Calibrating and mixing help please!!

Discussion in 'Pesticide & Herbicide Application' started by woodlawnservice, Feb 25, 2012.

  1. Ric

    Ric LawnSite Fanatic
    Messages: 11,969

    Try and get a Tee Jet Catalog, It has all the Height and width spec for their nozzles. From what you are saying I would adjust my height by eye ball then test it on a solid street or surface. That way you can watch the distribution of your spray pattern. If you get even drying on the solid surface you are Good. If not time to adjust. Remember many nozzles are made to Overlap.

    I have marked off 350 ft on my street. Up and back is 7.000 sq ft @ 10 ft wide. Any adjustments etc I make, I retest on the street with straight water.

    I changed the Engine governor to first tweak the speed to a constant 4 MPH. By having a constant speed I have a starting point to design pump and nozzles sizes. I like to over build and use the Pressure Regulator for the final tweaking.

  2. RigglePLC

    RigglePLC LawnSite Fanatic
    Messages: 13,793

    Its not too easy to measure the amount of water missing after 1000 sqft. It best to fill it to the very top or to a distinct level mark on the tank. Spray a convenient square area with water, standard speed, using the swath width you plan to use as your standard swath...(say 8 feet) with what you feel is adequate overlap. Nozzles shoud be about 18 inches high or as the nozzle book recommends. Measure the square feet covered carefully. Refill with a measuring bucket; determine the amount used. Find the gallons per 1000 sqft. Adjust pressure for small corrections.
    Say you covered 7000 sqft and used 5 gallons. You used 5/7ths of a gallon per thousand sqft...that is about .71 gallons per thousand. 60 gallons covers 85,000 sqft.
    Make a fill chart so you can refer to it when filling the tank with your usual product.
  3. fumblefingers

    fumblefingers LawnSite Member
    Messages: 55

    You are right about measuring but I thought I could use my spray wand attachment, take off the end then pump the remaining water into a 5 gal bucket.

    I will then know how much fluid is dispensed in 100 ft.

    for argument sake lets say I dispursed 3.45 gal in 100 ft 10 ft wide. I would then multiply 3.45 X 43.5 =150 Gal per acre. Since I have a 60 gal tank I would need 2.5 tank fills per acre. So I would devide 32 oz(an acres worth of 24D) by 2.5 to get 12.5 oz per tank. This mix would give me the proper concentration.

    Now to change the argument, lets say i reduced the pressure to 8 PSI instead of 15 and remeasured. With a lower PSI I could get less water so would increase OZ per tank of Weedar 64.

    There must be an easier way but I dont know how to use the pump curves and PSI shown in their charts that came with the Pump (Delevan).

    Is this correct or am I getting mixed up. It has been 66 years since I was in 7th grade :rolleyes:
  4. RigglePLC

    RigglePLC LawnSite Fanatic
    Messages: 13,793

    Fumble your calculations are correct. In my opinion, at least.
    However, if you reduced to 8 psi pressure you would have to repeat the test to find the gallons per thousand sqft. The pump output curves are not accurate enough for this type of thing.
    So you are spraying about 17.4 thousand sqft per tank(if you got 3.45 gals per1000 sqft).
    Using a larger area and a whole tank will help to average out any speed changes and give you a better number. Of course you need to measure the sqft covered.
  5. fumblefingers

    fumblefingers LawnSite Member
    Messages: 55

    Riggle, the 3.45 is just a example and not really the output. My object is to make a chart of gal disbursed per 1000 at different PSIG. But there is one other factor that needs to be considered. That is MPH of tractor travel. I guess that would not matter if the MPH of the tractor travels ALWAYS at the same constant speed of the test run, which would be set by the tach on the tractor (say 2200 RPM).

    What is difficult is getting the mix correct because it is difficult to gage a cockamamie measurement of 24D like 10.42 Oz per tank (example).

    Since the girls in the kitchen have forgotten how to measure now they have a microwave and can buy Hungry Man and Lean Quinine, I am not even sure I can find a measuring cup:hammerhead:. or ask them how to do an accurate measurement. Maybe, I can use the 4oz oil bottles I use for my Stil chain saw.

    Since my tank has a 5" fill hole, I think I will get a black sharpie and mark off 5 Gal increments on the tank and pour in water using a 5 gal bucket. Weedar 64 cost me $60 for a jug so don't want to waste any.
  6. fumblefingers

    fumblefingers LawnSite Member
    Messages: 55

    What confuses me about he Tee Jet charts is for example a orange jet at 30 PSI is the chart says 0.13 gal per 1000 sq ft. So if I have 7 orange jets do I multiply the number by 7 to get the gal disbursed or devide by 7.:cry::confused:
  7. fumblefingers

    fumblefingers LawnSite Member
    Messages: 55

    I just remembered I have Lachler spray jets from tractor supply. a orange jet is supposed to output 4.2 gal per acre at 20 psi at 5MPH so multiplying times 7 jets equals 29.4 gal per acre. I wonder if there is any charts on how to calculate MPH? Since I have a Kubota 7610 diesel, maybe I can find a chart at Kubota.
  8. Ric

    Ric LawnSite Fanatic
    Messages: 11,969

    Charts are great for getting you into the Ball Park, But then you must tweak your calibration manually. A 5 PSI change could mean 10 gallon or more an acre difference. Some people like to use Catch cups and time the flow of each nozzle. Then they do the math to find their rate per acre. Catch cups are great for testing the distribution on the boom, but I prefer Spraying a set area and checking the volume used. I park in the same spot I marked my tank when I refill it, that way I get as actuate a reading as possible.

    0.13 gallon per thousand @ 30 PSI is the average rate of that nozzle. If you are spraying side by side with 7 nozzles you are still only applying 0.13 gallon per Thousand but you are doing it 7 times faster by using 7 nozzles.

    Calibration can be easy if you don't over think it and have a little understanding of how a Boom sprayer works. Once you establish your calibration of the Boom sprayer, changing chemical and application rates is simple. You know your sprayer will cover X # Sq Ft and multiply X times the rate per thousand.

    A side Note: My boom sprayer is used only for Insect Control and 99% for Fire Ant control. Because I want a lot of Carrier for Fire Ant Control, I run nozzles in series or double spray every sq ft. My goal is put out at least 3 gallon a thousand and I would love to put out more. Modern sprayers are designed to only do low volume spraying.

  9. fumblefingers

    fumblefingers LawnSite Member
    Messages: 55

    So that would mean devide by 7........right
    BTW the chart was Lachler not TeeJet. I guess U are correct as I would never get MPH to exact but if RPM is always the same I would be right provided I always floored the pedal. My Kubota goes 0 to 10.2 MPH per specs and since it has only 2 speeds I am guessing low gear is 5 MPH. The charts show 3,4,5,6 MPH so the results could be very different unless U do the calibration your way. Fluid dynamics can be confusing.
  10. turfmd101

    turfmd101 LawnSite Bronze Member
    Messages: 1,376

    See if this helps.

    I'm going on the the 10ft by 100ft = 1000sq ft.
    This will probably be a base to go up or down.
    I believe once you have your ground speed and times to cover 1000 sq ft. flow calibration should be easier.

    Your rig moving 1.14 mph will cover 1000 sq ft in 60 sec.
    Your rig moving 2.28 mph will cover 1000 sq ft in 30 sec.
    and so forth.

    Now spray volume.

    assuming all nozzles are the same flow.
    calibrate one nozzle for 20 sec then multiply by 3 to get GPM.
    then multiply by 7 to get full volume per minute.

    so for instance if you are getting .25 gallon in 20 sec = .75 GPM
    multiplied by 7 = 5.25 GPM to high for foliage app.

    So if you were traveling at 1.14 mph you will apply 5.25 GPM per 1000 sq ft.
    If you were traveling at 2.28 mph you will apply 2.63 GPM per 1000 sq ft.

    one mile = 5,280 ft. there are 52.8 100ft sections in one mile.
    dividing this by 60 sec = 88ft per sec.
    60 sec divided by 52.8 = 1.136 or 1.14 mph to travel 100ft.

    I hope this helps you.

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