ASTM E642-91(2002)

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 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.

General Information

• Status: Historical
• Publication Date: 09-Oct-2002
• ICS: 65.060.40 - Plant care equipment
• Technical Committee: E35 - Pesticides, Antimicrobials, and Alternative Control Agents
• Drafting Committee: E35.22 - Pesticide Formulations and Delivery Systems

Relations

• Replaces: ASTM E642-91(1997)e1 - Standard Practice for Determining Application Rates and Distribution Patterns from Aerial Application Equipment
• Effective Date: 10-Oct-2002
• Replaced By: ASTM E642-91(2008) - Standard Practice for Determining Application Rates and Distribution Patterns from Aerial Application Equipment
• Effective Date: 01-Oct-2008
• Referred By: ASTM F1738-23 - Standard Test Method for Determination of Deposition of Aerially Applied Oil Spill Dispersants
• Effective Date: 10-Oct-2002

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:E642–91(Reapproved 2002)
Standard Practice for
Determining Application Rates and Distribution Patterns
from Aerial Application Equipment
This standard is issued under the fixed designation E 642; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope by the manufacturer and governmental authority for handling,
loading, application, and disposal of toxic materials shall be
1.1 Thispracticecoversuniformproceduresfordetermining
observed.
and reporting application rates and distribution patterns from
3.2 Pattern tests shall be conducted, with wind speeds not
agricultural aircraft. This practice should not be used for
exceeding 16 km/h (10 mph), measured 2.5 m (8.2 ft) above
making biological performance tests.
the land surface or crop canopy. If wind occurs, flights shall be
1.2 The procedures covered deal with both fixed and rotary-
made both into and with the wind to minimize the effects of
wing aircraft equipped with either liquid or dry material
wind velocity on ground speed. Flights shall be made parallel
distribution systems.
to or within 20° of the direction of the wind to minimize errors
1.3 This standard does not purport to address all of the
due to crosswinds.These restrictions do not apply to the output
safety concerns, if any, associated with its use. It is the
rate tests.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
4. Procedure
bility of regulatory limitations prior to use.
4.1 A complete procedure shall consist of five parts:
2. Referenced Documents 4.1.1 Determination of the output rate from the aircraft
system.
2.1 ASTM Standards:
4.1.2 Determination of the swath distribution pattern by
E 726 Test Method for Particle Size Distribution of Granu-
recovery of the applied materials from suitable collectors.
lar Carriers and Granular Pesticides
4.1.3 Determination of usable swath width for field appli-
2.2 ASAE Standard:
cations.
ASAE S327.1 Terminology and Definitions forAgricultural
4.1.4 Determination of the rate of application of the spray
Chemical Application
mixture or dry material, and
3. Test Conditions
4.1.5 Determination of the uniformity of distribution of
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
the materials to be applied, they shall have physical character-
interval while the aircraft is in flight under normal conditions.
istics similar to those of the material to be applied. If toxic
The time interval shall be sufficient to permit accurate mea-
materials are used in the tests, all safety precautions prescribed
surement of liquid discharged and to minimize errors due to
turning the system on and off. Run the system for at least 30 s
and measure to the nearest 0.5 s. Measure the amount of liquid
This practice is under the jurisdiction of ASTM Committee E35 on Pesticides
and is the direct responsibility of Subcommittee E35.22 on Pesticide Formulations
used by either refilling the tank to the initial level or by
and Delivery Systems.
measuring the amount remaining in the tank and subtracting
Current edition approved Oct. 10, 2002. Published March 2003. Originally
e1 from the initial amount. Measurement precision shall be 62%
approved in 1978. Last previous edition approved in 1997 as E 642 – 91 (1997) .
of the amount discharged in the test. If the liquid dispersal
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
system can be operated with the aircraft stationary, the test can
Standards volume information, refer to the standard’s Document Summary page on
be accomplished without actually flying the aircraft. Report
the ASTM website.
output rate in litres per minute (gallons per minute), and note
AvailablefromAmericanSocietyofAgriculturalEngineers,2950NilesRd.,St.
Joseph, MI 49085. the nozzle (boom) pressure.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E642–91 (2002)
4.2.2 Dry Materials—If venturi distributors are used, deter- 4.3.3.5 Qualitative Spray Distribution Pattern
mine the output rate by measuring the amount of material Measurement—A qualitative measure of the distribution pat-
dischargedfromthehopperoveragiventimeintervalwhilethe
tern may be used to diagnose and correct distribution system
aircraft is in flight under normal conditions. Precision of
deficiencies (plugged or worn nozzles, improper size nozzles,
measurement of time and materials as specified in 4.2.1 shall
system leaks, improperly placed nozzles, and so forth). Quali-
apply here. Run tests with the aircraft hopper filled to at least
tative distribution pattern measurement techniques may em-
25 % of capacity. Report the output rate, in kilograms per
ploy discrete sample targets or a continuous collector placed
minute (pounds per minute), and the control settings used to
across the flight line of the aircraft. The measurement tech-
achieve this rate.
nique used should provide a relative or absolute measure of the
4.3 Swath Distribution Pattern Test:
deposition on the sample surfaces across the flight line.
4.3.1 Conduct this test by flying the aircraft over the center 4.3.4 Dry Material Test Procedure and Collectors:
of a collection line placed at a right angle to the line of flight.
4.3.4.1 Granular materials are normally tested by capturing
The collection line may be placed on the land surface or crop
samples of the swath in buckets or collectors that are high
height (or any other height consistent with the purpose of the
enough to prevent the particles bouncing into or out of the
test), and shall permit collection of a representative sample of
containers. Collect dust or other small particles on greased
the distribution pattern for the dispersed material. Fly the
boards or other sticky surfaces, or in shallow pans. Weigh or
aircraftataheightsuitedtothetypeofmaterialappliedandthe
count the material collected in these devices, or dissolve in a
purpose of the application. The airspeed shall be that for the
solution for analysis as appropriate.
intended application and the flight shall be level and straight.
4.3.4.2 The area of the top opening of the collectors shall be
Extend the collection line at least 3 m (10 ft) beyond the ends
2 2
0.1 m (1 ft ) or larger, to provide a representative sample of
of the pattern being tested. Measure ambient temperature,
the deposit. Spacing of the collectors along the swath shall not
humidity,andwindspeedanddirection(withrespecttotheline
exceed1m(3 ft).
of flight) at 1 to3m(3to10ft) above the land surface or crop
4.4 Sample Analysis and Conversion of Swath Distribution
canopy. Note the height of flight and the airspeed.
Pattern Data:
4.3.2 Turn on the distribution equipment in the aircraft at
4.4.1 Spray Pattern Test:
least 100 m (300 ft) prior to crossing the collection line, and
continue operating it the same distance beyond. Run three 4.4.1.1 For quantifying spray deposits using tracer materi-
replications of each test. Make each replication with a separate als, any type of sample analysis may be used that is compatible
single pass of the aircraft. Note the direction of flight with with the spray tracer. Examples are photoelectric colorimetry,
respect to wind direction. absorption or emission spectroscopy, and liquid or gas chro-
matography, where the sensitivity of the analysis shall be at
4.3.3 Spray Test Procedure and Target Collectors:
least 2 ppm. After a collector is washed in accordance with
4.3.3.1 An inert chemical or dye tracer material may be
4.3.3, the concentration of tracer may be determined by use of
added to the contents of the spray tank, or the active chemical
a standard calibration curve developed for the tracer and the
may be used as a tracer for the spray pattern tests. If inert
analytical method employed. The rate of spray deposit in litres
materials are used, include suitable amounts of emulsifier,
per hectare (gallons per acre) may then be determined for each
spreader-stickers, and other solvents and carriers to closely
location across the collection line as follows:
simulate the material to be applied.
4.3.3.2 The spray collection line may be composed of D 5 ~K 3 V 3 C !/~C 3 A! (1)
t t s
discrete targets or a narrow continuous surface. Quantitative
analysisofthespraydepositedonthetargetcollector(s)maybe
where:
accomplished by electronic scanning or by washing tracer
D = deposit rate, L/ha (gal/acre),
material from the collector surface(s).
K = constant, 10 (or 1657),
2 2
4.3.3.3 If the pattern is determined from the amount of
A = collector area, cm (in. ),
tracer material recovered from the line, the surface of the = volume of solvent used to wash tracer from target,
t
collector(s) shall permit all or a constant percentage of the mL,
C = concentration of tracer washed from collector, mg/L,
tracer to be removed by washing. If the tracer used degrades
t
and
due to exposure to sunlight, age, or other factors, the results
C = concentration of collector in original spray solution,
should be corrected to compensate for the degradation. If s
mg/L.
discrete targets are used, they may be flat sheets, or have raised
edges to facilitate washing.The exposed flat surface (exclusive
4.4.1.2 Quantifying spray deposits using image scanning of
2 2
of raised edges) shall have an area of at least 50 cm (7.8 in. ). discrete or continuous sample surfaces shall utilize sufficient
Spacing of descrete targets across the swath shall not exceed 1
size classes, preferably at least 20, to accurately define the
m (3.3 ft).
droplet size distribution. A droplet size versus spread factor
function covering the droplet size range encountered under test
4.3.3.4 For samples that are electronically scanned to mea-
suredepositiononthesamplesurfacebasedondropletsizeand conditions (temperature and relative humidity) shall be devel-
oped for the sample surface material and test liquid and used in
numbers, an appropriate area must be scanned to obtain a true
representation of the droplet-size distribution in the sample. calculating the deposit volume per unit of area.
E642–91 (2002)
4.4.2 Dry Material Test—Ifthedrymaterialdepositedinthe swath patterns are skewed due to crosswind, simulated field
collection device at each location across the line of collectors distributions for back-and-forth applications may indicate ar-
is weighed, the deposit rate may be determined in kg/ha tificial irregularities. Determination of the effective swath
(lb/acre) as follows: width from the simulated field distribution data is accom-
plished by calculating the coefficient of variation (CV) in
D 5 ~K 3 W!/A (2)
accordance with 4.7.3, for overlapped rates of deposit obtained
from sampling intervals from one swath center line to the next
where:
for one-direction application, or from two swath spacings for
D = deposit rate, kg/ha (lb/acre),
back-and-forth application. Field distribution simulations will
K = constant, 10 (13 829),
be made and CV’s calculated for swath center line spacings
W = weight collected, g, and
ranging from one sampling interval width to the total width of
2 2
A = area of collector opening, cm (or in. ).
the single swath pattern. Swath increments for the CV calcu-
If the collected material is of a nature to make counting of
lations shall not be greater than the sampling interval (or one
individual particles desirable, express the results as the number
meter for continuous sampling) across the swath. The largest
2 2 2 2 2
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
4.6 Rate of Application—Calculate the overall rate of ap-
outlinedin4.4.1maybeusedforanalysisofdustdepositsifthe
plication as follows:
dust itself can serve as the tracer material, or a suitable tracer
R 5 ~Q 3 K!/~V 3 S! (3)
material is mixed with the dust. Express the deposit rate in
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),
K = constant, 600 (495),
be plotted with the rate of deposit on the ordinate and the
V = velocity over ground, km/h (mph), and
locationofdepositwithrespecttotheaircraftcenterlineonthe
S = usable swath width, m (ft).
abscissa. This data, or the resulting plot, or both, will be used
4.7 Uniformity of Distribution—Usethecoefficientofvaria-
to determine the maximum effective swath width for each
tion to express the uniformity of distribution of application
replication either by inspection as described in 4.5.1 or by
resulting from multiple adjacent swaths. The multiple swaths
simulated overlapping of swaths and statistical analysis as
can be simulated for each distribution pattern replication
described in 4.5.2. The usable swath width will be obtained by
plottedin4.5orfromactualflighttestsusingasufficientlylong
averaging the maximum effective widths determined for the
collection line. Also plot the resulting distribution to permit
individual replicates and will be used in calculating the rate of
visual examination for deposit peaks and low points that may
application as described in 4.6.
occur.
4.5.1 Effective Swath Width by Inspection—The distribution
4.7.1 Simulated Field Distribution:
pattern for most aerially applied materials should approximate
4.7.1.1 Determine the simulated field distribution for each
either a triangular or a trapezoidal pattern with the maximum
swath distribution pattern obtained in 4.3 using the effective
rate of deposit under the flight path of the aircraft. The rate of
swath width determined in accordance with 4.5.1 or 4.5.2.
deposit should taper off evenly at the edges of the pattern. The
Develop the simulated fi
...