Calibrating Your Field Calibrating Your Field SprayerSprayer

Montana State UniversityMontana State University

Pesticide Safety Education ProgramPesticide Safety Education Program

Proper Calibration OffersProper Calibration Offers

Better Pest Control

Environmental and human safety

Effective use of time

Inadequate control = more treatments

Calibrating your SprayersCalibrating your Sprayers

You need to spray 1 pint / Acre of You need to spray 1 pint / Acre of Insecticide.Insecticide.– HOW?HOW?– Cannot just spread 1 pint over an acre without Cannot just spread 1 pint over an acre without

a carrier can you?a carrier can you?

How much to dilute?How much to dilute?

Its easier to spread 20 gallons of water (with 1 pint added) over 1 acre than it is to spread 1 pint by itself.

The goal…….

Find out how many gallons it takes your sprayer to cover one acre

Clean your SprayerClean your Sprayer

Toxic spray equipmentToxic spray equipment– Clean with ammonia and water (2 quarts per Clean with ammonia and water (2 quarts per

25 gallons)25 gallons)– Rinse with waterRinse with water

Replace nozzles, and filtersReplace nozzles, and filters

Determine GPADetermine GPA(4 tools/methods)(4 tools/methods)

Backpack Sprayer– 128th acre method– Long hand method

Boom Sprayer– Calibration Strip Method (Preset Distance)– 5940 Method

Backpack Sprayer Backpack Sprayer (GPA) 128 (GPA) 128thth Acre Method Acre Method

Use water when calibratingUse water when calibrating

Use same nozzles and filters as when sprayingUse same nozzles and filters as when spraying

Measure an 18 ½ by 18 ½ ft area.Measure an 18 ½ by 18 ½ ft area.

Spray area with water and time how long it takesSpray area with water and time how long it takes– Constant speed and constant pressureConstant speed and constant pressure

Spray water into a container for same amount of Spray water into a container for same amount of time.time.

Ounces = Gallons Per Acre AppliedOunces = Gallons Per Acre Applied

Sample ScenarioSample ScenarioUsing 128Using 128thth Acre Scenario Acre Scenario

Takes 10 seconds to spray 128Takes 10 seconds to spray 128thth Acre Acre

In 10 seconds you spray 10 ounces.In 10 seconds you spray 10 ounces.

What is the GPA output?What is the GPA output?

10 GPA

Long Hand ScenarioLong Hand ScenarioGPA for Backpack SprayerGPA for Backpack Sprayer

1 - If you have a different sized section that 1 - If you have a different sized section that you sprayyou spray

2 - Measure out known area sq ft / 43,5602 - Measure out known area sq ft / 43,5603 - Spray known area and time yourself3 - Spray known area and time yourself4 - Spray into bucket for same length of time4 - Spray into bucket for same length of time5 - Measure amount sprayed and convert to 5 - Measure amount sprayed and convert to

gallonsgallons6 - Multiply number found in step #5 times 6 - Multiply number found in step #5 times

the number found in step #2.the number found in step #2.

Sample ScenarioSample ScenarioLong Hand ScenarioLong Hand Scenario

Known area is 66 x 66’ (4,356 sq. ft)Known area is 66 x 66’ (4,356 sq. ft)

43,560 / 4,356 = 1043,560 / 4,356 = 10

It took you 2 minutes to spray areaIt took you 2 minutes to spray area

Collect 4 gallons in 2 minutesCollect 4 gallons in 2 minutes

4 gallons * 10 = 40 gallons per acre4 gallons * 10 = 40 gallons per acre

Boom SprayersBoom Sprayers

No matter what method of calibration is used, you need to….

check nozzle spacing

check output across the boom.

Check nozzle spacing and heightCheck nozzle spacing and height

Boom Level or Nozzle Angle Boom Level or Nozzle Angle CorrectCorrect

Worn Spray TipsWorn Spray Tips

Verify that all nozzles are equalVerify that all nozzles are equal

Nozzle OutputNozzle Output

Check nozzle output for 1 minute and get Check nozzle output for 1 minute and get averageaverage

If each nozzles output is not greater or If each nozzles output is not greater or less than 5% off of average, all is well.less than 5% off of average, all is well.

How?How?

5% error level5% error level

To find 5%Find your average…48 ozMove the decimal place one space to the left. 48. = 4.8 This is a 10% errorDivide by 2 = 2.4. This is 5% errorNow add 2.4 to 48 for +5%Subtract 2.4 from 48 for 5% Error range = 45.6 and 50.4Any nozzle output between 45.6 and 50.4 is OK!

GPA for Boom Sprayer cont..GPA for Boom Sprayer cont..

Nozzle output is same.Nozzle output is same.

18” = 227’ course length18” = 227’ course length

20” = 204’ course length20” = 204’ course length

30” = 136’ course length30” = 136’ course length

40” = 102’ course length40” = 102’ course lengthOr 340 / spacing in feetOr 340 / spacing in feet

Drive course in gear and rpm you will use Drive course in gear and rpm you will use when spraying and time yourselfwhen spraying and time yourself

GPA for Boom Sprayer cont..GPA for Boom Sprayer cont..

Conduct 2 or 3 times and get averageConduct 2 or 3 times and get average

Collect liquid from 1 nozzle for this amount Collect liquid from 1 nozzle for this amount of timeof time

Ounces of liquid collected = GPAOunces of liquid collected = GPA

or GPA for Boom Sprayer can be or GPA for Boom Sprayer can be calculated bycalculated by

Gallons applied per strip= GPA

Test strip in Acres

Sample Scenario Boom SprayerSample Scenario Boom Sprayer

18” wide nozzles, 6 nozzles18” wide nozzles, 6 nozzlesWhat to do?What to do?Travel 227’ and timeTravel 227’ and time30 seconds30 secondsMeasure amount delivered in that 30 Measure amount delivered in that 30 secondsseconds15 ounces in 30 seconds15 ounces in 30 seconds15 GPA15 GPA

How much pesticide to add to the How much pesticide to add to the tanktank

Determine how many acres that can be Determine how many acres that can be sprayed with a given GPA.sprayed with a given GPA.

Volume in Tank / GPA = AcresVolume in Tank / GPA = Acres

300 GALLONS / 30 GPA = 10 acres300 GALLONS / 30 GPA = 10 acres

How much chemical do you need?How much chemical do you need?

2 pints / Acre2 pints / Acre

You will be spraying 10 acresYou will be spraying 10 acres

10 pints of product10 pints of product

5940 method5940 method

GPA = GPM X MPH X W / 5940GPA = Gallons Per AcreGPM = Gallons per Minute collected from a single nozzle (Make sure all nozzle are within a 5% range.)5940 is a constantMPH = Field SpeedW = 1) width between nozzles or2) width of a broadjetswath in inches.

What about field speed?What about field speed?

MPH = GPM * 5940 / GPA * WMPH = GPM * 5940 / GPA * W

Sample ScenarioSample Scenario5940 find speed needed5940 find speed needed

1 nozzle / minute output = 0.2 gallons1 nozzle / minute output = 0.2 gallons

GPA needed is 20 GPAGPA needed is 20 GPA

Width of nozzles is 12”Width of nozzles is 12”

MPH = GPM * 5940 / GPA * WMPH = GPM * 5940 / GPA * W

= 0.2 * 5940 / 20 * 12= 0.2 * 5940 / 20 * 12

= 4.95 mph = 4.95 mph

GPA is given or required!Need GPM for each nozzle!

Then you can purchase appropriate Then you can purchase appropriate nozzles in GPMnozzles in GPM

Rearrange formula once againRearrange formula once again

GPM = GPA * W * MPH / 5940GPM = GPA * W * MPH / 5940

GPM = 20 GPA * 30” * 5mph / 5940GPM = 20 GPA * 30” * 5mph / 5940

0.505 or 0.5 GPM nozzles needed0.505 or 0.5 GPM nozzles needed

Sample QuestionsSample Questions

You have an output of 20 GPA You have an output of 20 GPA

You need to spray 300 acresYou need to spray 300 acres

#1 - How much volume will you need?#1 - How much volume will you need?

6000 gallons6000 gallons

You need to apply 2 oz / acre of Warrior 1E.You need to apply 2 oz / acre of Warrior 1E.

#2 - How much do you put in tank?#2 - How much do you put in tank?

600 oz of Warrior600 oz of Warrior

Questions ContinuedQuestions Continued

You are calibrating your hand sprayer and it took You are calibrating your hand sprayer and it took you 15 seconds to spray 1 18 ½ by 18 ½ ft area.you 15 seconds to spray 1 18 ½ by 18 ½ ft area.

#3 – What is your GPA?#3 – What is your GPA?15 GPA15 GPA

With this 5 gallon backpack sprayer, you intend to With this 5 gallon backpack sprayer, you intend to apply 1 oz / acre of product. apply 1 oz / acre of product.

#4 - How much do you place in your backpack #4 - How much do you place in your backpack tank?tank?

Can only treat 1/3 acre at a 15 GPA rate, so 1/3 Can only treat 1/3 acre at a 15 GPA rate, so 1/3 rate or 1/3 ozrate or 1/3 oz

QuestionsQuestions

5940 example5940 example

You have checked all your nozzles and the average is 64 ounces per minute (OPM). All nozzles are within 5% of this average.64 OPM = 0.5 GPM (64 ounces ÷128 oz./gallon)Your field speed is 5 MPHYour nozzles are spaced 20”apartGPA = GPM X 5940 = 0.5 GPM x 5940= 2970MPH X W5 MPH x 20 100GPA = 29.70 or 30 GPA