How much herbicide to put in the tank

Summary

If calibrated, the machine doses 278L/Ha of herbicide mix. This applies only for the treated area, hence if there is 10% weed coverage, only 27,8L will be used per hectare. Nevertheless, the present regulations imply that when selecting the herbicide concentration, one must assume that the whole area is treated, and use 278L/Ha for calculation of the amount of herbicide.

How to calibrate the dosed volume

Preparation

In order to ensure proper calibration, always do it with the correct herbicide in the system, as the herbicide formulation will affect fluid properties, and the final result.

The calibration can be done by going to Settings -> Spraying -> Periodic inspection -> Step 12 and go to liquid distribution section. Note that the pump must be enabled.

To perform the calibration, a patternator tool illustrated below is needed. There are two parts to the tool, the lower part is split into 42 containers, each collecting droplets for the respective droplet generator. This part can detect malfunctions in single droplet generators.

The upper part is measuring the average volume dosed by the entire spray unit, and is used to calibrate the areal dosage. If the machine is calibrated properly, the nominal herbicide mixture application rate is 278 L/Ha, but only within treated areas.

In both cases, there are 3 lines, the middle line is the nominal value, and the upper and lower line are acceptable limits after calibration is complete.

The first part of the test fires 1000 droplets into each of the 42 measurement columns and measures the coefficient of variation. The second part, fires 3000 droplets from each droplet generator, and measures the average for a whole spray module, and is used to calibrate the ejected volume, and hence areal dosage.

Perform calibration

Run Prepare nozzles and wait for it to complete.
Attach the patternator tool
Run Coefficient of variation test and wait for it to complete. The first test criterion is not mandatory to pass when doing calibration only, but if there are any deviations, it is a good indicatior of nozzle malfunction.
Without emptying the collector, run Area dosage test and wait for it to complete. when the tool is on a level surface, the bottom of the fluid surface, should be as close to the middle line as possible, and it must be within the upper and lower limit lines.
If the volume is too high, or too low, press the Droplet calibration, select the deviating spray unit, and move the slider to change the volume. Then redo the test.

Upon completion, the herbicide mix dosage should be within acceptable limits of 278L/Ha.

Example calculation of the amount of herbicide

We have herbicide A, and for our culture, the dosage rate is 2L/Ha. Our tank volume is 50L, hence the amount of herbicide is 0.36L per tank.