User's Guide

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Expanse XP20 User Guide

Sounding walls and more

Fixing occlusion problems

Move the sensor higher on the pole (keeping it within the rec-

ommendations in the mounting guidelines table).

Move the sensor to another spot on the freeway if possible,

away from obstructions.

If there’s a very large barrier in the median, you could do the

following:



Use one sensor on either side of the road, pointing in (be

sure to give the two sensors a 70-ft./21.3-m lateral oset and

put them on dierent RF channels).



Put two sensors on the same pole in the middle of the

median, both pointing out (put them on dierent RF chan-

nels), but this would mean they are next to the barrier in the

median and that could cause multipath problems.

Fixing multipath problems

Move the sensor if possible; make sure it is separated from

overhead signs, overpasses, tunnels, parallel walls, etc. A 30-ft.

(9.1-m) lateral separation would be ideal, but even just a few feet

can make a dierence.

Adjust the sensor’s sensitivity thresholds in the software.

Note. A good rule of

thumb is that 50%

of a vehicle must

be visible above

any barrier in order

to be detected.