10
Example: |
|
|
|
|
Speed: |
| 4 Km/Hour |
|
|
Swath Width: |
| 12 m |
|
|
Therefore: |
|
|
|
|
Area treated | = | S x W | 4 x 12 | = 0.08 ha/min |
|
| 600 | 600 |
|
Table 1 shows the coverage of the sprayer for various swath widths and spraying speeds.
4.Calculate the required output from the sprayer in litres/minute to give the correct application rate for the chemical being used.
The output rate of chemical is given by the area sprayed (in hectares) per minute multiplied by the required application rate in litres per hectare.
Example:
| Coverage: | 0.08 ha/min |
|
|
|
| ||||
| Application rate: | 2 litre/ha |
|
|
|
|
| |||
| Output | = | 0.08 x 2 | = 0.16 litre/min |
|
|
| |||
|
|
|
|
|
|
|
|
|
| |
Speed |
|
|
| SWATH WIDTH (METRES) |
|
| ||||
Km/hr | 2 |
| 5 | 10 |
| 15 | 20 | 25 | 30 | 50 |
2 | 0.007 |
| 0.017 | 0.033 |
| 0.050 | 0.067 | 0.083 | 0.100 | 0.167 |
3 | 0.010 |
| 0.025 | 0.050 |
| 0.075 | 0.100 | 0.125 | 0.150 | 0.250 |
4 | 0.013 |
| 0.033 | 0.067 |
| 0.100 | 0.133 | 0.167 | 0.200 | 0.333 |
5 | 0.017 |
| 0.047 | 0.083 |
| 0.125 | 0.167 | 0.208 | 0.250 | 0.416 |
Table 1 – Coverage of Sprayer in Ha/min
5.Select the correct restrictor tube to give the required flow rate. Table 2 gives the typical flow rate for each restrictor tube both with gravity feed and with the optional boost pump operating. These figures are based on measurements with water. Actual flow rates will depend upon the viscosity of the chemical being used. When the boost pump is not used, the flow rate will also be affected by the height of the sprayhead relative to the chemical tank. The rates in Table 2 are measured with the tank half full and the sprayhead level with the engine.
RESTRICTOR | FLOW RATE (LITRES/MINUTE) | |
NUMBER | Without boost pump | With boost pump |
1 | 0.075 | 0.40 |
2 | 0.150 | 0.80 |
3 | 0.300 | 1.60 |
4 | 0.600 |
|
5 | 1.200 |
|