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S T A N D A R D ASABE is a professional and technical organization, of members worldwide, who are dedicated to advancement of engineering applicable to agricultural, food, and biological systems. ASABE Standards are consensus documents developed and adopted by the American Society of Agricultural and Biological Engineers to meet standardization needs within the scope of the Society; principally agricultural field equipment, farmstead equipment, structures, soil and wa
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  STANDARD ASABE is a professional and technical organization, of members worldwide, who are dedicated to advancement ofengineering applicable to agricultural, food, and biological systems. ASABE Standards are consensus documentsdeveloped and adopted by the American Society of Agricultural and Biological Engineers to meet standardizationneeds within the scope of the Society; principally agricultural field equipment, farmstead equipment, structures, soiland water resource management, turf and landscape equipment, forest engineering, food and process engineering,electric power applications, plant and animal environment, and waste management. NOTE:  ASABE Standards, Engineering Practices, and Data are informational and advisory only. Their use byanyone engaged in industry or trade is entirely voluntary. The ASABE assumes no responsibility for results attrib-utable to the application of ASABE Standards, Engineering Practices, and Data. Conformity does not ensurecompliance with applicable ordinances, laws and regulations. Prospective users are responsible for protectingthemselves against liability for infringement of patents.ASABE Standards, Engineering Practices, and Data initially approved prior to the society name change in July of2005 are designated as ‘ASAE’, regardless of the revision approval date. Newly developed Standards, EngineeringPractices and Data approved after July of 2005 are designated as ‘ASABE’.Standards designated as ‘ANSI’ are American National Standards as are all ISO adoptions published by ASABE.Adoption as an American National Standard requires verification by ANSI that the requirements for due process,consensus, and other criteria for approval have been met by ASABE.Consensus is established when, in the judgment of the ANSI Board of Standards Review, substantial agreement hasbeen reached by directly and materially affected interests. Substantial agreement means much more than a simplemajority, but not necessarily unanimity. Consensus requires that all views and objections be considered, and that aconcerted effort be made toward their resolution. CAUTION NOTICE:  ASABE and ANSI standards may be revised or withdrawn at any time. Additionally, proceduresof ASABE require that action be taken periodically to reaffirm, revise, or withdraw each standard.Copyright American Society of Agricultural and Biological Engineers. All rights reserved.ASABE, 2950 Niles Road, St. Joseph, MI 49085-9659, USA ph. 269-429-0300, fax 269-429-3852, hq@asabe.org A NSI/ASAE S572.1 MAR2009Spray Nozzle Classification by Droplet Spectra    ANSI/ASAE S572.1 MAR2009Approved March 2009 as an American National Standard Spray Nozzle Classification by Droplet Spectra Developed by the ASAE Pest Control and Fertilizer Application Committee; approved by the Power and Machinery Division Standards Committee; adopted by ASAE August 1999; reaffirmed February 2004; revised March 2009; approved as an American National Standard March 2009. Keywords:  Chemicals, Drop size, Droplet, Fertilizer, Nozzle, Spray 1 Purpose and scope 1.1  This Standard defines droplet spectrum categories for theclassification of spray nozzles, relative to specified reference fan nozzlesdischarging spray into static air or so that no stream of air enhancesatomization. The purpose of classification is to provide the nozzle userwith droplet size information primarily to indicate off-site spray driftpotential and secondarily for application efficacy. 1.2  This Standard defines a means for  relative nozzle comparisons only based on droplet size  . Other spray drift and application efficacy factors,such as droplet discharge trajectory, height, and velocity, air bubbleinclusion; droplet evaporation; and impaction on target are examples offactors not addressed by the current Standard. 2 General 2.1  Liquid flow rate, liquid pressure, and physical changes to nozzlegeometry and operation can affect the nozzle classification. A givennozzle can be classified into one or more droplet size categories,depending on the selection of flow rate, operating pressure, and otheroperational conditions. 2.2  Generally the Standard is based on spraying water through thereference nozzles and nozzles to be classified. However, spray liquidproperties may affect droplet sizes and should be considered by the enduser. Besides water, a surfactant-water mixture, with a dynamic surfacetension of 40±2 dynes/cm at 10 to 20 ms, such as 9%   wt/wt  isopropanol or 0.1%   v/v   Surfynol TM TG-E surfactant in water should besprayed through the nozzles to be classified   1   that are claimed toreduce spray drift, or   2   that utilize pre-orifices or internal turbulencechambers  especially for cases near a threshold between classification categories  . If differing classifications   see 6 Nozzle classificationprocedures for statistical basis   are determined for water versus amixture of water and surfactant, the finer of the two classifications shouldbe reported. 2.3  Presentation of nozzle classification categories to nozzle usersshould use the standard category terms from 3.3. The presentation mayuse the symbols or color codes identified in 3.3, provided thecorresponding standard category terms are identified in the presentation. 3 Reference flat spray nozzles 3.1  The droplet spectra produced by single, elliptical orifice referencenozzles with specified,   1   liquid mixture   water  ,   2   liquid flow rates,   3  operating pressures, and   4   spray angles, all of which are specified bythis Standard   see 3.5  , establish the threshold of division betweennozzle classification categories. 3.1.1  Reference nozzle sets should be periodically checked, throughlaser droplet size testing, for consistency in droplet size production. 3.2  Reference nozzles shall not be subjected to wear-inducingconditions that could alter orifice size, shape, smoothness, flow rate, orspray angle. 3.3  Classification categories, symbols, and corresponding color codesare the following:Classification category Symbol Color codeExtremely fine XF PurpleVery fine VF RedFine F OrangeMedium M YellowCoarse C BlueVery coarse VC GreenExtremely coarse XC WhiteUltra Coarse UC Black 3.4  Reference flow rate and operating pressure are specified for eachreference nozzle, since droplet size spectra from pressure atomizers areaffected by flow rate and operating pressure. The included angle of thefan spray, nominal rated flow rate, reference flow rate, and referenceoperating pressure are specified   see 3.5  . It should be noted that anozzle body strainer, or screen,  is not used   for any nozzle tip in thisStandard. 3.5  Classification category thresholds, nozzle spray angles, nominalrated flow ratings at 276 kPa   40 psi  , reference flow ratings, andreference operating pressures are shown in Table 1. 4 Droplet sizing 4.1  The droplet spectra from the reference nozzles, and from nozzles tobe classified, should be measured with a laser-based instrument.Commercial droplet sizing instruments typically use either   1   laserdiffraction,   2   laser imaging, or   3   laser-based phase-Dopplertechniques. Instrument use should minimize the measurement ofinteractions that could occur between the instrument and droplets in-flightin the spray. Instrument technologies other than laser-based may beused provided that accuracy and repeatability are comparable with that oflaser instruments. 4.1.1  Verification or calibration to known standards of any measurementmethod is essential. Instrument particulars, such as size rangeconfiguration, obscuration, multiple scattering, verification, droplet pathangle, calibration, and repeatability, shall be addressed such thataccurate and repeatable day-to-day measurements are obtained. 4.2  Nozzles are oriented to discharge the spray to allow for scanning theentire spray plume by the laser instrument. The height of the laser belowthe nozzle, or the distance between the nozzle discharge andmeasurement point, should range from 200 mm   8 in.   to 500 mm   20in.  . However, exceptions to this distance range may be necessary toreduce fouling of the instrument lens. 4.3  Droplet size measurement must ensure that a representative,cross-sectional sample of the spray plume is obtained. Acceptablemethods include traversing the nozzle through the laser during datasampling, or by calculating droplet sizes by merging data of multiplereadings from representative samples of the spray plume. The methodchosen should be consistent between reference nozzles and nozzlesbeing classified. ASTM Standards addressing instrument use and spraysampling should always be consulted for best measurement procedures. ANSI/ASAE S572.1 MAR2009 1ASABE STANDARDS 2009  4.4  A minimum of three separate, replicate measurements shall beaveraged to establish the cumulative volume-versus-droplet size spectrarelationship, including values of  D  v0.1 ,  D  v0.5 , and  D  v0.9  . The exact numberof replicate measurements shall be determined based on the desiredstandard deviation and resulting resolution in classification   see 6  . 4.5  Tap water is the test liquid for reference nozzle droplet sizingdeterminations. Exceptions to using water alone for nozzles to beclassified are specified in 2.2. Ambient temperature and measurementtechnique should result in negligible droplet evaporation. 5 Reference graph of classification droplet spectra 5.1  A reference graph for nozzle classification shall be established fromdroplet size spectra measurements obtained for all of the referencenozzles. Droplet diameter   microns   is plotted versus the cumulativespray volume   fraction or percent   ordinate   for five reference nozzlesas an example reference graph. These curves define the classificationthresholds between categories. 5.2  Cumulative volume for the reference graph shall range from 10 to 90percent. The graph can be simplified by using computed values of  D  v0.1 , D  v0.5 , and  D  v0.9 . An example reference graph developed frommeasurements averaged from three types of laser instruments is shownin figure 1. 5.3  Droplet spectra measurements for   A   reference nozzles  and    B  nozzles to be classified shall be performed with the same   1   instrument,  2   measurement method,   3   sampling technique,   4   scanningtechnique,   5   operator; and   6   similar environmental condition. Anydeviation in these six factors may void the accuracy of the classification.The reference graph shall be verified before and after measurements aretaken to classify nozzles. The frequency of graph verification shouldensure that repeatable classification results are obtained throughouttesting. 6 Nozzle classification procedures 6.1  Sprays from nozzles to be classified are measured on the sameanalyzer at the same settings as for the reference nozzles   see 5Reference graph of classification droplet spectra  . Nozzle classificationsare determined from plotting cumulative volume versus droplet sizespectra, namely the computed values of  D  v0.1 ,  D  v0.5 , and  D  v0.9  onto thereference graph. The classification is determined based on where thedroplet size spectra fall on the reference graph relative to the referencenozzles.  One standard deviation of each reference nozzle measurement above each threshold curve determines the actual upper limit for the classification category falling below the threshold curve. 6.2  Steps of the procedure include:1. Calibrate or verify the droplet sizing instrument   see 4 Dropletsizing  2. Calibrate flow rate from reference nozzles to achieve referencedischarge flow rate   see specifications in 3.5  Table 1 – Classification category threshold values for flat spray nozzles Nominalrated flow rate 1 Reference flow rate 2 Referenceoperating pressure 3 Classificationcategory thresholdNozzlespray angle   °   L/min   gpm   L/min   gpm   kPa   psi  XF / VF IP-16 4 , 30 0.075 0.032 0.036 0.010 550 79.8VF / F 110 0.38 0.10 0.48 0.13 450 65.3F / M 110 1.14 0.30 1.18 0.31 300 43.5M / C 110 2.27 0.60 1.93 0.51 200 29.0C / VC 80 3.03 0.80 2.88 0.76 250 36.3VC / XC 65 3.78 1.00 3.22 0.85 200 29.0XC / UC 65 5.68 1.50 4.92 1.30 150 21.7 1 Nominal rated flow rate is at 276 kPa   40 psi   and is for nozzle size confirmation only; for IP-16 nominal rating is 0.75L/m at 6895 kPa   1000psi  . 2 Reference flow rate is the actual rate used and has a tolerance of ±0.04 L/min   ±0.01 gpm  . Reference flow rate was determined for this Standardfrom  Q  = k    P   . The orifice coefficient   k    for each single, elliptical orifice reference nozzle is calculated from the nominal rated condition. IP-16 datais from the manufacturer MeeFog™. The reference operating pressure   P    is listed in the above table. Tolerances for the reference operating pressureare described in the following footnote. 3 Reference operating pressure is the hydraulic pressure used to obtain the reference flow rate and should be within a tolerance range of ±3.4 kPa  ±0.5 psi   of the value tabled above. If the tolerance reference flow rate at the tolerance reference operating pressure cannot simultaneously beachieved, a different nozzle tip should be selected. All pressures are measured with a test gage with a minimum accuracy of 2 kPa   0.25 psi  accuracy grade =3A  . Test pressure is obtained via a capillary tube connected to a tee that accommodates the nozzle body to minimize flowrestrictions and potential pressure drop between the capillary and nozzle tip. No nozzle strainer is present in the nozzle body. 4 IP-16 is a pin deflector fog nozzle from MeeFog™. Figure 1 – Sample reference graph developed from measurements aver-aged from three types of laser instruments. NOTE: To view figure in colorplease go to http://www.asabe.org/standards/images/s572images.html ANSI/ASAE S572.1 MAR20092 ASABE STANDARDS 2009  3. Measure droplet spectra from the reference nozzles   see 3 Ref-erence flat spray nozzles  4. Plot the reference graph   see 5 Reference graph of classifica-tion droplet spectra  5. Measure the droplet spectrum for the nozzle, pressure, flow rate,geometry, and operational combination to be classified6. Plot the measured droplet spectrum on the reference graph7. Determine the classification based on the category where themeasured spectrum falls  - taking into account one standard deviation of the reference nozzle measurement above the threshold curve as the statistical basis for decisions involving classifications close to the reference curves. One standard de- viation above the reference curve is the upper limit for the cor- responding lower category. 6.3  The measured droplet spectrum for a given nozzle/pressurecombination should fall in a single classification category, withoutintercepting or crossing a reference threshold curve. In the event areference threshold division is intercepted or crossed, the finer of theclassification categories shall be reported to indicate the smallest dropletsize of the categories involved, ignoring the region of Dv0.9 to notpenalize narrow droplet size distribution atomizers.  Again, the standard deviation in measurement accuracy of the threshold curve should be taken into account, even when curves cross threshold curves    see 6.1and 6.2   . Annex A  informative  Additional spray solution for nozzles claimedto reduce drift Surfactant source1.1  Surfynol TM TG-E surfactant as noted in 2.2 as a means of obtainingthe specified surfactant–water mixture is available from Air Products andChemicals Inc., Allentown, PA. 800-345-3148 Annex B  informative  References The following standards contain provisions that pertain to this Standard.All standards are subject to revision, and users of this Standard areencouraged to apply the most recent edition of the standards indicatedbelow.ASAE S327.3,  Terminology and Definitions for Agricultural Chemical Applications  ASTM E1260,  Standard Test Method for Determining Liquid Drop Size Characteristics in a Spray Using Optical Non-Imaging Light-Scattering Instruments  ASTM E1296,  Standard Terminology Related to Liquid Particle Statistics  ANSI/ASAE S572.1 MAR2009 3ASABE STANDARDS 2009
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