Installation Manual

Accu-Wave Chapter 2 Hardware Installation
TN Technologies 2-3
3. There should be a clear path between the sensor and process material to avoid
false reflections. Verify that the path is clear of pipes, beams, or any intermittent
liquid sprays that could block the microwave beam. Also try to locate the sensor
to keep the beam path (approximately 18º wide) clear of the following:
− Turbulence, splashing, or waves such as those caused by filling,
recirculation, or sparging of light material entrances near the bottom of the
tank.
− Pipe entrances near the top or side of the tank.
− Agitator blade passing directly through the beam path. If this can not be
avoided, use the “agitator reject time” feature on the “Radar fine tuning”
menu, discussed in the Accu-Wave Operation Manual (717791).
− Vortices caused by baffles, drains, or any other obstructions.
4. The mounting location should also avoid horizontal structural surfaces such as
baffle support brackets, side wall joints, and so forth, because these surfaces
reflect a strong false signal. If this cannot be avoided, refer to the section “False
Echo Management” in Chapter 5 of the Operation Manual (717791).
5. If the vessel has a dome top, a good guideline is to mount the sensor away from
the vessel’s center point by at least 10% of the vessel diameter.
Note: If the sensor is mounted in the center of the vessel, the dome top will act as
a parabolic antenna, potentially enhancing “false” echoes due to multiple
reflections of the transmitted energy.
The tank’s nozzle must meet the following requirements.
1. Rod antennas: the internal diameter of the nozzle must be larger than 1 inch. For
best performance, the bottom of the stainless steel waveguide tube must be even
with the bottom of the nozzle or extend below the bottom of the nozzle.
2. Intrusive horn antennas: the internal diameter must exceed the horn diameter (3,
4, 6, or 8 inches). The nozzle must be free of burrs and other obstructions.
3. Process isolation horn antennas: The internal diameter of the nozzle section
needs to be the same along the length of the nozzle. The nozzle must be free of
weld beads, steps, burrs, or abrupt changes in nozzle diameter.
4. Nozzle must meet or exceed tank pressure requirements.
5. Align nozzle within 3º of vertical (verify this with a carpenter’s combination
level). Flange surface must be aligned within 3º of horizontal (verify this with a
carpenter’s combination level).
Dimensional Drawings
Refer to the appropriate drawings for the sensor mounting dimensions:
• Rod Antennas – refer to drawing 868656.
• Horn Antennas – refer to drawing TBD (future option).
Reduced-size copies of the drawings are provided in Appendix D.