TeeJet 844 Sprayer Control - Manual (Page 25)

23
Speed Sensor Type
Default = 250
Note: During Speed Calibration, the 844 will automatically sense whether
a Wheel Speed or Radar Speed Sensor is being used.
While in the Speed Calibration Programming Step, the symbol will be
flashing at the top of the display. The programmable value (250) will be displayed
in the lower right corner of the display.
PROXIMITY/MAGNETIC PULSES
The speed sensor needs to be calibrated in order to provide the proper speed
and area readings. The value for this step is the number of pulses generated by
the speed sensor in 300 feet (100 meters). This value can be determined by
automatic calibration while driving exactly 300 feet (100 meters), or by entering
the number manually.
Automatic Calibration:
To automatically calibrate the speed sensor, mark off a distance of exactly 300
feet (100 meters). While still in the speed calibration program step, position your
sprayer at the beginning of your 300 foot (100 meter) course and press the
and keys simultaneously to clear the contents of the display and to activate
the auto calibration mode. When the auto calibration mode has been activated,
CAL will be displayed at the lower right of the display. Next, press the key once
to begin the calibration process. Now drive the course and the 844 will count the
pulses as the sprayer moves. The speed at which you drive over the course is
not important. Stop the sprayer at exactly 300 feet (100 meters) and press the
key to validate the number in the display. The speed sensor is now
properly calibrated.
Note: Once the auto calibration mode has been activated, no other
functions of the 844 are possible until the console receives speed impulses
for calibration. To deactivate the auto calibration mode, depress the
key twice.
During the automatic calibration step, the 844 automatically senses whether a
magnetic sensor or radar ground speed sensor is installed. If you prefer to enter
the speed value manually, refer to the following instructions.
Manual Calculation:
To manually calculate the proper value for Wheel Speed Sensor pulses, you
need to know the circumference of the wheel to which the sensor is mounted. It
can be measured by marking the tire and measuring the distance covered as
that mark makes one full revolution. Then use the following formula:
3600 x {# magnets on wheel (usually 2)}
i.e.
3600 x 2
= 240
___________________________________ ________
Wheel Circumference in inches 30
10,000 x {# magnets on wheel (usually 2)}
i.e.
10,000 x 2
= 250
___________________________________ ________
Wheel Circumference in cm 80
The result can be entered as an alternative to using the automatic calibration
method. Use the or keys to adjust the value. Press the key to validate
the value and advance to the next programming step.
CALIBRATE
SPEED