How to Calibrate Your Spreader Sprayer                                                                  Contributed by Guest Blogger: Martin McGuane, owner and operator of McGuanes Landscaping and Tree Service, Enfield CT

There are few things more important in the chemical lawn care business than ensuring that your spreader sprayer is calibrated. Calibration is the process used to make sure that the spray equipment properly disperses the pesticide at the proper rate.

Why Calibrate Your Spreader Sprayer?

Key reasons why calibration is so important include:

• Applying a mixture too heavy wastes material and money.
• Applying a mixture too light will not effectively control your target pests.
• Operating an uncalibrated sprayer is environmentally irresponsible.

A Brief Overview

There are many factors involved in calibrating a sprayer. You could spend weeks learning about calibration. However, our purpose in this blog post is to provide a simple, yet effective and accurate way to ensure you’re delivering the correct amount of solution.

Steps to Calibrate a Spreader Sprayer

Let’s walk through the quick and easy steps to calibrate a spreader sprayer:

• Make sure your screen is clean.
• Set your sprayer to the desired PSI.
• Set your ground speed.
• Measure the width of your sprayer bar. For this example, we will assume the sprayer bar measures 7 feet.
• Determine the amount of feet you will need to spray to get 1,000 square feet of coverage (1000/7 (length of sprayer bar) = 143ft).
• Add a known quantity of water to your sprayer.
• Blanket spray the determined length from above (In this case, 143 feet).
• Once you finish spraying, determine how much water you used.

Determine the Rate

Let’s assume we used 1 gallon on our 1,000 square feet. Let’s also assume that the manufacturer’s recommend rate for your weed killer is 1oz. per 1,000 square feet. Based on this, we know that we will need to mix 1oz. of weed killer per gallon.

Keep an Eye on Your Calibration

Once your sprayer has been calibrated you should confirm the calibration regularly throughout the day. Using the example from the previous paragraph, if we are applying a blanket application to a 10,000 sq. ft. lawn, we should be using 10 gallons of dilute. If not, we need to adjust our mix, our speed or possibly our pressure.

Get More Information

Want to learn more about calibration? Check out Sprayer Depot’s previous blog post, How to Calibrate a Boom Sprayer.