13
58-610 Model R82 Radar Transmitter
2.4.1.3 Obstructions
Almost any object that falls within the beam pattern will
cause reflections that may be misinterpreted as a false liquid
level. Although Model R82 has a powerful Echo Rejection
routine, all possible precautions should be taken to mini-
mize false target reflections with proper installation and
orientation. See Figure 12.
2.4.1.4 Nozzles
Improper installation in a nozzle creates “ringing” which
will adversely affect measurement. Two Antenna extension
lengths are offered to allow the R82 transmitter to work
reliably in a variety of nozzles.
The Minimum Blocking Distance of 15" (380 mm) is
always measured from the bottom of the threads or face of
the flange. The related distance as measured from the end of
the antenna varies depending on the antenna extension
chosen. See Figure 13.
The narrow beam width of the 26 GHz, R82 does allow
mounting so that the antenna can be recessed inside the
nozzle. Optimally, the recessed dimension should never
exceed
2
¥
the nozzle diameter
(Schedule 40 maximum).
See Figure 13.
NOTE: If the antenna is recessed in a nozzle it is mandatory that Echo
Rejection is run to eliminate any possibility of false reflections.
2-inch (50 mm) Antenna
Maximum Recess (
m
) is 2
×
Nozzle Diameter (
d
) (Schedule 40 maximum)
(example: 2" diameter nozzle)
8-inch (200 mm) Antenna
Maximum
Liquid Level
Maximum
Liquid Level
m
d
15" (380 mm),
BSP: 16" (405 mm)
2" (50 mm)
4" (100 mm)
15" (380 mm),
BSP: 16" (405 mm)
8" (200 mm)
9" (225 mm)
3" (75 mm)
4" (100 mm)
d
Figure 12
Avoiding Obstructions
Figure 13
Using nozzle height to maximize useable tank space
