Spot-spray basics.

Multiple nozzle mode If your Optical Spot Spraying system is deliberately running groups of nozzles - several, or whole boom sections, you are in multiple nozzle mode. The rate calculation for consecutive overlapping fan nozzles in groups is based on their nozzle spacing, 25cm, 38cm or 50cm. The nozzle sizing, depending on the spot rates you are chasing will likely be similar compared to your regular applications, if not the same fan angles.

Single nozzle mode If your intention is to go single nozzle spot spraying, you have to go large! In single spot mode, you're giving every nozzle sufficient spray volume to operate in isolation. Single spot nozzle choices are based on 'spray width' or 'footprint' on the ground at a set height. At 70cm nozzle height for example, that is 51cm for a 40° nozzle, 81cm 60°, 117cm 80° and a whopping 2 meters for a 110° nozzle. You'll need BIGGER nozzles!

Dual mode - Cover-Spray plus Spot-Spray This hybrid mode of operation is available on two systems at the moment done in two very different ways. The Weed-It system, in what they call Dual Mode, delivers a conventional overlapping cover spray with a spot-spray boost when required that is delivered through the same nozzle. Both cover and spot functions are managed by a complex combination of pulse width and frequency modulation.

See & Spray operates quite differently using separate A and B nozzles on the ExactApply system. The cover spray happens in the conventional way through nozzle A and the spot application occurs as a separate action through nozzle B.

For a real deep dive into the mysteries of Spot-Spraying, have a read of The Spot-Spray App's Flight School**Technical Information page!**