How to Calibrate Your One Gallon Sprayer in a Few Simple Steps

Calibrating your sprayer is essential for effective pest control, ensuring that you're applying the right amount of product over the correct area. This guide will walk you through a simple calibration process to determine how much water you use per acre. Knowing this rate is key to reading labels and mixing the right amount of pesticide product per gallon of water. 

Step 1: Measure Your Calibration Area

Measure a square that is 18.5 feet on each side. Mark this area clearly so you can walk and spray accurately. Find a stopwatch or use your phone to time yourself for the following step.

Step 2: Fill Your Sprayer with Water & Spray

Spray the marked area with water in the same manner that you normally spray. Make sure not to overlap, stay consistent in your walking speed and wand movement. Be sure to record the time needed to spray the marked area. 

Step 3: Re-Fill and Spray Again

Re-fill your sprayer with water and find a bucket or collection vessel. Spray into the bucket for the amount of time recorded in step two. Measure the amount of water in your collection vessel in liquid ounces. 

The collection amount (in ounces) is equal to the spray volume of your sprayer in gallons per acre. 

For example: 

When calibrating a one gallon pump sprayer, I sprayed the marked area in 30 seconds. Spraying for 30 seconds into a bucket, I collected 12 ounces of water. My pump sprayer is applying 12 gallons per acre. 

To determine how much product to mix for one gallon, I consult the product label for the application or use rate. The product I'm using states a 32 ounce per acre use rate. 

My 1 gallon sprayer is calibrated to 12 gallons per acre. The product use rate is 32 ounces per acre. We divide the use rate by the sprayer calibration to determine how much product to add to each gallon of water.  32 / 12 =  2.6 ounces per gallon of water.