Xylem SDI-12 RADAR - Manual (Page 13)

Installation & Maintenance
11
The main difference between the figures on page 10, is that the radar enclosure in the second
figure is insulated from the bridge structure. Typically bridges are constructed of steel and other
conducting materials which act as very good earth grounds. The insulator in this picture could be
the concrete you are mounting the radar to or some other nonconducting surface. You can also
choose to use a piece of nonconducting material to mount the radar to. Using this type of
installation, the same rules are followed for both. You must provide a metal conducting conduit
from the enclosure all the way back to the gauge house. No earth grounding is done at the radar.
all earth ground connections are made at the gauge house. Using these techniques will help
solve many of your grounding related issues.
This type of equipment installation by its nature is ideal, because the cabling that causes many of
the grounding problems has been removed. The cable has been replaced by a radio transmitter/
receiver pair. Thus there is no common powering or grounding required between these two
systems. all the equipment at the remote end or radar installation is connected to a local battery,
and there are no long cables and conduit to deal with or grounding issues that need to be
worked out. This type of installation electrically isolates the remote radar equipment from the
datalogger equipment. Thus, lightning and other electrical events will have little effect on this
type of installation.
Grounding Your radar Using a wireless radio
radio Bridge