What is calibration? - ANSWERS-Calibration is the process of measuring and
adjusting equipment performance
How precise should calibration be? - ANSWERS-The equipment should be within
10% of the desired output
Why do you need to consider travel speed when calibrating most kinds of
pesticide application equipment? - ANSWERS-Actual travel speed is usually one of
the main factors in calibration. The speed at which the equipment moves
influences how much pesticide is applied to a target site.
A sprayer is operated over a 400-ft test course run and it takes an average of 65
seconds to complete. What is the sprayer's speed in miles per hour? - ANSWERS-
400 ft/65 sec * 1 mile/5280 ft * 3600 sec/1 hr = 4.2 mph
What is the swath width of a boom equipped with 6 nozzles spaced 20 inches
apart? - ANSWERS-Swath width = 6 nozzles * (20in/12 in per ft) = 10 feet
You want to prepare a 4% solution for a 3-gallon backpack sprayer. How much
product should you mix into the tank? - ANSWERS-Part 1: 4% has a decimal
equivalency of 0.04
Part 2: 0.04 * 3 gal = 0.12 gallons
Part 3: Convert to ounces: 0.12 gal * 128 oz/gal = 15.4oz
,A centrifugal granular spreader was run over a test course until empty. The
spreader traveled 430 feet. The spreader has an effective swath width of 28.5
feet. The amount of material placed in the hopper for the test was 16 lbs. What is
the per acre application rate? - ANSWERS-Part 1: 28.5 ft * 430 ft/43,560 sq ft per
acre = 0.28 acres
Part 2: 16 lb/0.28 acres = 57.1 lb per acre
What is the GPA rate of a boom sprayer that has 8 nozzles spaced 18 inches apart
and traveling at a speed of 1.5 mph if the average per-nozzle output is 0.87 gpm?
- ANSWERS-Equation: GPA = GPM * 5,940/MPH * W
GPA = 0.87 GPM * 5,940/1.5 MPH * 18 in = 191.4 GPA
A product label calls for an application rate of 8 ounces of product to be applied
per treated surface acre. How much herbicide should be placed in a full 100 gallon
tank if the sprayer is calibrated to apply 15 GPA? - ANSWERS-Part 1: 100 gal/15
gpa = 6.67 acres treated with a full tank
Part 2: 8 oz * 6.67 acres = 53.4 oz herbicide
How many acres per minute are being treated if an applicator's speed is 195 feet
per minute and its effective swath width is 16 feet? - ANSWERS-16 feet * 195
fpm/43,560 sq ft = 0.07 apm
A nozzle uniformity check was performed for a 4-nozzle boom. The following
outputs were collected in a 1-minute period: 43, 47, 49 and 44 ounces. Do these 4
,nozzles apply within the acceptable 10% range? - ANSWERS-Part 1: 43 + 47 + 49 +
44/4 = 45.8oz
Part 2: 45.8oz * 0.10 = 4.8oz
Part 3: 45.8 +/- 4.8 = a range of 41.0 to 50.6
Part 4: All 4 nozzles fall within the acceptable range. No replacements are
necessary.
A pond contains 42.1 acre-feet of water. If the Never-Kill herbicide product label
recommends 0.8 ppm active ingredient for control of hydrilla, how much product
will be needed if the formulation contains 5.0% active ingredient? - ANSWERS-
Part 1: 0.8 ppm * 42.1 acre-feet * 2.7 = 90.9 lbs active ingredient
Part 2: 90.9/0.05 = 1,818 lbs of Never-Kill herbicide product
The label states to apply 2.0 quarts of product per acre for control of
waterlettuce. A direct metering system with a handheld sprayer gun will be used
to make the application from a boat. Based on the following:
- the spray volume will use 200 gallons of water per acre.
- speed is measured at 130 seconds to cover a 180 foot course.
- The sprayer gun's swath width is 12 feet
- The sprayer gun's output is measured a 4 gpm
- The herbicide withdrawal rate was found to be 2.9 opm.
What is the boat's speed in fpm? - ANSWERS-180 feet/(130 sec/60 sec per min) =
82.9 fpm
, What is the boat's speed in mph? - ANSWERS-180 ft * 3600/(5,280 * 130 sec) =
0.94 mph
OR
82.9 fpm/88 fpm per 1 mph = 094 mph
How many acres per minute will be treated? - ANSWERS-(12ft * 82.9 fpm)/43,560
sq ft = 0.023 apm
How many gallons per acre are being applied? - ANSWERS-4 gpm/0.02 apm = 200
gpa
What is the herbicide withdrawal rate in gpm? - ANSWERS-2.9 opm/128 oz per gal
= 0.023 gpm
Based on the withdrawal rate of 0.023 gpm and the other current variables, what
is the herbicide application rate in gpa? - ANSWERS-0.023 gpm/0.023 apm = 1.0
gpa
Is this herbicide rate acceptable at the current settings? - ANSWERS-Because 1.0
gpa is equivalent to 4.0 quarts, and the label rate is 2.0 quarts, this is a double
rate. Doubling the boat speed would likely result in poor weed coverage; so, a
viable option would be to replace the current orifice in the suction hose with a
smaller orifice and recheck.