SPRAYER CALIBRATION Nov. 1998

OBJECTIVE Determine the volume or weight that application equipment will apply to a known area under a given set of conditions.

VOLUME OF PESTICIDE SOLUTION APPLIED DEPENDS UPON: NOZZLES PRESSURE SPEED Spacing of Nozzles Viscosity of liquid WHY CALIBRATE??

1984 Colorado Spray Check Program

TeeJet nozzle examples

NOZZLE TIP DESIGNATIONS SPRAYING SYSTEMS CO. HSS8002E HSS 80 02 E HSS = HARDENED STAINLESS STEEL 80 = 80 DEGREE SPRAY ANGLE 02 = 0.2 GALLON PER MINUTE AT 40 PSI E = EVEN FLAT FAN PATTERN FOR BAND APPLICATION

HOW TO CHOOSE THE RIGHT NOZZLE SIZE GPM = GPA x MPH x Nozzle spacing in inches 5940 GPM = Gallons per minute per nozzle GPA = Gallons per acre MPH = Miles per hour

EXAMPLE GPA = 30 MPH = 4 Nozzle spacing = 20 GPM = 30 GPA x 4 MPH x 20 in 5940 GPM = 0.40

Find nozzle capacity in GPM in manufacture's catalog. Desired spraying pressure = 40 psi Using Spraying Systems catalog an 8004 nozzle would work the best.

TeeJet Standard Flat Spray Tips GPA - 20 inch spacing

HOW TO CHANGE SPRAYER OUTPUT NOZZLES Best for large changes in output

HOW TO CHANGE SPRAYER OUTPUT Pressure Only feasible within a limited pressure range Pressure must be increased by a factor of 4 in order to double the flow 10 GPA at 20 PSI 20 GPA at 80 PSI

HOW TO CHANGE SPRAYER OUTPUT SPEED Only feasible within a limited range of speeds Double ground speed will decrease output by 50% 1/2 ground speed will increase output by 50%

MAXIMIZING SPRAYER PERFORMANCE

MAXIMIZING SPRAYER PERFORMANCE BOOM HEIGHT Rule-of-thumb when using 80 degree tips Set the boom above the target by whatever the distance is between nozzles If nozzle spacing is 20" then set boom 20" above target

MAXIMIZING SPRAYER PERFORMANCE NOZZLES Nozzle types Flat fan is best for broadcast application of herbicides Flat fan Even fan

MAXIMIZING SPRAYER PERFORMANCE

MAXIMIZING SPRAYER PERFORMANCE

MAXIMIZING SPRAYER PERFORMANCE

MAXIMIZING SPRAYER PERFORMANCE Nozzle placement Need to be placed for proper overlap. Flat fan nozzles should overlap 30%.

MAXIMIZING SPRAYER PERFORMANCE Nozzle uniformity Nozzle types and orifice sizes must be the same across the boom

MAXIMIZING SPRAYER PERFORMANCE Nozzle orientation Directed straight down toward the ground and angled 5 to 10 degrees from parallel to the boom to prevent collision of spray droplets from adjacent patterns

MAXIMIZING SPRAYER PERFORMANCE Nozzle materials Stainless steel, brass and plastic are the most common. Stainless steel is probably the best choice

RELATIVE NOZZLE WEAR

MAXIMIZING SPRAYER PERFORMANCE Screens and filters Use appropriate screens and filters 0.2 GPM or more use 50 mesh Less than 0.2 GPM use 100 mesh

CALIBRATION OF SPRAYERS Sprayer calibration consists of three major steps: Ensure a uniform discharge from each nozzle tip Document the sprayer output in GPA Determine the amount of pesticide to add to the spray tank

CALIBRATION OF SPRAYERS Items needed for calibration Measuring tape Stop watch Collection tube Flags or markers MEASURE NOZZLE OUTPUT UNDER FIELD CONDITIONS

CALIBRATION OF SPRAYERS Ensuring uniform flow from all nozzles Determine best operating speed to suit field conditions. Select proper nozzle. Make sure nozzles deliver in desired rate range. Remove and clean all nozzle tips and screens.

CALIBRATION OF SPRAYERS Use clean water and flush sprayer system. Replace all screens and tips. Make sure all nozzles are the same. Check flow from each nozzle. Do this daily. Adjust pressure.

Need to replace any nozzle that sprays less than 20 - 1 = 19 oz. Allowing a + or - 5% variation from a new nozzle which of the following 8002 nozzles should be replaced? Nozzle Flow Rate (oz/min at 40 psi) 1 20 (new nozzle) 2 20.5 3 20.1 4 22 5 19.6 6 20 7 18 8 20.1 9 20.4 10 26.1 5% of 20 is 20 x 0.05 = 1 oz Need to replace any nozzle that sprays less than 20 - 1 = 19 oz. Need to replace any nozzle that sprays more than 20 + 1 = 21 oz. Replace nozzles 4, 7 and 10.

STEP 2. DETERMINE SPRAYER OUTPUT IN GALLONS PER ACRE 1. Field acres vs. treated acres (band) a) Field acres = Crop acres b) Treated acres = amount of land sprayed When banding only a portion of the total crop receives the spray. Calibration is based on the actual treated acres.

2. Gallons per acre applied depends on: 1) orifice size of nozzle tip 2) pressure of liquid at the tip 3) speed nozzle tip is moved across the field 4) the viscosity of the liquid being sprayed

THE REFILL METHOD OF CALIBRATION Broadcast Application 1. Fill spray tank with water 2. Adjust pressure within recommended range for nozzles used. 3. Select easily maintained speed that fits field conditions. 4. Spray a measured area. Need to know sprayed swath width (ssw) not boom length.

ssw = noz spacing (ft) x # of noz Example: A boom has 18 nozzles spaced 20 in. apart. ssw = (20 / 12) x 18 = 30 ft Measure off an area to equal 1/10 of an acre. 30 ft x X ft = 43,560 ft/a / 10 X = 4356 / 30 = 145.2 ft Therefore, measure off an area 30 ft by 145.2 ft and this will = 1/10 acre.

5. Return to filling point. 6. Measure amount of water to refill tank. 7. Calculate spray rate with this formula: gpa = gallons sprayed x 43,560 ft2/a swath width x swath length (ft)

Example: A field sprayer with a 30 ft spray swath is sprayed for a distance of 145.2 ft. 4 gallons of water are needed to refill the tank. What is the spray rate? gpa = 4 gal sprayed x 43,560 / 30 x 145.2 = 40 gpa

Band Application 1. Fill spray tank with water 2. Adjust pressure 3. Select speed 4. Measure band width (ft) and multiply by number of bands treated at one time

5. Spray a measured distance in field 6. Return to filling point 7. Measure amount of water to refill tank 8. Calculate spray rate on the band with this formula: gpa = gallons used x 43,560 ft2/a treated width x distance (ft)

A 100 gallon tank can treat 100 / 18.2 = 5.5 acres of bands. Example: A 6-row planter sprays a 12 inch band centered over 36 inch rows. It is sprayed for 300 ft and uses 0.75 gallon of water. What is the spray rate? treated width = 12 x 6 / 12 = 6 ft gpa = 0.75 gal x 43,560 ft2 / 6 ft x 300 ft = 18.2 gpa A 100 gallon tank can treat 100 / 18.2 = 5.5 acres of bands.

However, actual field coverage is equal to: FAT = TAT x ROW / BAND FAT = Field acres/tank TAT = Treated acres/tank ROW = Row spacing (in) BAND= Band width (in) FAT = 5.5 x 36 / 12 = 16.5 acres

STEP 3. Adding the proper amount of pesticide to the tank 1. Divide the capacity of the tank by the gallons applied per treated acre to find the treated acres per tank of spray. 2. To determine how much chemical to add to the tank, multiply the recommended formulated rate per acre by the number of treated acres the tank will cover.

3. Field acres represent the normal reference to field size 3. Field acres represent the normal reference to field size. In broadcast spraying field acres/tank and treated acres/tank are the same. When banding, treated acres/tank will always be less than field acres per tank. BROADCAST: FAT = TAT BAND: FAT = TAT x ROW BAND Where: FAT = Field acres/tank TAT = Treated acres/tank ROW = Row spacing, inches BAND= Band width, inches

EXAMPLE: 200 gallon tank, 10 gallon/acre, 36 inch row, 12 inch band, 2 EXAMPLE: 200 gallon tank, 10 gallon/acre, 36 inch row, 12 inch band, 2.5 lbs/acre of AAtrex 80W. Step 1. 200 gal / 10 gpa = 20 TAT Step 2. 2.5 lb/a x 20 TAT = 50 lb/Tank Step 3. FAT = 20 x 36 / 12 = 60 FAT

EXAMPLE: 300 gallon tank, 40 gallon/acre, 0.5 qt/acre of Banvel. Step 1. 300 gal / 40 gpa = 7.5 TAT Step 2. 0.5 qt/a x 7.5 TAT = 3.75 qt/Tank WHAT IF YOU ONLY WANT TO TREAT 5.2 ACRES? 5.2 a x 40 gpa = 208 gallons 5.2 a x 0.5 qt = 2.6 qt

WHAT IF YOU HAVE 35 GALLONS LEFT IN THE SPRAY TANK AND YOU WANT TO TREAT 4 ACRES? 40 gal will cover 1 acre therefore, 35 gal / 40 gpa = 0.875 acres 4 a - 0.875 a = 3.125 acres 3.125 a x 40 gpa = 125 gallons of water 3.125 a x 0.5 qt = 1.56 qt or 50 oz of Banvel

WHAT IF PESTICIDE RATES ARE LISTED IN TERMS OF POUNDS OF ACTIVE INGREDIENT PER ACRE? Example: You are told to apply 2 lb ai/a of 2,4-D. 2,4-D has 4 lb ai/gal. How many quarts of 2,4-D will you need to apply per acre? chem needed = rate (lb ai/a) / chem conc. 2 lb ai / 4 lb ai = 0.5 gal or 0.5 x 4 = 2 qt/a 2,4-D

Example: You need to apply 0. 5 lb ai/a of an 80% WP Example: You need to apply 0.5 lb ai/a of an 80% WP. How many pounds of product will you need to apply per acre? chem needed = rate (lb ai/a) / chem conc. 0.5 lb ai / 0.80 ai = 0.625 lb/a

1/128 Method Of Calibration Calibrating Hand Sprayers And High Pressure Hand Guns Because a gallon = 128 ounces and the area to be sprayed is 1/128 of an acre, ounces collected = gallons per acre. Calibration is knowing how much spray solution is going on a known area. The one one hundred twenty eighth method is probably the easiest method of calibration to understand. There are other methods that work just as well and if you are comfortable with them by all means use them. This method works because you are putting one ounce on 1/128 of an acre. This is the same as putting one gallon on one acre. However, it isn’t usually practical to spray an entire acre with small hand held equipment. We use 1/128 of an acre because it is a small area and application equipment can quickly and accurately be calibrated. When you collect the output in ounces it equals gallons per acre.

STEP 1 Measure out an area equal to 1/128th of an acre. Approximately 340 sq. ft. or an area 18.5 by 18.5 ft. 18.5 ft 18.5 ft

STEP 1 Measure out an area equal to 1/128th of an acre. Approximately 340 sq. ft. or an area 10 by 34 ft. 10 ft 34 ft

STEP 1 Measure out an area equal to 1/128th of an acre. Approximately 340 sq. ft. or an area 1.5 by 228 ft. 1.5 ft 228 ft

STEP 2 Measure the time it takes to spray the measured area. Repeat several times and take the average time.

STEP 3 Spray into a container for the same amount of time it took to spray the measured area. Measure the water collected, in ounces. The amount collected in ounces equals gallons per acre.

EXAMPLE Step 1. Measure area. 18.5 by 18.5 ft = 340 sq ft HAND SPRAYER Step 1. Measure area. 18.5 by 18.5 ft = 340 sq ft Step 2. Time to spray = 51 seconds Step 3. Amount collected = 40 ounces Therefore; 40 ounces = 40 GPA

DETERMINING HOW MUCH PESTICIDE TO ADD TO THE SPRAY MIXTURE Recommendation is to apply 1 quart of 2,4-D per acre

The sprayer is applying 40 gallons per acre The sprayer is applying 40 gallons per acre. Therefore; you will need to add 1 quart of 2,4-D to each 40 gallons of water. Your sprayer only holds 1 gallon of spray mixture. So how much pesticide will you need to add to the gallon of water?

1 quart or 32 ounces divided by 40 gallons means that each gallon of water contains 0.8 ounces of 2,4-D 1 fluid ounce = 2 tablespoons. Therefore; you will need ~ 2 tablespoons of 2,4-D per gallon of water.

1 fluid ounce = 30 (cc) or (ml) 1 fluid ounce = 30 (cc) or (ml). Therefore; if measuring in cc you would need 0.8 ounces X 30 cc/ounce = 24 cc per gallon of water. A plastic syringe is an easy and accurate way to measure liquid pesticides.

How large of an area will 1 gallon spray. There are 43,560 ft2/acre How large of an area will 1 gallon spray? There are 43,560 ft2/acre. If 40 gallons will spray one acre then one gallon will spray an area 1/40 that size. 43,560 ft2 40 = 1089 ft2

1/128 Method Of Calibration MULTIPLE NOZZLE BOOM-TYPE SPRAYERS This method of sprayer calibration gives sprayer output in gallons per acre when nozzle discharge is measured in ounces over a course length that = 1/128th of an acre or 340 ft2 The 1/128 method also works for large self propelled spray equipment.

STEP 1 Adjust the sprayer pressure and check for uniformity. Operate the sprayer for 1 minute and measure spray from each nozzle. Clean or replace any nozzle that delivers + or - 5% than the output from a new nozzle in good condition.

STEP 2 Measure the spray band width or nozzle spacing in inches on the boom to determine the course length. The area to be sprayed must equal 1/128th of an acre or 340 ft2 If the nozzle spacing = 20" then the distance to travel would be 204 ft.

20" (1.67 ft) X 204 ft = 340 ft2 204 ft 1.67 ft 340 ft2 or 1/128 of an acre

STEP 3 Catch the spray from ONE nozzle while operating the sprayer under field conditions or for the time required to travel the needed distance at a desired speed.

STEP 4 Measure the spray collected in ounces. The number of ounces collected is the same as the number of gallons per acre.

EXAMPLE You have a sprayer that has 15 nozzles on a 30 inch spacing. How would you calibrate it using the 1/128th method?

STEP 1 Make sure sprayer is adjusted properly and nozzles are in good working order.

STEP 2 Measure nozzle spacing in inches on the boom to determine the course length. Using the formula: 4084 / 30 inches = 136 feet Or from Table 1. W = 30 inches and D = 136 feet

Table 1. Distance (D) to travel and seconds required for selected speeds when nozzle coverage is (W) inches. W (in) D (ft) 2 mph 3 mph 20 204 70 seconds 46 seconds 24 170 58 39 26 157 54 36 28 146 50 33 30 136 46 31

STEP 3 Time how long it takes to travel the 136 ft at a desired speed. Travel this distance several times and get an average time. Perhaps it takes an average of 31 seconds to travel the 136 feet.

STEP 4 Collect the spray from ONE nozzle in a container for 31 seconds. Measure the water collected in ounces. The amount collected in ounces equals gallons per acre. If in 31 seconds you collected 20 ounces your sprayer output would be 20 gallons per acre.

DETERMINING HOW MUCH PESTICIDE TO ADD TO THE SPRAY MIXTURE The recommendation from the label is to apply 1 quart of 2,4-D per acre.

The sprayer is applying 20 gallons per acre. Therefore; you will need to add 1 quart of 2,4-D to each 20 gallons of water.

Your sprayer holds 200 gallons Your sprayer holds 200 gallons. So how much pesticide will you need to add to the 200 gallon spray tank? 200 gallons divided by 1 qt 2,4-D per 20 gallons water = 10 quarts of 2,4-D per tank

How large an area can be sprayed by your 200 gallon tank? 200 gallons divided by 20 gallons per acre = 10 acres

CALIBRATING GRANULAR APPLICATORS

CALIBRATING GRANULAR APPLICATORS 1. Adjust orifice and fill hopper. 2. Operate the unit in the field to be treated and collect the granules as the unit is operating. 3. Weigh the amount of chemical delivered.

4. Calculate the area treated. band width x number of rows x length or row spacing x number of rows x length or swath width x length 5. lb of granules/a = [43,560 x lbs of granules collected] divided by [the area of the measured course in ft2]

6. The above steps may have to be repeated until the desired amount is delivered. Example: A granular applicator treats a swath width of 20 ft and is driven over a distance of 217.8 ft. The unit delivers 0.7 lb. What amount of granules are being applied per acre? 43,560 x 0.7 / 4356 = 7 lb/a You want the unit to deliver 100 lbs of product per acre. What needs to be done?

Unit should deliver: [100 lbs x 4356 ft2] / 43,560 ft2 = 10 lbs in the measured course. Adjust the orifice until 10 lbs are collected per 4356 ft2.

FACTORS AFFECTING GRANULAR APPLICATORS 1. Exposed area of the metering orifice 2. Speed of the agitator 3. Ground speed of the applicator 4. Nature and size of the granules 5. Roughness of the field 6. Humidity and temperature When any of the above factors change the applicator should be recalibrated.

SOLUTIONS AS PERCENT OR PPM

Percent concentration by weight: SOLUTIONS AS PERCENT OR PPM Percent concentration by weight: lbs to use = [% by wt x gal final mix x 8.34] divided by [% strength of chem to be used] Example: How much WP containing 40% ai should be added to a 250 gallon tank if the recommended treatment is 0.25% by weight? [0.0025 x 250 x 8.34]/0.4 = 13 lbs

Percent concentration by volume: gal to use = % by vol x gal final mix Example: When using Ally it is suggested you add a surfactant at 0.25% by volume. How much surfactant should be added to a 300 gallon spray solution? 0.0025 x 300 = 0.75 gallons or 3 quarts

Parts per million (ppm): Wettable Powder (dry material) lbs to use = [ppm desired x gal final mix x 8.34] divided by [1 million x % strength of chem used] Example: How much WP containing 40% ai should be added to a 100 gallon tank if the recommended treatment is 1200 ppm? 1200 x 100 x 8.34 / 1 mil x 0.4 = 2.5 lbs

Parts per million: Liquid gal to use = [ppm desired x gal final mix x 8.34] divided by [1 million x lbs ai/gal] Example: How much liquid EC containing 0.625 lbs of ai/gal should be added to a 100 gallon tank if the recommended treatment calls for 300 ppm ai of a liquid chemical? 300 x 100 x 8.34 / 1 mil x 0.625 = 0.4 gallons

SUMMARY Find a calibration method you understand and use it every time.

Exams with calibration problems on them Ag pest control-weed & insects (901 A & B) Chemigation (901 F) Forest pest control (902) Ornamental & turf-weeds (903 A) Aquatic pest control (905) Right-of-way pest control (906) Industrial, institutional, structural & health related pest control (907) Regulatory pest control (909) Demonstration & research pest control (910) Aerial (912)