Old 12-07-2011, 09:30 AM
grassmasterswilson grassmasterswilson is online now
LawnSite Platinum Member
Join Date: Mar 2007
Location: nc
Posts: 4,254
Actual spray volume vs calibrated spray

Got my z spray calibrated at the factory settings. I've been spraying for a few days an keeping a daily record of my measured lawn measurements and gallons of spray used. What I have calibrated vs what I actually spray is off. I know it will be different when u take overlap or small lawns at slower speeds. Heading to check and clean my nozzles now.

What is an acceptable difference between the two? Trying to get them as close as possible or change my mix to fit. 10%? 20%? Difference?
Posted via Mobile Device
Reply With Quote
Old 12-07-2011, 11:27 AM
Rayholio's Avatar
Rayholio Rayholio is offline
LawnSite Bronze Member
Join Date: Dec 2005
Location: Joplin, Missouri
Posts: 1,462
In my experience, you'll never get the Z very close.... due to variable speed issues.

I think upto 30% is acceptable (although it makes me cringe a bit).. probably - 10% variation is ideal, but hard to achieve.

Here's the trick.. NEVER go over, or under the calibrated speed while the sprayer is putting out product.

Note that the machine moves at a drastically different speed in turns.. and that the boom section on the inside of the turn will apply more product than the outside... It's not a good idea unless the turn is minor, and sweeping.

So.. I achieved pretty good results by simply NOT turning while spraying. Apply in straight lines, and make sure that your 1st passes around the property allow enough room for full acceloration before the spray is engaged.

Anything you can't get while turning should be trimmed with the wand.

Finally.. Calibrate during every fill.. Keep track of how many sq ft since the last fill, and adjust your pressure slightly to compensate.

One last note... be careful with the spray wand. It puts out a hellofalot at the default PSI.. It really needs it's own regulator.

Hope that helps!
-Ray Goepfert
GreenScape Fertilization & Pest Control
Reply With Quote
Old 12-07-2011, 11:43 AM
Ric's Avatar
Ric Ric is offline
LawnSite Fanatic
Join Date: Sep 2001
Location: S W Florida
Posts: 11,996

Factor like what you're spraying will make a big differences in the actuary of your calibration. When I blanket spray for Fire Ants with a Thrin calibration is not as big an issues as Herbicide might be. With the Fire Ant Blanket spray I can actually miss strips and still gain control or better yet prevention. But when dealing with Herbicides 10 % should be acceptable but I want to be in the + or - 5 % range.


it is one thing to do a off label applications. It is total stupidity to post it on the world wide web and expect people to approve.

You can lead a Donkey to water but you can't make the Jackass Drink

My People Skills are Fine. It is my Idiot Tolerance Skills That needs Work.

Reply With Quote
Old 12-07-2011, 08:51 PM
gregory gregory is offline
LawnSite Bronze Member
Join Date: May 2007
Location: southwest florida
Posts: 1,065
i would say i stay within 10% but i spray the same lot everytime since its my house which in a effect gives me great practice. i have got it down to the gallon....
The Internet lets you be anything you wannabe except smart. Your stupidity will always come out.
Reply With Quote
Old 12-07-2011, 09:06 PM
RigglePLC's Avatar
RigglePLC RigglePLC is online now
LawnSite Fanatic
Join Date: Jul 2006
Location: Grand Rapids MI
Posts: 10,969
Within 10 percent is excellent. But variations in lawn size measurment, terrain, going around round flower beds, curves in the borders all cause inaccuracies.
Calibrate on a big square lawn with water. Carefully measuring your speed and swath width. Then you will be good. Try to get it between 100 and 110 percent. You never want to be too low.
Reply With Quote
Old 12-09-2011, 06:53 PM
jad004's Avatar
jad004 jad004 is offline
LawnSite Senior Member
Join Date: Feb 2011
Location: N.E. Arkansas
Posts: 282
I had the same problem with calibration. I always come out just right on large lawns and about 10% over on small lawns. I figured that was probably ok but now I turn my pressure down 5 psi on smaller lawns and come out pretty close on smaller lawns.
Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Layout Style:

Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2016, Jelsoft Enterprises Ltd.
Copyright ©1998 - 2012, LawnSite.comô - Grand View Media
All times are GMT -4. The time now is 02:09 PM.

Page generated in 0.07843 seconds with 8 queries