Calibration using the Test Calibration using the Test Strip Method (Long Hand)Strip Method (Long Hand)

Cecil TharpCecil Tharp

Pesticide Education ProgramPesticide Education Program

Montana State University ExtensionMontana State University Extension

Calibration Benefits You!Calibration Benefits You!

You will not under apply Maintains the Best Pest Control

Will not over-apply Environmental and human safety risks

No need to re-apply Effective use of time Save $$

Follow Along Using Follow Along Using MSU Reference MaterialsMSU Reference Materials

Use the MontGuide titled Use the MontGuide titled “Calibrating Pesticide “Calibrating Pesticide Application EquipmentApplication Equipment Pre-calibrationPre-calibration Testing NozzlesTesting Nozzles Calibrating OutputCalibrating Output Proper Tank MixingProper Tank Mixing

Suggested Calibration ToolsSuggested Calibration Tools

StopwatchStopwatch Measuring TapeMeasuring Tape Measuring ContainerMeasuring Container Pencil and paperPencil and paper Source of fresh waterSource of fresh water

Goal: To verify the output of your Goal: To verify the output of your sprayer. This depends on:sprayer. This depends on:

SpeedSpeed PressurePressure Type of nozzleType of nozzle

Pre-calibrationPre-calibration

Verify your SpeedVerify your Speed

Make a test strip to verify MPHMake a test strip to verify MPH

Distance (feet) x 60 Distance (feet) x 60 Time (seconds) x 88*Time (seconds) x 88*

It takes 1 minute to travel 88 feetIt takes 1 minute to travel 88 feet

How many mph does that equal?How many mph does that equal?

1 MPH1 MPH

Calibrating your Backpack Sprayer Calibrating your Backpack Sprayer using Long Hand Methodsusing Long Hand Methods

#1 Measure a test strip area and flag#1 Measure a test strip area and flag Area = Length x WidthArea = Length x Width (example: 15 ft by 15 ft area.(example: 15 ft by 15 ft area.225 square feet)225 square feet)

#2 Convert test strip to acres #2 Convert test strip to acres Acres = Area in Square Feet / 43,560Acres = Area in Square Feet / 43,560 (example: 225 / 43,560 ft = (example: 225 / 43,560 ft = 0.00516 acres0.00516 acres

Calibrating your Backpack Sprayer Calibrating your Backpack Sprayer using Long Hand Methodsusing Long Hand Methods

#3 Spray test strip area with water and #3 Spray test strip area with water and time how long it takes (example: 40 time how long it takes (example: 40 seconds)seconds) Take 3 assessmentsTake 3 assessments Constant speed and constant Constant speed and constant

pressurepressure

#4 Collect in a container for#4 Collect in a container for

same amount of time.same amount of time. Example: 40 seconds in 1 Example: 40 seconds in 1

container = .1 gallonscontainer = .1 gallons

Now Determine GPA!Now Determine GPA!

#5 Determine GPA #5 Determine GPA GPA = Gallons Applied in Test Strip / Test Strip AcresGPA = Gallons Applied in Test Strip / Test Strip Acres

Example: 19.38 gallons = .1 gallon / 0.00516 Example: 19.38 gallons = .1 gallon / 0.00516 acresacres

#6 Output = #6 Output = 19.38 Gallons Per Acre19.38 Gallons Per Acre

Sample Scenario – Find GPA for Backpack SprayerSample Scenario – Find GPA for Backpack Sprayer

#1 Measure out an area that is 14 x 14 ft. How #1 Measure out an area that is 14 x 14 ft. How many square feet is that? many square feet is that?

196 square feet196 square feet

#2 How many acres is that? #2 How many acres is that? 196/43,560 = 196/43,560 = 0.004 acre0.004 acre then what? then what?

#3 #3 Spray and timeSpray and time. Sprayed area in 65 seconds. Then what?. Sprayed area in 65 seconds. Then what?

#4 Sprayed into container for 65 seconds #4 Sprayed into container for 65 seconds Get Get 0.2 Gallons0.2 Gallons then what then what

#5 #5 Convert to GPA! GPA = Gallons in Test Strip / Test Strip AcresConvert to GPA! GPA = Gallons in Test Strip / Test Strip Acres

Example: Example: 50 GPA50 GPA = .2 gallon / 0.004 acres = .2 gallon / 0.004 acres

CALIBRATING BOOM CALIBRATING BOOM SPRAYERSSPRAYERS

Find GPA? How?Find GPA? How?

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

Due to problems with wear you must test Due to problems with wear you must test uniformity of nozzles annuallyuniformity of nozzles annually

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 10% off of average, all is well.less than 10% off of average, all is well.

How?How?

10% error level10% error level

To find 10% Find your average…48 oz Move the decimal place one space to the left.

48. = 4.8 This is a 10% error Now add 4.8 to 48 for +10% Subtract 4.8 from 48 for -10% 10% Error range = 43.2 and 52.8 Nozzle outputs between 43.2 and 52.8 is OK!

GPA for Boom Sprayer GPA for Boom Sprayer

1.1. Determine Nozzle Output is the same.Determine Nozzle Output is the same.2.2. Establish Spray Strip DimensionsEstablish Spray Strip Dimensions

-Nozzle spacing (ft) x Test Strip Distance-Nozzle spacing (ft) x Test Strip Distance-Example: Nozzle spacing is 3 ft; test strip is 200 ft-Example: Nozzle spacing is 3 ft; test strip is 200 ft

3.3. Convert to AcresConvert to Acres-Square feet in test strip / 43,560 = Acres-Square feet in test strip / 43,560 = Acres-Example: 600 / 43,560 = -Example: 600 / 43,560 = 0.0137 acres.0.0137 acres.

4.4. Spray the test strip while measuring time.Spray the test strip while measuring time.-Spray in gear and rpm you will use when spraying-Spray in gear and rpm you will use when spraying-Example: 27 seconds to spray the 0.0137 acre test -Example: 27 seconds to spray the 0.0137 acre test

strip.strip.

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

5. Collect and measure liquid from 1 nozzle5. Collect and measure liquid from 1 nozzleexample. collected 1.1 gal from nozzle in 27 seconds.example. collected 1.1 gal from nozzle in 27 seconds.

6. Determine GPA6. Determine GPA-GPA = Gallons Applied to Test Strip / Test Strip Acres-GPA = Gallons Applied to Test Strip / Test Strip Acres

-Example: 1.1 gallon / 0.0137 acres-Example: 1.1 gallon / 0.0137 acres

80.29 GPA80.29 GPA

Fine tune your GPA by adjusting:Fine tune your GPA by adjusting:

SpeedSpeed Slower speed increases outputSlower speed increases output

Pressure Pressure Only slight adjustmentsOnly slight adjustments

Nozzle sizeNozzle size Use 5940 to get you closeUse 5940 to get you close Not meant for fine adjustmentsNot meant for fine adjustments

Nozzle spacing Nozzle spacing Often presetOften preset

Speed effects output!Speed effects output!

Spray Pressure for adjusting GPASpray Pressure for adjusting GPA

Increasing spray pressure raises the flow rateIncreasing spray pressure raises the flow rate You would need to increase pressure by 4 times to You would need to increase pressure by 4 times to

double flow ratedouble flow rate Increasing spray pressure decreases droplet sizeIncreasing spray pressure decreases droplet size

This causes driftThis causes drift Less than 30 psi generally considered low driftLess than 30 psi generally considered low drift

Read your nozzle specifications on pressureRead your nozzle specifications on pressure OnlyOnly small adjustments in pressure are small adjustments in pressure are

recommended for altering output.recommended for altering output.

You know GPA, now how much You know GPA, now how much solution do you need?solution do you need?

Acres * GPA = Volume in TankAcres * GPA = Volume in Tank 10 acres * 30 GPA = 300 Gallons10 acres * 30 GPA = 300 Gallons

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

Acres * product rate = Total Product Acres * product rate = Total Product Product Rate = 2 pints / AcreProduct Rate = 2 pints / Acre You will be spraying 10 acresYou will be spraying 10 acres 20 pints of product20 pints of product

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 of a spray mixture will you need?#1 - How much of a spray mixture 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 product do you put in that same #2 - How much product do you put in that same tank?tank?

600 oz of Warrior600 oz of Warrior

Questions ContinuedQuestions Continued

#3 You have a 2 ft wide nozzle spacing #3 You have a 2 ft wide nozzle spacing and travel 204’ in 25 seconds.and travel 204’ in 25 seconds.

--How many square feet is this strip?How many square feet is this strip?

Length x Width = Length x Width = 408 square feet408 square feet

-How many acres is this strip?-How many acres is this strip?

square feet / 43,560 = square feet / 43,560 = 0.0093 acres0.0093 acres