Spraying is about placing the correct dose of product at the right place, at the right time.

Calibration is the process of checking, and adjusting, where necessary, the accuracy of all components that have an impact on the performance of the spray application equipment. It is more than just measuring the individual parameters of speed, flow and width.

When calibrating a sprayer it is important to consider areas of potential error, including:

• speed;

• nozzle pressure;

• flow meters and liquid density;

• tank capacity;

• section widths and nozzle spacing;

• measuring jugs, buckets and scales; and

• tractor speedometer.

Before you calibrate

To minimise risk, prepare your sprayer components before you begin to calibrate:

• complete a spray plan and know how you need to apply each product;

• select appropriate personal protection equipment;

• ensure the sprayer is cleaned internally and externally, including nozzles and filters;

• check, adjust if necessary, and record tyre pressures;

• fit the appropriate nozzles (according to the spray plan);

• record all rate controller settings – flow meter constant, speed constants, boom width/nozzle count per section; and

• ensure oil is at operating temperature where hydrostatic drive sprayers are in use (never calibrate cold).

Tip

A good spray plan provides the basis for the calibration process. An applicator should carefully consider how each product is to to be applied, including: the desired application volume, spraying speed, nozzle type, spray quality and operating pressures.

Find out more

For more information go to Module 5: Spray plans