16
2.4.2.3 Launcher Orientation — Flow Application
Orient the R82 transmitter so the Polarization pattern is
aimed directly down the throat of the flume or weir.
If conduit connections are oriented 90° to the flow, set the
Launcher Adjustment to #2.
2.4.2.4 Poor Echo Strength
Poor Echo Strength has many potential causes. Following
are two initial areas for investigation.
Launcher Orientation:
Initial launcher orientation is always
parallel to tangent of the tank circumference (see Sections
2.4.2.1 & 2.4.2.2). In tall vessels and when antenna is
mounted close to the tank wall, improvement in Echo
Strength may be attained by rotating the launcher to
90 degrees.
Signal Loss:
If the Level signal is lost repeatedly at a specific
point in the vessel, it is usually a symptom that multipath
(side-wall reflections) are causing cancellation by returning
to the transmitter exactly 180° out of phase with the Level
signal. Utilize the following procedure:
• Go to transmitter screen #5 which shows both Level and
Echo Strength.
• Bring the Level up (or down) to the exact point where the
signal is repeatedly lost. Monitor the Echo Strength this
point is being approached. The Echo Strength will degrade
to a low point before it begins to increase.
• At the poorest Echo Strength slowly rotate the launcher
1–2 notches. Allow the unit to stabilize for approximately
one minute. Repeat this process until the Echo Strength
is optimized.
58-610 Model R82 Radar Transmitter
Figure 19
Internal Launcher Adjustment
Ground
Launcher
Adjustment
(+
)
(-)
Figure 20
Mounting Over Flume
