User's Manual

DRAFT
Micropilot FMR53, FMR54
Endress+Hauser V. 1, Rev. 7, 26-10-2012 35
Beam angle
a
D
W
a
D
_
=
2
2
. .
tan
W
A0016891
å 11
Relationship between beam angle a, distance D and beamwidth diameter W
The beam angle is defined as the angle
a
where the energy density of the radar waves reaches half the value
of the maximum energy density (3-dB-width). Microwaves are also emitted outside the signal beam and can
be reflected off interfering installations.
Beam diameter W as a function of beam angle a and measuring distance D:
FMR53
Beam angle a
23°
Measuring distance (D) Beamwidth diameter W
3 m (9.8 ft) 1.22 m (4 ft)
6 m (20 ft) 2.44 m (8 ft)
9 m (30 ft) 3.66 m (12 ft)
12 m (39 ft) 4.88 m (16 ft)
15 m (49 ft) 6.1 m (20 ft)
20 m (66 ft) 8.14 m (27 ft)
FMR54 - Horn antenna
Antenna size
150 mm (6 in) 200 mm (8 in) 250 mm (10 in)
Beam angle a
23° 19° 15°
Measuring distance (D) Beamwidth diameter W
3 m (9.8 ft) 1.22 m (4 ft) 1 m (3.3 ft) 0.79 m (2.6 ft)
6 m (20 ft) 2.44 m (8 ft) 2.01 m (6.6 ft) 1.58 m (5.2 ft)
9 m (30 ft) 3.66 m (12 ft) 3.01 m (9.9 ft) 2.37 m (7.8 ft)
12 m (39 ft) 4.88 m (16 ft) 4.02 m (13 ft) 3.16 m (10 ft)
15 m (49 ft) 6.1 m (20 ft) 5.02 m (16 ft) 3.95 m (13 ft)
20 m (66 ft) 8.14 m (27 ft) 6.69 m (22 ft) 5.27 m (17 ft)