Enclosed between the fabric and the PVC is the chemical delivery line with micro sprays spaced every 100 mm. Two thin felt strips spaced 50 mm apart are stitched inside the bottom of the blanket across the full width to help distribute liquid evenly. Chemical delivery Compressed air is used on the experimental unit to deliver liquid to the blanket by pressurising a 10 L stainless steel chemical tank. Alternative delivery systems which could be used on blanket wipers include gravity feed, compressed air or pump supply. The correct delivery system will depend on the size of the unit and available funds.
Flow rate is controlled by adjusting the air pressure and is switched on and off by a solenoid.
A dwell meter mounted on the motorbike or inside the vehicle cab determines the interval the solenoid will open and the number of intervals open in a given time. Altering the settings on the dwell meter regulates the flow rate to match the density of the weed infestation, allowing the blanket to be saturated but not dripping continuously. The experimental boom has an adjustable spring tensioning system to enable the wiper to be more rigid when treating woody or tall growing weeds such as bracken and Paterson's curse. This feature is optional. Journal of Agriculture - Western Australia, Vol.