ASTM E642-91(1997)e1
(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
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 the safety problems 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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e1
Designation: E 642 – 91 (Reapproved 1997)
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.
e NOTE—Paragraph 3.2 was corected editorially in April 1997.
1. Scope the land surface or crop canopy. If wind occurs, flights shall be
made both into and with the wind to minimize the effects of
1.1 This practice covers uniform procedures for determining
wind velocity on ground speed. Flights shall be made parallel
and reporting application rates and distribution patterns from
to or within 20° of the direction of the wind to minimize errors
agricultural aircraft. This practice should not be used for
due to crosswinds. These restrictions do not apply to the output
making biological performance tests.
rate tests.
1.2 The procedures covered deal with both fixed and rotary-
wing aircraft equipped with either liquid or dry material
4. Procedure
distribution systems.
4.1 A complete procedure shall consist of five parts:
1.3 This standard does not purport to address all of the
4.1.1 Determination of the output rate from the aircraft
safety concerns, if any, associated with its use. It is the
system.
responsibility of the user of this standard to establish appro-
4.1.2 Determination of the swath distribution pattern by
priate safety and health practices and determine the applica-
recovery of the applied materials from suitable collectors.
bility of regulatory limitations prior to use.
4.1.3 Determination of usable swath width for field appli-
2. Referenced Documents cations.
4.1.4 Determination of the rate of application of the spray
2.1 ASTM Standards:
mixture or dry material, and
E 726 Test Method for Particle Size Distribution of Granu-
4.1.5 Determination of the uniformity of distribution of
lar Carriers and Granular Pesticides
several swaths.
2.2 ASAE Standard:
4.2 Output Rate Determination:
ASAE S327.1 Terminology and Definitions for Agricultural
4.2.1 Liquid Materials—Determine the output rate by the
Chemical Application
amount of liquid discharged from the tank for a measured time
3. Test Conditions interval while the aircraft is in flight under normal conditions.
The time interval shall be sufficient to permit accurate mea-
3.1 The physical characteristics of the liquid or dry material
surement of liquid discharged and to minimize errors due to
have an effect on the application rate and the distribution
turning the system on and off. Run the system for at least 30 s
patterns. If inert test solutions for materials are substituted for
and measure to the nearest 0.5 s. Measure the amount of liquid
the materials to be applied, they shall have physical character-
used by either refilling the tank to the initial level or by
istics similar to those of the material to be applied. If toxic
measuring the amount remaining in the tank and subtracting
materials are used in the tests, all safety precautions prescribed
from the initial amount. Measurement precision shall be 62%
by the manufacturer and governmental authority for handling,
of the amount discharged in the test. If the liquid dispersal
loading, application, and disposal of toxic materials shall be
system can be operated with the aircraft stationary, the test can
observed.
be accomplished without actually flying the aircraft. Report
3.2 Pattern tests shall be conducted, with wind speeds not
output rate in litres per minute (gallons per minute), and note
exceeding 16 km/h (10 mph), measured 2.5 m (8.2 ft) above
the nozzle (boom) pressure.
4.2.2 Dry Materials—If venturi distributors are used, deter-
This practice is under the jurisdiction of ASTM Committee E-35 on Pesticides
mine the output rate by measuring the amount of material
and is the direct responsibility of Subcommittee E35.22 on Pesticide Formulations
discharged from the hopper over a given time interval while the
and Applications Systems.
Current edition approved March 15, 1991. Published May 1991. Originally
aircraft is in flight under normal conditions. Precision of
published as E 642 – 78. Last previous edition E 642 – 86.
measurement of time and materials as specified in 4.2.1 shall
Annual Book of ASTM Standards, Vol 11.05.
apply here. Run tests with the aircraft hopper filled to at least
Available from American Society of Agricultural Engineers, 2950 Niles Rd., St.
Joseph, MI 49085.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
E 642
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.
4.3.4 Dry Material Test Procedure and Collectors:
4.3 Swath Distribution Pattern Test:
4.3.4.1 Granular materials are normally tested by capturing
4.3.1 Conduct this test by flying the aircraft over the center
samples of the swath in buckets or collectors that are high
of a collection line placed at a right angle to the line of flight.
enough to prevent the particles bouncing into or out of the
The collection line may be placed on the land surface or crop
containers. Collect dust or other small particles on greased
height (or any other height consistent with the purpose of the
boards or other sticky surfaces, or in shallow pans. Weigh or
test), and shall permit collection of a representative sample of
count the material collected in these devices, or dissolve in a
the distribution pattern for the dispersed material. Fly the
solution for analysis as appropriate.
aircraft at a height suited to the type of material applied and the
4.3.4.2 The area of the top opening of the collectors shall be
purpose of the application. The airspeed shall be that for the
2 2
0.1 m (1 ft ) or larger, to provide a representative sample of
intended application and the flight shall be level and straight.
the deposit. Spacing of the collectors along the swath shall not
Extend the collection line at least 3 m (10 ft) beyond the ends
exceed1m(3 ft).
of the pattern being tested. Measure ambient temperature,
4.4 Sample Analysis and Conversion of Swath Distribution
humidity, and wind speed and direction (with respect to the line
Pattern Data:
of flight) at 1 to3m(3to10ft) above the land surface or crop
4.4.1 Spray Pattern Test:
canopy. Note the height of flight and the airspeed.
4.4.1.1 For quantifying spray deposits using tracer materi-
4.3.2 Turn on the distribution equipment in the aircraft at
als, any type of sample analysis may be used that is compatible
least 100 m (300 ft) prior to crossing the collection line, and
with the spray tracer. Examples are photoelectric colorimetry,
continue operating it the same distance beyond. Run three
absorption or emission spectroscopy, and liquid or gas chro-
replications of each test. Make each replication with a separate
matography, where the sensitivity of the analysis shall be at
single pass of the aircraft. Note the direction of flight with
least 2 ppm. After a collector is washed in accordance with
respect to wind direction.
4.3.3, the concentration of tracer may be determined by use of
4.3.3 Spray Test Procedure and Target Collectors:
a standard calibration curve developed for the tracer and the
4.3.3.1 An inert chemical or dye tracer material may be
analytical method employed. The rate of spray deposit in litres
added to the contents of the spray tank, or the active chemical
per hectare (gallons per acre) may then be determined for each
may be used as a tracer for the spray pattern tests. If inert
location across the collection line as follows:
materials are used, include suitable amounts of emulsifier,
D 5 ~K 3 V 3 C !/~C 3 A! (1)
spreader-stickers, and other solvents and carriers to closely t t s
simulate the material to be applied.
where:
4.3.3.2 The spray collection line may be composed of
D 5 deposit rate, L/ha (gal/acre),
discrete targets or a narrow continuous surface. Quantitative
K 5 constant, 10 (or 1657),
2 2
analysis of the spray deposited on the target collector(s) may be
A 5 collector area, cm (in. ),
accomplished by electronic scanning or by washing tracer
5 volume of solvent used to wash tracer from target,
t
material from the collector surface(s).
mL,
4.3.3.3 If the pattern is determined from the amount of C 5 concentration of tracer washed from collector, mg/L,
t
tracer material recovered from the line, the surface of the and
C 5 concentration of collector in original spray solution,
collector(s) shall permit all or a constant percentage of the
s
mg/L.
tracer to be removed by washing. If the tracer used degrades
due to exposure to sunlight, age, or other factors, the results 4.4.1.2 Quantifying spray deposits using image scanning of
should be corrected to compensate for the degradation. If discrete or continuous sample surfaces shall utilize sufficient
discrete targets are used, they may be flat sheets, or have raised size classes, preferably at least 20, to accurately define the
edges to facilitate washing. The exposed flat surface (exclusive droplet size distribution. A droplet size versus spread factor
2 2
of raised edges) shall have an area of at least 50 cm (7.8 in. ). function covering the droplet size range encountered under test
Spacing of descrete targets across the swath shall not exceed 1 conditions (temperature and relative humidity) shall be devel-
m (3.3 ft). oped for the sample surface material and test liquid and used in
calculating the deposit volume per unit of area.
4.3.3.4 For samples that are electronically scanned to mea-
4.4.2 Dry Material Test—If the dry material deposited in the
sure deposition on the sample surface based on droplet size and
collection device at each location across the line of collectors
numbers, an appropriate area must be scanned to obtain a true
is weighed, the deposit rate may be determined in kg/ha
representation of the droplet-size distribution in the sample.
(lb/acre) as follows:
4.3.3.5 Qualitative Spray Distribution Pattern
Measurement—A qualitative measure of the distribution pat-
D 5 ~K 3 W!/A (2)
tern may be used to diagnose and correct distribution system
where:
deficiencies (plugged or worn nozzles, improper size nozzles,
D 5 deposit rate, kg/ha (lb/acre),
system leaks, improperly placed nozzles, and so forth). Quali-
K 5 constant, 10 (13 829),
tative distribution pattern measurement techniques may em-
W 5 weight collected, g, and
ploy discrete sample targets or a continuous collector placed
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
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E 642
2 2
ranging from one sampling interval width to the total width of
A 5 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
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
4.6 Rate of Application—Calculate the overall rate of ap-
outlined in 4.4.1 may be used for analysis of dust deposits if the
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
where:
the line of collectors.
R 5 rate of application, L/ha or kg/ha (gal/acre or lb/acre),
4.5 Plotting the Distribution Curve and Evaluating Swath
Q 5 output rate, L/min or kg/min (gpm or lb/min),
Widths—Data for each test replication from 4.4.1 or 4.4.2 will
K 5 constant, 600 (495),
be plotted with the rate of deposit on the ordinate and the
V 5 velocity over ground, km/h (mph), and
location of deposit with respect to the aircraft center line on the
S 5 usable swath width, m (ft).
abscissa. This data, or the resulting plot, or both, will be used
4.7 Uniformity of Distribution—Use the coefficient of varia-
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
plotted in 4.5 or from actual flight tests using a sufficiently long
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 field distribution by accumulating the
effective swath width may be determined as the distance
collector readings that result when swaths are combined, using
between points on either side of the pattern where the rate of the effective swath width. Use individual replicates of the
deposit equals one half of the maximum rate for the pattern. If
swath p
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