Brandt SB4000, Operator'S Manual

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4.7 SPRAYER CALIBRATION
This calibration is performed to ensure a correct sprayer application rate, based on accurate ground speed and
volume sprayed information.
NOTE: This calibration is not required if you are using auto-rate controller systems. Refer to the Operator’s
Manual for calibration information.
Calibration is not a one-time occurrence. Sprayers should be calibrated again seasonally and periodically during
the season, particularly when changing chemicals.
There are three steps to the sprayer calibration:
Step 1: Determine Your Actual Tractor Ground Speed
NOTE: Due to wheel slippage, your actual speed (determined from Fig. 4.6) may differ from the tractor speedometer
reading (especially if the speedometer reading is taken from a drive wheel).
1. Physically mark a distance of at least 100' (30.5 m) in the field to be sprayed (longer distances provide greater
accuracy).
2. Drive the tractor at a steady speed past the marker. Record the tractor rpm.
3. Record the time required to travel the measured.
4. Compare the travel time recorded above to the time (listed in Fig. 4.6 for your combination of speed and
distance. If the actual time required is different than the time shown in the table, adjust the engine rpm to arrive
at your desired ground speed.
5. Repeat the procedure to confirm the actual ground before spraying.
Step 2: Measure the Volume Sprayed Over a Known Area
1. Clean the nozzle tips (refer to Section 5.5, Nozzle Cleaning). This will ensure accuracy.
IMPORTANT: To prevent nozzle damage, never use a metal object to clean nozzle orifices. Use a plastic or
wooden probe.
2. Fill the spray tank to the neck WITH WATER ONLY. Mark the level of the water.
3. Spray over a known 1/4-mile or 1/2-mile (400 m to 800 m) distance at the sprayer pressure and speed to be
used on the field.
4. Record the volume necessary to refill the spray tank to the marked level. This will be the amount sprayed over
the 1/4-mile or 1/2-mile (400 m to 800 m) distance.
5. Refer to Fig. 4.7 for the actual area sprayed by your unit. The table provides the actual acres or hectares
covered for a given sprayer width and distance covered.