Emerson Rosemount 5408 Reference Manual page 27

Reference Manual
00809-0100-4408
3.3.7 Nozzle requirements
In order to allow the microwaves to propagate undisturbed, the nozzle dimensions should
be kept within the specified limits as given in
Nozzle requirements for cone antenna
For best performance, the cone antenna should extend at least 0.4 in. (10 mm) below the
nozzle. If required, use the extended cone antenna versions (option code S1 or S2).
However, the antenna can be recessed in smooth nozzles up to 4 ft. (1.2 m). Note that if
the inside of the nozzle has irregularities (e.g. due to bad welding, rust, or deposit), then
use the extend cone antenna.
Figure 3-6: Mounting of the Cone Antenna
H
Table 3-5: Nozzle Requirements for Cone Antenna, in Inches (Millimeters)
Antenna size Minimum nozzle diameter (D)
1½-in. (DN 40) 1.50 (38.1)
2-in. (DN50) 1.94 (49.3)
3-in. (DN80) 2.80 (71.0)
4-in. (DN100) 3.78 (96.0)
(1) The antennas are sized to fit within schedule 80 or lower schedules.
(2) The values are valid for cone antennas without antenna extension.
(3) For liquid applications, the cone antenna can be recessed in smooth nozzles up to 4 ft. (1.2 m), but note that the
accuracy may be reduced in the region close to the nozzle.
Nozzle requirements for process seal antenna
The antenna can be used on nozzles up to 4 ft. (1.2 m). Disturbing objects inside the
nozzle may impact the measurement, and should therefore be avoided.
Rosemount 5408 and 5408:SIS Level Transmitters
> 0.4 in. (10 mm)
D
(1)
Table 3-5, Table
Recommended maximum nozzle height (H)
Antenna Antenna with air purge ring (code PC1)
5.59 (142)
5.71 (145)
5.63 (143)
6.54 (166)
Mechanical installation
February 2020
3-6, and Table 3-7.
(2)(3)
N/A
4.69 (119)
4.61 (117)
5.51 (140)
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