ASTM E642-91(2008)
(Practice)Standard Practice for Determining Application Rates and Distribution Patterns from Aerial Application Equipment
Standard Practice for Determining Application Rates and Distribution Patterns from Aerial Application Equipment
ABSTRACT
This practice covers uniform procedures for determining and reporting application rates and distribution patterns from agricultural aircraft. The procedures covered deal with both fixed and rotary-wing aircraft equipped with either liquid or dry material distribution systems. The physical characteristics of the liquid or dry material have an effect on the application rate and the distribution patterns. If inert test solutions for materials are substituted for the materials to be applied, they shall have physical characteristics similar to those of the material to be applied. If toxic materials are used in the tests, all safety precautions prescribed. A complete procedure shall consist of five parts: the first part is the determination of the output rate from the aircraft system, the second part involves the determination of the swath distribution pattern by recovery of the applied materials from suitable collectors, the third part covers the determination of usable swath width for field applications, the fourth part discusses the determination of the rate of application of the spray mixture or dry material, and the fifth and last part is the determination of the uniformity of distribution of several swaths.
SCOPE
1.1 This practice covers uniform procedures for determining and reporting application rates and distribution patterns from agricultural aircraft. This practice should not be used for making biological performance tests.
1.2 The procedures covered deal with both fixed and rotary-wing aircraft equipped with either liquid or dry material distribution systems.
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to inch-pound units that are provided for information only and are not considered standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Designation: E642 − 91 (Reapproved2008)
Standard Practice for
Determining Application Rates and Distribution Patterns
from Aerial Application Equipment
This standard is issued under the fixed designation E642; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope the materials to be applied, they shall have physical character-
istics similar to those of the material to be applied. If toxic
1.1 Thispracticecoversuniformproceduresfordetermining
materials are used in the tests, all safety precautions prescribed
and reporting application rates and distribution patterns from
by the manufacturer and governmental authority for handling,
agricultural aircraft. This practice should not be used for
loading, application, and disposal of toxic materials shall be
making biological performance tests.
observed.
1.2 The procedures covered deal with both fixed and rotary-
3.2 Pattern tests shall be conducted, with wind speeds not
wing aircraft equipped with either liquid or dry material
exceeding 16 km/h (10 mph), measured 2.5 m (8.2 ft) above
distribution systems.
the land surface or crop canopy. If wind occurs, flights shall be
1.3 The values stated in SI units are to be regarded as
made both into and with the wind to minimize the effects of
standard. The values given in parentheses are mathematical
wind velocity on ground speed. Flights shall be made parallel
conversions to inch-pound units that are provided for informa-
to or within 20° of the direction of the wind to minimize errors
tion only and are not considered standard.
due to crosswinds.These restrictions do not apply to the output
1.4 This standard does not purport to address all of the
rate tests.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
4. Procedure
priate safety and health practices and determine the applica-
4.1 A complete procedure shall consist of five parts:
bility of regulatory limitations prior to use.
4.1.1 Determination of the output rate from the aircraft
system.
2. Referenced Documents
4.1.2 Determination of the swath distribution pattern by
2.1 ASTM Standards:
recovery of the applied materials from suitable collectors.
E726 Test Method for Particle Size Distribution of Granular
4.1.3 Determination of usable swath width for field appli-
Carriers and Granular Pesticides
cations.
2.2 ASAE Standard:
4.1.4 Determination of the rate of application of the spray
ASAE S327.1 Terminology and Definitions for Agricultural
mixture or dry material, and
Chemical Application
4.1.5 Determination of the uniformity of distribution of
3. Test Conditions several swaths.
3.1 The physical characteristics of the liquid or dry material
4.2 Output Rate Determination:
have an effect on the application rate and the distribution
4.2.1 Liquid Materials—Determine the output rate by the
patterns. If inert test solutions for materials are substituted for
amount of liquid discharged from the tank for a measured time
interval while the aircraft is in flight under normal conditions.
The time interval shall be sufficient to permit accurate mea-
This practice is under the jurisdiction of ASTM Committee E35 on Pesticides,
surement of liquid discharged and to minimize errors due to
Antimicrobials, and Alternative Control Agents and is the direct responsibility of
Subcommittee E35.22 on Pesticide Formulations and Delivery Systems.
turning the system on and off. Run the system for at least 30 s
Current edition approved Oct. 1, 2008. Published November 2008. Originally
and measure to the nearest 0.5 s. Measure the amount of liquid
approvedin1978.Lastpreviouseditionapprovedin2002asE642 – 91(2002).DOI:
used by either refilling the tank to the initial level or by
10.1520/E0642-91R08.
measuring the amount remaining in the tank and subtracting
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
from the initial amount. Measurement precision shall be 62%
Standards volume information, refer to the standard’s Document Summary page on
of the amount discharged in the test. If the liquid dispersal
the ASTM website.
system can be operated with the aircraft stationary, the test can
Available from American Society of Agricultural and Biological Engineers
(ASABE), 2950 Niles Rd., St. Joseph, MI 49085, http://www.asabe.org. be accomplished without actually flying the aircraft. Report
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E642 − 91 (2008)
output rate in litres per minute (gallons per minute), and note numbers, an appropriate area must be scanned to obtain a true
the nozzle (boom) pressure. representation of the droplet-size distribution in the sample.
4.3.3.5 Qualitative Spray Distribution Pattern
4.2.2 Dry Materials—If venturi distributors are used, deter-
Measurement—A qualitative measure of the distribution pat-
mine the output rate by measuring the amount of material
tern may be used to diagnose and correct distribution system
dischargedfromthehopperoveragiventimeintervalwhilethe
deficiencies (plugged or worn nozzles, improper size nozzles,
aircraft is in flight under normal conditions. Precision of
system leaks, improperly placed nozzles, and so forth). Quali-
measurement of time and materials as specified in 4.2.1 shall
tative distribution pattern measurement techniques may em-
apply here. Run tests with the aircraft hopper filled to at least
ploy discrete sample targets or a continuous collector placed
25 % of capacity. Report the output rate, in kilograms per
across the flight line of the aircraft. The measurement tech-
minute (pounds per minute), and the control settings used to
nique used should provide a relative or absolute measure of the
achieve this rate.
deposition on the sample surfaces across the flight line.
4.3 Swath Distribution Pattern Test:
4.3.4 Dry Material Test Procedure and Collectors:
4.3.1 Conduct this test by flying the aircraft over the center
4.3.4.1 Granular materials are normally tested by capturing
of a collection line placed at a right angle to the line of flight.
samples of the swath in buckets or collectors that are high
The collection line may be placed on the land surface or crop
enough to prevent the particles bouncing into or out of the
height (or any other height consistent with the purpose of the
containers. Collect dust or other small particles on greased
test), and shall permit collection of a representative sample of
boards or other sticky surfaces, or in shallow pans. Weigh or
the distribution pattern for the dispersed material. Fly the
count the material collected in these devices, or dissolve in a
aircraftataheightsuitedtothetypeofmaterialappliedandthe
solution for analysis as appropriate.
purpose of the application. The airspeed shall be that for the
4.3.4.2 The area of the top opening of the collectors shall be
intended application and the flight shall be level and straight.
2 2
0.1 m (1 ft ) or larger, to provide a representative sample of
Extend the collection line at least 3 m (10 ft) beyond the ends
the deposit. Spacing of the collectors along the swath shall not
of the pattern being tested. Measure ambient temperature,
exceed1m(3 ft).
humidity,andwindspeedanddirection(withrespecttotheline
4.4 Sample Analysis and Conversion of Swath Distribution
of flight) at 1 to3m(3to10ft) above the land surface or crop
Pattern Data:
canopy. Note the height of flight and the airspeed.
4.4.1 Spray Pattern Test:
4.3.2 Turn on the distribution equipment in the aircraft at
4.4.1.1 For quantifying spray deposits using tracer materi-
least 100 m (300 ft) prior to crossing the collection line, and
als, any type of sample analysis may be used that is compatible
continue operating it the same distance beyond. Run three
with the spray tracer. Examples are photoelectric colorimetry,
replications of each test. Make each replication with a separate
absorption or emission spectroscopy, and liquid or gas chro-
single pass of the aircraft. Note the direction of flight with
matography, where the sensitivity of the analysis shall be at
respect to wind direction.
least 2 ppm. After a collector is washed in accordance with
4.3.3 Spray Test Procedure and Target Collectors:
4.3.3, the concentration of tracer may be determined by use of
4.3.3.1 An inert chemical or dye tracer material may be
a standard calibration curve developed for the tracer and the
added to the contents of the spray tank, or the active chemical
analytical method employed. The rate of spray deposit in litres
may be used as a tracer for the spray pattern tests. If inert
per hectare (gallons per acre) may then be determined for each
materials are used, include suitable amounts of emulsifier,
location across the collection line as follows:
spreader-stickers, and other solvents and carriers to closely
D 5 K 3 V 3 C / C 3 A (1)
~ ! ~ !
simulate the material to be applied. t t s
4.3.3.2 The spray collection line may be composed of
discrete targets or a narrow continuous surface. Quantitative where:
analysisofthespraydepositedonthetargetcollector(s)maybe
D = deposit rate, L/ha (gal/acre),
accomplished by electronic scanning or by washing tracer
K = constant, 10 (or 1657),
2 2
material from the collector surface(s).
A = collector area, cm (in. ),
= volume of solvent used to wash tracer from target, mL,
4.3.3.3 If the pattern is determined from the amount of
t
C = concentration of tracer washed from collector, mg/L,
tracer material recovered from the line, the surface of the t
and
collector(s) shall permit all or a constant percentage of the
C = concentration of collector in original spray solution,
s
tracer to be removed by washing. If the tracer used degrades
mg/L.
due to exposure to sunlight, age, or other factors, the results
should be corrected to compensate for the degradation. If
4.4.1.2 Quantifying spray deposits using image scanning of
discrete targets are used, they may be flat sheets, or have raised
discrete or continuous sample surfaces shall utilize sufficient
edges to facilitate washing.The exposed flat surface (exclusive
size classes, preferably at least 20, to accurately define the
2 2
of raised edges) shall have an area of at least 50 cm (7.8 in. ).
droplet size distribution. A droplet size versus spread factor
Spacing of descrete targets across the swath shall not exceed 1
function covering the droplet size range encountered under test
m (3.3 ft).
conditions (temperature and relative humidity) shall be devel-
4.3.3.4 For samples that are electronically scanned to mea- oped for the sample surface material and test liquid and used in
suredepositiononthesamplesurfacebasedondropletsizeand calculating the deposit volume per unit of area.
E642 − 91 (2008)
4.4.2 Dry Material Test—If the dry material deposited in the extend beyond the center line of adjacent swaths). If the single
collection device at each location across the line of collectors swath patterns are skewed due to crosswind, simulated field
is weighed, the deposit rate may be determined in kg/ha distributions for back-and-forth applications may indicate ar-
(lb/acre) as follows: tificial irregularities. Determination of the effective swath
width from the simulated field distribution data is accom-
D 5 K 3 W /A (2)
~ !
plished by calculating the coefficient of variation (CV) in
accordance with 4.7.3, for overlapped rates of deposit obtained
where:
from sampling intervals from one swath center line to the next
D = deposit rate, kg/ha (lb/acre),
for one-direction application, or from two swath spacings for
K = constant, 10 (13 829),
back-and-forth application. Field distribution simulations will
W = weight collected, g, and
be made and CV’s calculated for swath center line spacings
2 2
A = area of collector opening, cm (or in. ).
ranging from one sampling interval width to the total width of
the single swath pattern. Swath increments for the CV calcu-
If the collected material is of a nature to make counting of
individual particles desirable, express the results as the number lations shall not be greater than the sampling interval (or one
2 2 2 2 2
meter for continuous sampling) across the swath. The largest
of particles per unit area, such as cm , 0.1 m,m (in.,ft ). If
swath width associated with the minimum acceptable CV for
the material collected is a dust, it may be desirable to use
the intended application shall be considered the effective swath
greased boards or other sticky surfaces, or shallow pans
width.
holding a solute as collectors. Procedures similar to those
outlinedin4.4.1maybeusedforanalysisofdustdepositsifthe
4.6 Rate of Application—Calculate the overall rate of appli-
dust itself can serve as the tracer material, or a suitable tracer
cation as follows:
material is mixed with the dust. Express the deposit rate in
R 5 ~Q 3 K!/~V 3 S! (3)
kilograms per hectare (pounds per acre) at each location across
the line of collectors.
where:
4.5 Plotting the Distribution Curve and Evaluating Swath
R = rate of application, L/ha or kg/ha (gal/acre or lb/acre),
Widths—Data for each test replication from 4.4.1 or 4.4.2 will
Q = output rate, L/min or kg/min (gpm or lb/min),
be plotted with the rate of deposit on the ordinate and the
K = constant, 600 (495),
location of deposit with respect to the aircraft center line on the
V = velocity over ground, km/h (mph), and
abscissa. This data, or the resulting plot, or both, will be used
S = usable swath width, m (ft).
to determine the maximum effective swath width for each
4.7 Uniformity of Distribution—Use the coefficient of varia-
replication either by inspection as described in 4.5.1 or by
tion to express the uniformity of distribution of application
simulated overlapping of swaths and statistical analysis as
resulting from multiple adjacent swaths. The multiple swaths
described in 4.5.2. The usable swath width will be obtained by
can be simulated for each distribution pattern replication
averaging the maximum effective widths determined for the
individual replicates and will be used in calculating the rate of plottedin4.5orfromactualflighttestsusingasufficientlylong
collection line. Also plot the resulting distribution to permit
application as described in 4.6.
visual examination for deposit peaks and low points that may
4.5.1 Effective Swath Width by Inspection—The distribution
occur.
pattern for most aerially applied materials should approximate
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