Calculations, i want to dbl check my #'s

Discussion in 'Pesticide & Herbicide Application' started by bcomstock15, Jul 5, 2011.

  1. bcomstock15

    bcomstock15 LawnSite Member
    Messages: 42

    Hello. I have a Fimco ATV sprayer (atv-25-71) with 7 nozzles (8002s) and a 140" boom ill operate at 40 psi.

    I'm spraying Par III which reccomends 55 mL in 3 L of water/100m^2.

    my machine moves at 1.25 mph(2 kph), 2.5 mph(4kph), or 3.5 mph(5.6kph)

    how many mL per litre will i mix at each speed?

    Thank YOU! :waving:
  2. bcomstock15

    bcomstock15 LawnSite Member
    Messages: 42

    I have calculated about 25 mL per 1 litre water @ 4km per hr (2.5 mph).

    Does that seem like it would reflect what the label requires?
  3. PR Fect

    PR Fect LawnSite Bronze Member
    Messages: 1,076

    You need to know how many litters of water each nozzle sprays in a measured amount of time. Or a least an average amount of spray between the 7 nozzles. Say its an average of .25 liters per minute, per nozzle as an example. Then you need to know the distance in 100m2 that you traveled at those speeds. Say it took you 1 minute to go 1,000m2 at the 2kph speed. Then you can do the math on a measured amount of liquid you put down in a measured area, at a set speed, in a set time.
  4. vencops

    vencops LawnSite Bronze Member
    from NC
    Messages: 1,537

    I have the same rig (ATV-25-71). I'm curious as to what kind of coverage you're getting (no streaking?)....and what height you have your boom set at.

    I'm also curious (from others familiar with this rig) if there aren't better nozzles available.

    What do you have this mounted on?
  5. bcomstock15

    bcomstock15 LawnSite Member
    Messages: 42

    PR Fect: thanks for helping with this, according to my sprayers manual, with these nozzles, the spray rates at 40 psi are 0.2 gpm, and have the following usage over 1000 ft. squared (i prefer metric, but its American made):

    1mph: 1.36 gallons
    2mph: .68 gallons
    3mph: .45 gallons

    Is this the information required?


    I have it mounted on a JD walk behind, its exactly 18" as spec'd in the instructions. don't know about different nozzles.

    Streaking i would imagine applies more to fert apps, i wouldn't see anything like that with herbicide.

    Thanks for the help.
  6. RigglePLC

    RigglePLC LawnSite Fanatic
    Messages: 13,793

    This is hard for me after doing the metric conversions. I found your instructins are about right--at 3.5 mph, my calculations showed you would be applying about 1.04 ounce per 1000 sqft. Perfect.

    Except if you have tough weeds I would go slower at 2.5 mph, thereby applying about 1.45 ounces per 1000 sqft. Why kill some of the weeds? Kill 'em all.
  7. bcomstock15

    bcomstock15 LawnSite Member
    Messages: 42

    Thanks RigglePLC , i prefer to do it on a mL/litre basis at each speed. Is this a bad way to think of things? just seems easier for me to remember.

    2.5 kmh = 25mL/L
  8. CLS LLC

    CLS LLC LawnSite Senior Member
    Messages: 487

    I run the same model and have found the provided nozzles to be worthless. The spray pattern is very narrow and you would have to set your boom height to about 40 inches to get adequate coverage. I use the following nozzles at 20 inch nozzle height and they are a huge improvement. I wouldn't even use this sprayer if I had to use the original nozzles.

    If I were to do it again I would spend the extra money to get air induction nozzles to decrease drift. Like these:

    They are expensive but they are worth it.

    Also to the original poster there is a chart in the fimco manual that gives you very good guidlines if you are using the original nozzles. If I recall though it is OZ and not ML.
  9. RigglePLC

    RigglePLC LawnSite Fanatic
    Messages: 13,793

    you are fine with metric system. Just remember that the faster you go --the less herbicide you are aplying per sq ft or sq meter or whatever units you are using. And don't trust what the manufacturers are saying--you have to calibrate for yourself--and then make a fill chart or spreadsheet for the various conditions and speeds.

    Angle the nozzles back to reduce drift.
    Last edited: Jul 10, 2011
  10. bcomstock15

    bcomstock15 LawnSite Member
    Messages: 42

    Well, I sprayed part of my back yd last week with the 25 ml/L@4 km/hr, and it seems like it must be too weak. It turned some clover brown, but didn't affect the thistles or dandelions much. Should i just try adding another 5ml/L to the mix and try again? probably not haha.

    Based on the information i gave above, can anyone come up with a mL/L @ 1.25 mph(2 kph), 2.5 mph(4kph), or 3.5 mph(5.6kph) ? I know its asking alot, i just want to make sure my numbers are correct before taking the rig on customers property. Thank You.

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