OMAFRA Sprayer Calibration
Table of Contents
- Downloadable Version - Field Sprayer Calibration
- Field Sprayer Calibration
- Hand/Backpack Sprayer Calibration
- Related Links
Download a copy of the new Field Sprayer Calibration Calculator
to use on your personal computer. Created for use with Microsoft
Excel, the calculator performs the following tasks:
- Determines the volume of spray material applied in metric and
imperial units for both banded and broadcast applications.
- Determines which nozzles, if any, need to be cleaned or replaced
based on their output.
The minimum system requirement is Microsoft Excel 97. Download
Microsoft Excel viewer.
Note: When prompted, you must enable macros for the calculator
Scroll down to try the online versions for calibrating Field and
Field Sprayer Calibration
(Determining application rates in litres per hectare)
There are many ways of determining the number of litres of spray
material that are being applied to one hectare of land - or calibrating
1. Measure the time
- Place 2 stakes 50 metres apart in the field
- Select the gear and throttle setting (r.p.m.) at which you plan
- Fill the sprayer half full of water
- Drive the distance between the stakes three times, timing each
pass. Each time, make sure the tractor is at the desired speed
as you pass the first stake. Keep driving at this speed until
you pass the second stake.
- Take the average time of the three passes
2. Measure the average nozzle output
- Park the sprayer with the PTO engaged and the throttle adjusted
to reach the PTO speed set in the test run
- Adjust the pressure regulator to the desired working pressure
with full flow to the boom
- Collect the output from each nozzle for the average length of
time needed to travel the 50 metres in the test run.
- Enter the nozzle outputs into the chart below
- If any nozzle is more than 5 % above or below the average output,
it should be cleaned or replaced
3. Measure the nozzle spacing in metres
4. Use the following formula to determine the sprayer output:
Sprayer Output (L/ha) = (Average Nozzle
output (mL) ÷ Nozzle spacing (m)) x 0.2
5. Calculate the actual area sprayed after each tank of spray solution
- Re-check the actual sprayer calibration after each tank of spray
is applied by dividing the volume sprayed by the actual area sprayed.
The nature of some products may slightly alter the calibration
from that of clean water.
6. Growers who prefer to measure in litres/acre or gallons/acre,
can use the following conversion guide:
- Litres per hectare x 0.4 = Litres per acre
- Litres per hectare x 0.09 = Imperial gallons per acre
- Litres per hectare x 0.11 = U.S. gallons per acre
- Sprayer calibration bottles or kits are available from a number
of suppliers. For further information contact the OMAFRA Agricultural
Information Contact Centre at 1-877-424-1300, or manufacturers
of sprayers, sprayer parts, or herbicides.
- For banded spray applications, measure the
width of the of the spray band (at the soil surface or surface
of the crop canopy) and enter this value into the formula instead
of the "nozzle spacing." Where band spraying the acreage
sprayed is NOT the same as the crop acreage. The herbicide rates
referred to in most herbicide publications and labels refers to
the actual area sprayed unless otherwise stated.
Hand/Backpack Sprayer Calibration
Many people use small hand-held or back
pack sprayers for treating problem areas or spraying areas that
were missed. Calibration of the sprayers is as important as calibrating
your field sprayer.
Instructions For Calibrating The Hand Sprayer
Method 1: Hand Sprayer
Method 2: Hand Sprayer
- Measure out an area that is 100m2.
For example 10m x 10m, or 25m x 4m
- Fill the spray tank with water.
Mark the level on a measuring stick. Pump to the pressure that
will be used during the pesticide application.
- Spray the water over the 100m2 area.
Walk at a steady pace, taking care to apply it as evenly as possible,
just as you would when applying pesticide.
- Measure the amount of water needed to fill the spray tank
to the mark on the measuring stick.
This amount will be the sprayer output per 100m2
If the spray tank is not large enough to cover an area 100 m2,
use the following calibration procedure:
- Measure the amount of water needed to fill the sprayer.
Pump to the pressure you will use during the pesticide application.
- Spray an area as evenly as possible, walking at a steady
Spray until the tank is empty.
- Measure the number of square metres covered
For example: 6m x 10m = 60 m2 or 8m x 3m = 24m2
- Use the recommended amount of pesticide for this number of
square metres each time you fill the tank.
- To convert the application rate of any pesticide to the amount
required for a small area, follow this guide:
- 1 kg per hectare is equal to 10 grams per 100 square metres
- For liquid measure, 100 litres per hectare is equal to 1
litre per 100 square metres.
- One level tablespoon equal 15 mL.