Beam Angle - Endress+Hauser FOUNDATION Fieldbus Micropilot FMR51 Brief Operating Instructions

Mounting Micropilot FMR51, FMR52 FOUNDATION Fieldbus
Metal orifice plates installed at an angle to scatter the radar signals help prevent interference
echoes.
5.5

Beam angle

The beam angle is defined as the angle α at which 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.
_
2 . . tan
a
=
W
D
2
a
W
A0016891
 1 Relationship between beam angle α, distance D and beam diameter W
The beamwidth diameter W depends on the beam angle α and the distance D.
10 Endress+Hauser