15
5.1.5
Sensing Further Ahead of the Boom
Installing the sensor farther ahead of the boom is not an acceptable solution
to any performance issues. The reason is that, as the sensor is moved further
ahead, there will be an increasing height error at the nozzles. In other words,
the sensor and nozzle are at two different points in space, thus introducing an
error for all but the most level terrain. In severe terrain, this height error can
bring the nozzles close to the ground as the sensor reads over the crest of a
hill, or down into a ditch.
5.1.6
Sensor Capabilities
In order for the UC4+ Spray Height Control system to work at its maximum
level of performance, the UC4+ sensors must be returning accurate height
readings at the designed frequency. Under typical conditions, the sensors
can provide accurate height readings from 9 inches to over 120 inches, and
return many height readings in one second. The target in
SOIL
mode can be
identified through stubble, young crops, row crops, and normal trash. The
target in
CROP
mode can be identified over cereal grains, specialty crops,
and row crops. See the next section for more information on
CROP
and
SOIL
mode guidelines
There are two main steps to ensure sensor performance. The first step is
proper mounting. See
Section 3.2
on page 4 for more information on sensor
mounting. The second step is to ensure that the protective foam covers on
the sensors are kept clean, and that the ultrasonic transducer behind the foam
does not become corroded or excessively dirty. Extra foam pieces are
shipped with your kit. The transducer is a maintenance item and can be
replaced at NORAC service locations. Transducers can last from three to ten
years, depending on conditions. Refer to
Section 7
on page 36 and the
UC4+ Quick Guide for more maintenance information.
If the mouth of the sensor becomes wet, it is normal for the sensor to return
error messages until the transducer has dried off. This could include rain or
excessive overspray. Material can build up on the transducer if the sensor is
mounted too close to the spray nozzles. This is the reason that the sensor
must be mounted at least (25 cm) 9 inches in front of the nozzles. It keeps
the sensor housing out of the normal region of overspray.
In the sprayer boom application, the sensors ignore any target that is closer
than 25 cm (9 inches) from the bottom of the sensor housing. This region is
called the blanking range. Operating the sensor at heights near the blanking
range is dangerous and will affect performance because height readings can
be very intermittent. This is the reason that each sensor must be mounted at
least 25cm (9 inches) above the spray nozzles.
