1、Designation: E 642 91 (Reapproved 2008)Standard Practice forDetermining Application Rates and Distribution Patternsfrom Aerial Application Equipment1This standard is issued under the fixed designation E 642; the number immediately following the designation indicates the year oforiginal adoption or,
2、in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers uniform procedures for determiningand reporting application
3、rates and distribution patterns fromagricultural aircraft. This practice should not be used formaking biological performance tests.1.2 The procedures covered deal with both fixed and rotary-wing aircraft equipped with either liquid or dry materialdistribution systems.1.3 The values stated in SI unit
4、s are to be regarded asstandard. The values given in parentheses are mathematicalconversions to inch-pound units that are provided for informa-tion only and are not considered standard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is the
5、responsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E 726 Test Method for Particle Size Distribution of Granu-lar Carriers and Granular Pes
6、ticides2.2 ASAE Standard:ASAE S327.1 Terminology and Definitions for AgriculturalChemical Application33. Test Conditions3.1 The physical characteristics of the liquid or dry materialhave an effect on the application rate and the distributionpatterns. If inert test solutions for materials are substit
7、uted forthe materials to be applied, they shall have physical character-istics similar to those of the material to be applied. If toxicmaterials are used in the tests, all safety precautions prescribedby the manufacturer and governmental authority for handling,loading, application, and disposal of t
8、oxic materials shall beobserved.3.2 Pattern tests shall be conducted, with wind speeds notexceeding 16 km/h (10 mph), measured 2.5 m (8.2 ft) abovethe land surface or crop canopy. If wind occurs, flights shall bemade both into and with the wind to minimize the effects ofwind velocity on ground speed
9、. Flights shall be made parallelto or within 20 of the direction of the wind to minimize errorsdue to crosswinds. These restrictions do not apply to the outputrate tests.4. Procedure4.1 A complete procedure shall consist of five parts:4.1.1 Determination of the output rate from the aircraftsystem.4.
10、1.2 Determination of the swath distribution pattern byrecovery of the applied materials from suitable collectors.4.1.3 Determination of usable swath width for field appli-cations.4.1.4 Determination of the rate of application of the spraymixture or dry material, and4.1.5 Determination of the uniform
11、ity of distribution ofseveral swaths.4.2 Output Rate Determination:4.2.1 Liquid MaterialsDetermine the output rate by theamount of liquid discharged from the tank for a measured timeinterval while the aircraft is in flight under normal conditions.The time interval shall be sufficient to permit accur
12、ate mea-surement of liquid discharged and to minimize errors due toturning the system on and off. Run the system for at least 30 sand measure to the nearest 0.5 s. Measure the amount of liquidused by either refilling the tank to the initial level or bymeasuring the amount remaining in the tank and s
13、ubtractingfrom the initial amount. Measurement precision shall be 62%of the amount discharged in the test. If the liquid dispersalsystem can be operated with the aircraft stationary, the test can1This practice is under the jurisdiction of ASTM Committee E35 on Pesticidesand Alternative Control Agent
14、s and is the direct responsibility of SubcommitteeE35.22 on Pesticide Formulations and Delivery Systems.Current edition approved Oct. 1, 2008. Published November 2008. Originallyapproved in 1978. Last previous edition approved in 2002 as E 642 91(2002).2For referenced ASTM standards, visit the ASTM
15、website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American Society of Agricultural and Biological Engineers(ASABE), 2950 Niles Rd., St. Joseph
16、, MI 49085, http:/www.asabe.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.be accomplished without actually flying the aircraft. Reportoutput rate in litres per minute (gallons per minute), and notethe nozzle (boom) pressure.4.2
17、.2 Dry MaterialsIf venturi distributors are used, deter-mine the output rate by measuring the amount of materialdischarged from the hopper over a given time interval while theaircraft is in flight under normal conditions. Precision ofmeasurement of time and materials as specified in 4.2.1 shallapply
18、 here. Run tests with the aircraft hopper filled to at least25 % of capacity. Report the output rate, in kilograms perminute (pounds per minute), and the control settings used toachieve this rate.4.3 Swath Distribution Pattern Test:4.3.1 Conduct this test by flying the aircraft over the centerof a c
19、ollection line placed at a right angle to the line of flight.The collection line may be placed on the land surface or cropheight (or any other height consistent with the purpose of thetest), and shall permit collection of a representative sample ofthe distribution pattern for the dispersed material.
20、 Fly theaircraft at a height suited to the type of material applied and thepurpose of the application. The airspeed shall be that for theintended application and the flight shall be level and straight.Extend the collection line at least 3 m (10 ft) beyond the endsof the pattern being tested. Measure
21、 ambient temperature,humidity, and wind speed and direction (with respect to the lineof flight) at 1 to3m(3to10ft)above the land surface or cropcanopy. Note the height of flight and the airspeed.4.3.2 Turn on the distribution equipment in the aircraft atleast 100 m (300 ft) prior to crossing the col
22、lection line, andcontinue operating it the same distance beyond. Run threereplications of each test. Make each replication with a separatesingle pass of the aircraft. Note the direction of flight withrespect to wind direction.4.3.3 Spray Test Procedure and Target Collectors:4.3.3.1 An inert chemical
23、 or dye tracer material may beadded to the contents of the spray tank, or the active chemicalmay be used as a tracer for the spray pattern tests. If inertmaterials are used, include suitable amounts of emulsifier,spreader-stickers, and other solvents and carriers to closelysimulate the material to b
24、e applied.4.3.3.2 The spray collection line may be composed ofdiscrete targets or a narrow continuous surface. Quantitativeanalysis of the spray deposited on the target collector(s) may beaccomplished by electronic scanning or by washing tracermaterial from the collector surface(s).4.3.3.3 If the pa
25、ttern is determined from the amount oftracer material recovered from the line, the surface of thecollector(s) shall permit all or a constant percentage of thetracer to be removed by washing. If the tracer used degradesdue to exposure to sunlight, age, or other factors, the resultsshould be corrected
26、 to compensate for the degradation. Ifdiscrete targets are used, they may be flat sheets, or have raisededges to facilitate washing. The exposed flat surface (exclusiveof raised edges) shall have an area of at least 50 cm2(7.8 in.2).Spacing of descrete targets across the swath shall not exceed 1m (3
27、.3 ft).4.3.3.4 For samples that are electronically scanned to mea-sure deposition on the sample surface based on droplet size andnumbers, an appropriate area must be scanned to obtain a truerepresentation of the droplet-size distribution in the sample.4.3.3.5 Qualitative Spray Distribution PatternMe
28、asurementA qualitative measure of the distribution pat-tern may be used to diagnose and correct distribution systemdeficiencies (plugged or worn nozzles, improper size nozzles,system leaks, improperly placed nozzles, and so forth). Quali-tative distribution pattern measurement techniques may em-ploy
29、 discrete sample targets or a continuous collector placedacross the flight line of the aircraft. The measurement tech-nique used should provide a relative or absolute measure of thedeposition on the sample surfaces across the flight line.4.3.4 Dry Material Test Procedure and Collectors:4.3.4.1 Granu
30、lar materials are normally tested by capturingsamples of the swath in buckets or collectors that are highenough to prevent the particles bouncing into or out of thecontainers. Collect dust or other small particles on greasedboards or other sticky surfaces, or in shallow pans. Weigh orcount the mater
31、ial collected in these devices, or dissolve in asolution for analysis as appropriate.4.3.4.2 The area of the top opening of the collectors shall be0.1 m2(1 ft2) or larger, to provide a representative sample ofthe deposit. Spacing of the collectors along the swath shall notexceed1m(3ft).4.4 Sample An
32、alysis and Conversion of Swath DistributionPattern Data:4.4.1 Spray Pattern Test:4.4.1.1 For quantifying spray deposits using tracer materi-als, any type of sample analysis may be used that is compatiblewith the spray tracer. Examples are photoelectric colorimetry,absorption or emission spectroscopy
33、, and liquid or gas chro-matography, where the sensitivity of the analysis shall be atleast 2 ppm. After a collector is washed in accordance with4.3.3, the concentration of tracer may be determined by use ofa standard calibration curve developed for the tracer and theanalytical method employed. The
34、rate of spray deposit in litresper hectare (gallons per acre) may then be determined for eachlocation across the collection line as follows:D 5 K 3 Vt3 Ct!/Cs3 A! (1)where:D = deposit rate, L/ha (gal/acre),K = constant, 105(or 1657),A = collector area, cm2(in.2),t= volume of solvent used to wash tra
35、cer from target,mL,Ct= concentration of tracer washed from collector, mg/L,andCs= concentration of collector in original spray solution,mg/L.4.4.1.2 Quantifying spray deposits using image scanning ofdiscrete or continuous sample surfaces shall utilize sufficientsize classes, preferably at least 20,
36、to accurately define thedroplet size distribution. A droplet size versus spread factorfunction covering the droplet size range encountered under testconditions (temperature and relative humidity) shall be devel-oped for the sample surface material and test liquid and used incalculating the deposit v
37、olume per unit of area.E 642 91 (2008)24.4.2 Dry Material TestIf the dry material deposited in thecollection device at each location across the line of collectorsis weighed, the deposit rate may be determined in kg/ha(lb/acre) as follows:D 5 K 3 W!/A (2)where:D = deposit rate, kg/ha (lb/acre),K = co
38、nstant, 105(13 829),W = weight collected, g, andA = area of collector opening, cm2(or in.2).If the collected material is of a nature to make counting ofindividual particles desirable, express the results as the numberof particles per unit area, such as cm2, 0.1 m2,m2(in.2,ft2). Ifthe material collec
39、ted is a dust, it may be desirable to usegreased boards or other sticky surfaces, or shallow pansholding a solute as collectors. Procedures similar to thoseoutlined in 4.4.1 may be used for analysis of dust deposits if thedust itself can serve as the tracer material, or a suitable tracermaterial is
40、mixed with the dust. Express the deposit rate inkilograms per hectare (pounds per acre) at each location acrossthe line of collectors.4.5 Plotting the Distribution Curve and Evaluating SwathWidthsData for each test replication from 4.4.1 or 4.4.2 willbe plotted with the rate of deposit on the ordina
41、te and thelocation of deposit with respect to the aircraft center line on theabscissa. This data, or the resulting plot, or both, will be usedto determine the maximum effective swath width for eachreplication either by inspection as described in 4.5.1 or bysimulated overlapping of swaths and statist
42、ical analysis asdescribed in 4.5.2. The usable swath width will be obtained byaveraging the maximum effective widths determined for theindividual replicates and will be used in calculating the rate ofapplication as described in 4.6.4.5.1 Effective Swath Width by InspectionThe distributionpattern for
43、 most aerially applied materials should approximateeither a triangular or a trapezoidal pattern with the maximumrate of deposit under the flight path of the aircraft. The rate ofdeposit should taper off evenly at the edges of the pattern. Theeffective swath width may be determined as the distancebet
44、ween points on either side of the pattern where the rate ofdeposit equals one half of the maximum rate for the pattern. Ifa pattern contains spurious peak deposit rates or other irregu-larities, it should either not be used to determine effectiveswath width or such irregularities should be discounte
45、d.4.5.2 Effective Swath Width by Simulated Overlapping andStatistical AnalysisThe single swath patterns shall be plottedaround the aircraft center line as multiple adjacent swaths, withadditive deposits in the overlapped regions to obtain a com-posite plot showing simulated field distribution. Since
46、 thedistribution patterns often are not perfectly symmetrical, plotsmay be prepared to simulate both the one-direction andback-and-forth methods of application. Enough patterns mustbe overlapped to ensure a representative simulated field distri-bution that would be unaffected by additional swaths (a
47、minimum of four swaths for one-direction or five for back-and-forth application, if the tails of the distribution patternextend beyond the center line of adjacent swaths). If the singleswath patterns are skewed due to crosswind, simulated fielddistributions for back-and-forth applications may indica
48、te ar-tificial irregularities. Determination of the effective swathwidth from the simulated field distribution data is accom-plished by calculating the coefficient of variation (CV) inaccordance with 4.7.3, for overlapped rates of deposit obtainedfrom sampling intervals from one swath center line to
49、 the nextfor one-direction application, or from two swath spacings forback-and-forth application. Field distribution simulations willbe made and CVs calculated for swath center line spacingsranging from one sampling interval width to the total width ofthe single swath pattern. Swath increments for the CV calcu-lations shall not be greater than the sampling interval (or onemeter for continuous sampling) across the swath. The largestswath width associated with the minimum acceptable CV forthe intended application shall be considered the effective swathwidth.4.6 Rate of Ap
