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ARTICLE
CALIBRATION OF TANK SPRAYERS
Calibration of Tank Sprayers How Much Water and Product Should Be Added to the Tank? Dr. Hennen Cummings • Tarleton State University
Determining how much product and water should be added to a urea herbicides which are applied at low rates like 1 oz/A. Untrained spray tank is a simple calculation once one knows the size of the area or inexperienced people may have made improper adjustments or Hennen Cummings Page 2 of 10 that a full tank or a specific volume of spray solution will cover. If a repairs to the sprayer, and one would want to calibrate a sprayer person can change the volume of spray output (nozzles) or speed of following their use of it. the sprayer, a spray tank canThere cover aare wide variety of areas, and one four main factors that affect sprayer would calibrate a sprayer for his/her particular situation. If one has There are four main output. They are: ground speed, pressure, nozzle spacing, only one nozzle and cannot vary the output of the sprayer or speed of factors that affect and nozzle flow rate (gallon per minute). The number of the sprayer, then one could physically measure the spray output of the sprayer output. nozzles a boom doesornot factorvolume into the sprayer and calculate the areaonthat a full tank a specific of calculations They are: ground spray solution would cover. Or if one has only one nozzle and cannot speed, unless there is only one nozzle, and this situation willpressure, be vary the output of the sprayer or speed of the sprayer, then one could nozzle spacing, discussed later. There are only a few items that one needs to also physically measure the area that a certain volume of water that and nozzle flow rate calibrate a sprayer. They are: collection cups (gallon that can was applied from the sprayer could cover. Then one would be able to per minute). measure volume, stopwatch, 50 ft tape measure, calculate how much product to place in the tank, like a single nozzle Theand number of wand sprayer tank.calculator. The collection cups are used to measure nozzles the on a boom does not factor spray volume from each nozzle. The stopwatch is used to into One needs measuring cups, tape measure, Calibrating a sprayer is the process varying speed, pressure, and the calculations measure both spray collection time and sprayer velocity (ft / stopwatch, and calculatorcups, to calibrate a sprayer. One: Nees measuring tape measure, nozzle size in order to deliver a specific volume both in a specific unless there is stopwatch and calculator to calibrate sec). The tape measure is used to measure both nozzle amount of time (gallons per minute) and over a specific area (gallons only one nozzle, a sprayer. spacing in inches and a 50 – 100 ft area which is used to determine sprayer velocity (ft / sec). One per acre). Turfgrass managers should calibrate a sprayer in order to and this situation should never trust a speedometer oncarrier a tractor will because tires onlater. tractors in various sizes that ensure that the correct recommended amount of product and be discussed Therecome are only a few items that onemay needs (water) are being applied per acre. If too much product is applied over to calibrate a sprayer. They are: collection cups that can measure have different circumferences which would cause the speedometer to give false readings. When a known area, the turfgrass could bethe injured, and could befill excess volume, stopwatch, ft tape measure, determining speed ofthere a sprayer, it half full of water and 50 drive it over theand turfcalculator. area thatThe willcollection be runoff or movement from the treated area. Over applying products is cups are used to measure the spray volume from each nozzle. The sprayed which will create an average situation.stopwatch Supposeis the sprayer drove a 100 ft course several times environmentally irresponsible and a waste of time and money. Sprayers used to measure both spray collection time and sprayer in both directions in a average time of 23.3 sec. are calibrated to ensure that enough product is applied over a known velocity (ft / sec). The tape measure is used to measure both nozzle area. If too little product is applied, the pest may not be controlled or spacing in inches and a 50 – 100 ft area which is used to determine not enough nitrogen would be supplied to100 the turfgrass, and the area velocity2(ft sec). One should never trust a speedometer on a ft 1mile 60 sec sprayer 60 min . 93/ mile (Note:come 2 decimal places) sizes that may have ´ lead to wasting ´ ´ = tires on tractors may need to be retreated at a higher rate which would tractor because in various 23.one 3sec 5280when ft the 1min different 1hr circumferences hr which would cause the speedometer to give time and money. Proper calibration allows to control ´ 60 false ÷ 23.3 ÷ 5280 Type = ”determining in a calculator. tank is empty like near a place where it is efficient to “100 remix ´ or 60 at the readings. When the speed of a sprayer, fill it half end of the area being treated. Calibrating automatically checks sprayer full of water and drive it over the turf area that will be sprayed which uniformity and leaks. will create average situation. the tend sprayer Record the gear and RPM setting, so the velocity can beanreproduced later.Suppose Vehicles todrove spraya 100 at 4-ft course several times in both directions in a average time of 23.3 sec. 7 mph, and people tend to walk at 2.3 to 3 mph when pushing a sprayer. Sprayers should be calibrated regularly even if one knows from prior experience the nozzle size and pressure required to achieve a specific 100 ft 1 mile 60 sec 60 min 2.93 mile Chose a GPA, GPM GPM because nozzles can wear over Calculate time and emit more(Method and more I) 23.3 sec x 5280 ft x 1 min x 1 hr = hr volume at a given pressure. In addition, nozzles can which become spray clogged, One can determine nozzle to use on a sprayer by calculating the required gallons Note: 2 decimal points replaced with different nozzles, or lost resulting a non-uniform per size minute (GPM) of sprayinsolution needed for a particular situation. application. These situations can be identified during calibration. Type “100 x 60 x 60 ÷ 23.3 ÷ 5280 = ” in a calculator Further more, if there was a leak or similar problem with the sprayer, GPA ´ MPH ´ W it would be best to find and fix the problem while the sprayer has GPM Record = the gear and RPM setting, so the velocity can be reproduced only water in it rather than a pesticide. Sprayers should be calibrated later. Vehicles5940 tend to spray at 4-7 mph, and people tend to walk at every time they are used and especially before applying very expensive 2.3 to 3 mph when pushing a sprayer. products or products that are active at very low use rates like the sulfonyl
GPM = Gallons per minute (Rate of output from one nozzle) GPA = Gallons per acre (Sprayer solution output over an acre) MPH = Miles per hour
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