Hardi MARRO TWIN FORCE 1000 Instruction Book

28 GB 09 01Air TechniqueA Setting of air speed, rules of thumbStep 1: Find the range of air speeds that can controldrift:1.Start with the air setting at zero and keep increasingthe air speed just to the point where you can see thatthe drift cloud is minimised - note minimum setting.2.Then increase the air speed until you see drift again -note maximum setting.3.Now you know the range of air speeds that can beused with minimum drift.Bare ground / low cropThe range of air speeds is usually very small.Taller cropThe taller the crop the wider the range of air speeds thatcan reduce drift.At higher wind speedsMore air is needed on the sprayer and it is advisableto drive more slowly and use minimum boom height(40 cm)/(16 in).NOTE! Too high air speed over bare ground/low cropcan cause reflection of the spray liquid and leave duston the leaves, which can again reduce the effect of theplant protection product.Step 2: Set the optimal air speed within possible therange mentions above.Conditions Air speed recommen-dationsBare ground / low crop: Use maximum airwithin the possi-ble rangeTaller crop: Deeper crop penetra-tion re-quires more air on thesprayer (if you are in doubtcheck with water sensitivepaper).Forward speed: Higher forward speedsrequire more air on thesprayer.Volume rate: Lower volume rates requiremore air assistance toavard drift.B Angling of air and liquid, rules of thumbTo control wind drift the influence of wind speed andwind direction as well as the horizontal air currentaround the boom due to forward speed must be mini-mised. Because it is a sum of two forces with variabledirection and size that we have to counteract for, thefollowing can only be very rough guidelines.NOTE! Often it will be necessary to drive with twodifferent anglings, so the angling is changed whenchanging driving direction after turning at the headland.Wind direction Angle / air speedHead wind: Angle forwardDown wind: Angle back (if the forwardspeed is higher than thewind speed: angle for-ward)Side wind /No wind: Angle vertical or back. Onlyhigh forward speeds mayrequire forward angling.Crop condition Angle / air speedBare ground/low vegetation: Low air speed and angling backwill often be the bestsetting to avoid reflection ofspray liquid.Dense crop: The angling feature is ideal tohelp opening the canopy and improve penetration. Ifyou follow the crop movementas you are varying theangling you will find that at certainsettings the crop will open more forpenetration.If wind speed, wind direction or for some reason forwardspeed changes during spraying the optimum angling islikely to change too. Be aware that with certain combina-tions of air speed and angling you can ìcloseî or flattenthe crop and make penetration impossible - follow thecrop movement intensively especially when setting theair assistance and keep an eye on the crop all throughthe application.NOTE!ï It is most important that the sprayer operator is familiarwith the above rules of thumb before using the TWINsprayerï All volume rates, pressures and air adjustments statedin the following tables are, of course, guiding. Specialconditions regarding climate, crop quality, spraying timeand applied chemical can change the procedure. Thetables are showing practice in northern Europe, andconditions may be very different in other countries. If youwant some local advice you are very welcome to contactthe TWIN application expert at the HARDI importer ordaughter company in your countryï The volume rate can generally be reduced to half ofwhat is applied with a conventional sprayer, but with a