Boom Spray Calibration

Boom Width • Sprayer Output • Spray Mixture

Farm Details

Boom Specifications

The width the boom sprays: outer nozzle to outer nozzle, plus one nozzle gap.

Count only the nozzles that are switched on.

Sprayer Setup

Read off the gauge while spraying. Recorded for your reference.

Collect one nozzle into a measuring jug for 60 seconds at working pressure.

Product & Tank

Enter the L/ha you want to apply to check your setup against it.

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Calibration Questions

Boom spray calibration questions

It tells you how many litres of spray your boom puts on each hectare at a given speed, pressure and nozzle set. Once you know that, you can mix the tank so each hectare receives the rate on the product label.

Three things set the volume per hectare: how fast you drive, how much the nozzles deliver, and how wide the boom sprays. Drive faster and each hectare gets less. Raise the nozzle flow and each hectare gets more.

The seconds it takes to cover 50 m at spraying speed, the boom width, the number of working nozzles, and the flow from one nozzle in litres per minute. Time the 50 m in the block you will spray, with the tank at least half full, because soft ground and slope change your speed.

At the start of every season, after fitting new nozzles, and whenever you change gear, engine speed or pressure. Nozzles wear and pass more liquid as they age, so an old calibration usually under-reads what you are applying.

Need Help With Your Spray Programme?

Book a consultation and we will help you calibrate your boom sprayer and set up an effective spray programme for your farm.

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Overview

Fill in every field and press Calculate once. The results bar shows your speed, the litres per hectare your sprayer delivers, and how much product goes into each tank.

Boom Specifications

  • Boom Width: the width your boom actually sprays. Measure from the outer nozzle on one end to the outer nozzle on the other, then add one nozzle gap. A 24-nozzle boom at 0.5 m spacing sprays 12 m.
  • Number of Nozzles: count only the nozzles that are switched on.

Sprayer Setup

  • Seconds to Cover 50 m: mark out 50 m, drive it at spraying speed, and time it. The calculator converts this to km/h and shows it below the field as you type.
  • Pressure: read it off the gauge while spraying. It is recorded for your reference and does not change the calculation.
  • Discharge Rate per Nozzle (L/min): collect water from one nozzle for 60 seconds and measure it in litres. Check a few nozzles across the boom and use the average.

Product & Tank

  • Tank Capacity: your spray tank size in litres.
  • Product Name: for your reference in the results.
  • Product Rate: the label rate. Choose L/ha for liquids or kg/ha for powders and granules.
  • Target Water Volume: optional. Enter the L/ha you want to apply and the results bar shows whether you are on target.
Always follow the product label. The calculator converts the per-hectare rate into the correct amount for your tank based on the actual sprayer output.

Reading the Results

After pressing Calculate, the results bar shows three values:

  • Tractor Speed: your travel speed in km/h.
  • Actual Sprayer Output: what your sprayer delivers at the current settings (L/ha).
  • Product per Tank: how much product to add to your spray tank, with the area one tank covers.

If you entered a target, a green or amber indicator tells you whether your output is close to it. If they are more than 15% apart, change your speed or nozzle size and recalculate.

Tips

  • Recalibrate at the start of each spray season or when changing nozzles.
  • Change speed or nozzle size to adjust your output. Record your working pressure so you can repeat the setup.
  • Spray one full tank and check the area it covered against the calculator.
  • Record your settings so you can repeat them next time.
New to calibration? Read the step-by-step boom sprayer calibration guide. Spraying trees instead? Use the airblast calibration calculator or the knapsack calibration calculator.