Filter
Top Products
8
MICRONAIR AU8000 SPRAYER
6. CALIBRATION
As with any mistblower, an AU8000 sprayer must be calibrated before use. This involves
setting the correct output rate of chemical and adjusting the sprayhead to produce the
appropriate droplet size for the chemical and application technique being used.
The following sections describe the calibration of a standard Micronair AU8000 sprayer.
Some details of the procedures may differ if the sprayhead is used with a different model
of mistblower.
6.1. Output Rate of Chemical
The output rate of chemical from the sprayer will be determined by the required application
rate (in litres/hectare) and the area sprayed per minute (in hectares/minute).
The flow of chemical from the atomiser is controlled by the interchangeable restrictor tube
attached to the on/off valve and by the chemical pressure. Chemical is pressurised by air
from the blower fan and by the optional boost pump (if fitted).
The following steps describe the calibration procedure in detail:
1. Establish the average walking speed of the operator. This will depend upon, for
example, the target being sprayed, the evenness or slope of the ground, the amount
of chemical carried and the temperature.
The most accurate means of assessing walking speed is for the operator to spray the
actual crop or target in a 'trial run' with clean water. The speed can then be
calculated from the time to cover a measured distance.
2. Establish the width of the swath of spray on the target. In row crops or orchard
spraying this can often be determined by the number of rows sprayed at a time. In
public health or pest control spraying using a drift technique over open ground the
swath width must be determined by the use of sensitive cards or paper. These
should be placed both horizontally and vertically. The cards should be mounted
downwind of the spray line. The sprayer must be used under typical conditions of
wind and temperature.
When spraying field crops or open areas (e.g. for locust control), the distance
between successive passes of the sprayer should be less than the measured
maximum swath width to ensure adequate overlap of the spray and allow for
variations in the wind and terrain. For the purposes of calibration, the distance
between passes should be regarded as the swath width.