Endress+Hauser Prosonic M FMU44, Руководство по эксплуатации

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Mounting Prosonic M FMU44 HART
10 Hauser
• Only mount one device per vessel: signals from multiple devices mutually affect one
another
• Determine the detection range using the 3-dB beam angle α
5.1.2 Beam angle
D
W
a
a
2
W = 2 · D · tan
A0038221
 5 Relationship between beam angle α, distance D and beamwidth diameter W
Beamwidth diameter W as a function of beam angle α and distance D.
• α: 11 °
• D
max
: 20 m (66 ft)
• r
max
: 1.93 m (6.3 ft)
The angle α is defined as the beam angle. At α, the energy density of the ultrasonic
wave reaches half the value of the maximum energy density. Ultrasonic waves are
also emitted outside the signal beam and can be reflected off interfering installations.
5.1.3 Narrow shafts, uneven shaft walls
1
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 6 Installation in narrow shafts with very uneven shaft walls
1 Venting hole
Strong interference echoes can occur in narrow shafts and in uneven conditions.
‣
Use an ultrasound guide pipe with a minimum diameter of 100 mm (3.94 in), e.g. PE
or PVC wastewater pipe
Avoid the accumulation of dirt in the pipe.
‣
Clean the pipe regularly.