Sprayer CalibrationUsing the

K.I.S.S. Method

Craig Runyan, Water Programs CoordinatorExtension Plant Sciences Department

New Mexico State University

Steps to Proper Application

*Know the Pest

*Consider alternative controls

*Know the surface area measurement

*Insure accurate application rate

*Use appropriate PPE

*Carefully calculate & measure tank mix

Sprayer Constants

Four elements of sprayer operation. When any one changes, the equipment MUST be

Recalibrated

-Ground speed

-Spray pressure

-Nozzle orifice size

-Number of nozzles

Getting Started

What You Need -Personal Protective Equipment

-Measuring tape 50 ft or >

-Measuring beaker in fluid ounce graduations

-Stop watch or sweep second hand

-Calculator (for the mathematically challenged)

What You Need to Know

43560

128

Step 1

Determine Effective Spray Width (ESW)

ESW(broadcast) = nozzle spacing x # of nozzles

Example - ESW = 20” x 8 = 160” or 13.3 ft

ESW (banding) = band width x # of nozzlesExample - ESW = 6” x 8 = 48” or 4 ft

Step 2

Measure off a Test Area (TA)

ESW x any convenient lengthExample - 13.3’ x 50’ = 665 sq. ft.

Step 3

Determine the # of Test Areas/Acre

# of sq. ft./Acre = TA/Acre

# of sq. ft./TA

Example 43560 sq. ft./Acre

665 sq. ft./TA = 65.5 TA’s/AcreNote: For application rates per 1000 sq.ft., substitute 43560 with 1000.

Step 4

Determine time required to cover TA

•Operate sprayer with speed and pressure at field operating conditions

•Reach field operating speed before entering the course

•Determine an average of three timed trials

Step 5

Determine sprayer output for Test Area-Use field operating pressure

-Catch individual nozzle output over time required to cover TA

-Measure each nozzle and compare output relative to others

Note: Maximum + 5% nozzle variation

Determine total output/TAAvg. fl. oz./nozzle x # of nozzles = total fl. oz. Example - 6fl. oz./nozzle x 8 nozzles = 48fl. oz./TA

Step 6

•Determine sprayer output/Acre

fl. oz./TA x # of TA’s/Acre = fl.oz./Acre

Example 48fl.oz./TA x 65.5 TA’s/Acre = 3,144fl.oz./Acre

•Convert to Gallons/Acre

fl.oz./Acre

fl.oz./Gallon = Gallons/Acre

Example - 3,144fl.oz./Acre

128fl.oz./Gallon = 24.5Gallons/Acre