Micropilot S FMR533 4 to 20 mA HART
Mounting
Hauser
9
2.3.5
Beam angle
The beam angle is defined as the angle
α
where the energy density of the radar waves reaches
half the value of the maximum energy density (3dB-width). Microwaves are also emitted outside
the signal beam and can be reflected off interfering installations.
Beamwidth diameter
W
is function of antenna type (beam angle
α
) and measuring distance
D
:
"
Caution!
Make sure that
only one
tank wall (
not two
tank walls) is directly hit by the radar beam!
2.3.6
Measuring conditions
• The measuring range begins where the beam hits the tank bottom. Particularly with dish
bottoms or conical outlets the level cannot be detected below this point.
• For
overspill protection
, it is possible to define a safety distance
(SD)
additionally to the
blocking distance
(BD)
.
• Depending on its consistence, foam can either absorb microwaves or reflect them off the foam
surface. Measurement is possible under certain conditions.
• The smallest possible measuring range
B
depends on the antenna version (see Fig.).
parabolic
L00-FMR53xxx-14-00-00-xx-003
Beam angle
α
7°
Gauge Reference height
(GRH)
recommended distance from
the tank wall (W/2)
3 m (9.8 ft)
0,2 m (0.7 ft)
6 m (20 ft)
0,4 m (1.3 ft)
9 m (30 ft)
0,6 m (2 ft)
12 m (39 ft)
0,7 m (2.3 ft)
15 m (49 ft)
0,9 m (3 ft)
20 m (66 ft)
1,2 m (3.9 ft)
25 m (82 ft)
1,5 m (4.9 ft)
38 m (125 ft)
2,3 m (7.5 ft)
40 m (131 ft)
2,4 m (7.9 ft)
D
W/2
