounting position is on the outer wall of the silo with the
sensor directed towards the emptying aperture in the silo center.
Installation in subsurface
enclosures
Mounting in multiple
chamber silo