Service Manual

Rev. C
Multi Pro 1200/1250 Page 8.1 -- 9 Sonic Boom System (Optional Kit)
Downward Slope in Turf Encountered
During sprayer operation with the sonic boom switch in
the automatic position (sonic boom light is illuminated),
the boom mounted sonic boom sensors continually
send impulse signals and then receive echos as the sig-
nals bounce off the turf. The electronic control unit
(ECU) determines the sensor distance from the ground
based on the elapsed time between the sensor signal
generationandthe receivedecho.Aslong as thesensor
height remains the same as the calibrated height, the
spray boom section will remain at a fixed distance from
the ground for spraying accuracy.
When a spray boom section encounters a downward
slope in the turf, the time necessary for the sensor to re-
ceive the signal echo is longer than the calibrated time-
frame. This change in time causes the ECU to energize
the appropriate power switch relay. The energized relay
providesa currentpathtotheboomactuatorcausingthe
actuator to extend and the boom section to lower. This
maintains the boom height at the calibrated distance
from the ground. Once the boom section is lowered to
the calibrated distance, the elapsed time between the
sensor signal generation and the received echo returns
to the correct timeframe and the boom stops lowering.
Theboomsensortargetdistanceisinitiated duringinitial
sonic boom calibration and is typically set at twenty (20)
inches. When in automatic mode, the booms will not
move if the target distance c hange is three ( 3) inches or
less (inner dead band). Once the target distance ex-
ceedsfive(5) inches(outerdeadband),theECU will en-
ergize the appropriate power switch relay. The
energized relay will lead to a change in boom actuator
length and ultimately a change in boom height.
Figure 25
SLOPE
A HIGHER BOOM HEIGHT IS DETECTED
SO ACTUATOR EXTENDS TO LOWER BOOM SECTION
Sonic Boom
System