Hardi HC 5500 SPRAY BOX III, Instruction Book

Page: 44 / 84

7 - Menu 3, Calibration
44
Menu 3.1.1.1 Constant
The theoretical speed constant, pulses per unit (PPU), is calculated from
this formula:
A = number of metal protrusions in the speed ring inside the wheel, which the speed sensor records during one full turn of
the wheel. The sensor flashes once for every metal protrusion on the speed ring, when the wheel is turning.
B = the outer circumference of the sprayer’s wheels in metres.
Example:
Wheel circumference = 6 meters, number of sensor flashes = 40, resulting in a PPU value of 6.667.
÷
NOTE! The default value is 6.000, when the speed sensor is fitted on the sprayer.
÷
NOTE! For more about the speed ring, see the section “Speed sensor for the sprayer” in chapter 4.
Menu 3.1.1.2. Practical
Practical calibration of speed is done by driving a measured distance
and correcting the display, so that the actual and the calculated
distances are the same. Calibration should take place in the field with a
half full tank and normal working pressure in the tires in order to obtain
the real “working radius” of both wheels.
Calibration method
1. Measure a distance not less than 75 meters.
2. Park the tractor at the start of the measured distance.
3. Press . When zero distance [ 0 m ] shows, drive the distance.
4. Press when finished driving.
5. Correct the distance shown on the display with the or to
read the actual distance.
6. Press to confirm. The PPU value is now adjusted.
μ
ATTENTION! The PPU value should be readjusted if you:
•
change the tire pressure
•
change to a different size of tires on the sprayer.
÷
NOTE! Use the table in the back of this book to record your values for later use.
PPU =
A
B
CONSTANT
06.000 PPU
3.1.1.1
SPRAYER
Practical
3.1.1.2
PRACTICAL
Measured
0 m
3.1.1.2