I wanted to share with you a free mobile app that I have found to be quick and easy to use when calibrating a sprayer. I simply enter the parameters that is requested and select the method that you want the app to calculate. I usually request the app to figure volume/area. After, I collect the water for 60 seconds, I enter the amount collected in the input box and tap ‘Calculate’. The app then provides me with the amount that I am spraying per acre, ex: 20 gallons/acre. Of course, then you can adjust the figures in the input boxes (ex: speed, etc..) to obtain the desired amount/acre. Please click on the link below to access the free download. I hope this will be useful to you.