Page 166 - AG 7-2011 Revised 2016

CALIBRATION OF PESTICIDE
APPLICATION EQUIPMENT

(Courtesy of UNIVAR)

I. OBJECT OF CALIBRATION
Apply uniformly, and in the desired areas, the proper amount of active ingredient.
Advantages: proper pest control, and minimum of pollution and cost.

II. PRINCIPLES OF CALIBRATION
A. Be certain of two things:
1. Nozzle output and pattern is the one desired and is uniform where desired.
2. The amount of liquid applied per unit is known, and constant.
B. In order to do this:
1. Pressure at the nozzles must remain constant, and must be at the desired
value when calibrating.
2. Speed, or rate of travel, must be known, remain constant and be at the
desired rate when operating.

III. OUTLINE OF PROCEDURE
A. Use water for calibration.
B. Field operate (with water) adjusting to desired values:
1. Spray patterns - including Pressure.
2. Speed of operation noting both distribution and quantity of water on the
plant and/or soil.
3. Record:
a) pressure
b) speed of travel - either MPH or gear and engine RPM

IV. CHECK FOR AMOUNT AND UNIFORMITY OF WATER OUTPUT
A. Operate at the selected Pressure.
B. Catch and Measure all nozzle output for known time (compare nozzle output and
change tips to get reasonable uniformity).
C. From ground speed and width of coverage calculate time to cover 1 acre.
D. From mean nozzle output per unit time (B. above), number of nozzles, and time to
cover one acre calculate gallons per acre applied. This is a basic number for dilution.
It can be changed in direct proportion to change of speed (inversely).

Note - The calibration is valid ONLY:
1) at that speed
2) at that pressure
3) at that mean nozzle output

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