ASTM F1738-96(2007)
(Test Method)Standard Test Method for Determination of Deposition of Aerially Applied Oil Spill Dispersants
Standard Test Method for Determination of Deposition of Aerially Applied Oil Spill Dispersants
SIGNIFICANCE AND USE
The deposition of an aerially applied dispersant is defined as the amount of an aerially applied dispersant that contacts the surface; whereas, application dosage (frequently referred to as application rate) is the amount of material that is released per unit area by the delivery system. The units of deposition are litres per hectare or U.S. gallons per acre. The deposition may differ from the application dosage (volume of material per unit area) for many reasons, such as, the effects of wind on the spray and the evaporation of the dispersant after it has been released from the aircraft.
This test method describes the measurement of the ability of a spray system to deposit a dispersant on oil. It is not intended that this test method be used at the time of a spill. These techniques are intended to determine the equipment performance during the development of new systems and after the repair or significant modification of a system.
The data obtained from the use of this test method can be directly related to the deposition of dispersant on an oil slick, and thus can serve to determine both the dispersant deposition and the droplet size.
Dispersant deposition and droplet size data can be used as a technical basis for the optimization of dispersant application equipment and its use.
SCOPE
1.1 This test method covers the measurement of the deposition of an aerially applied dispersant on the surface of the ground or water. The test method of obtaining these measurements is described, and the analysis of the results, in terms of dispersant use, is considered. There are a number of techniques that have been developed, and this test method outlines their application. These measurements can be used to confirm or verify the specifications of a given equipment set, its proper functioning, and use.
1.2 This test method is applicable to systems used with helicopters or airplanes.
1.3 This test method is one of four related to dispersant application systems. Guide F 1413 covers design, Practice F 1460 covers calibration, Test Method F 1738 covers deposition, and Guide F 1737 covers the use of the systems. Familiarity with all four standards is recommended.
1.4 There are some exposure and occupational health concerns regarding the methods described. These are not discussed in this test method since they are a function of dispersant formulation. Anyone undertaking such experiments should consult the occupational health experts of the dispersant manufacturer regarding the precautions to be used.
1.5 The values stated in SI units are to be regarded as the standard.
1.6 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
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Standards Content (Sample)
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Designation:F1738–96(Reapproved 2007)
Standard Test Method for
Determination of Deposition of Aerially Applied Oil Spill
Dispersants
This standard is issued under the fixed designation F1738; 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 F1413 Guide for Oil Spill Dispersant Application Equip-
ment: Boom and Nozzle Systems
1.1 This test method covers the measurement of the depo-
F1460 Practice for Calibrating Oil Spill Dispersant Appli-
sition of an aerially applied dispersant on the surface of the
cation Equipment Boom and Nozzle Systems
ground or water. The test method of obtaining these measure-
F1737 Guide for Use of Oil Spill Dispersant Application
ments is described, and the analysis of the results, in terms of
Equipment During Spill Response: Boom and Nozzle
dispersant use, is considered.There are a number of techniques
Systems
that have been developed, and this test method outlines their
application. These measurements can be used to confirm or
3. Significance and Use
verify the specifications of a given equipment set, its proper
3.1 The deposition of an aerially applied dispersant is
functioning, and use.
defined as the amount of an aerially applied dispersant that
1.2 This test method is applicable to systems used with
contacts the surface; whereas, application dosage (frequently
helicopters or airplanes.
referred to as application rate) is the amount of material that is
1.3 This test method is one of four related to dispersant
released per unit area by the delivery system. The units of
application systems. Guide F1413 covers design, Practice
deposition are litres per hectare or U.S. gallons per acre. The
F1460 covers calibration, Test Method F1738 covers deposi-
deposition may differ from the application dosage (volume of
tion, and Guide F1737 covers the use of the systems. Famil-
material per unit area) for many reasons, such as, the effects of
iarity with all four standards is recommended.
wind on the spray and the evaporation of the dispersant after it
1.4 There are some exposure and occupational health con-
has been released from the aircraft.
cernsregardingthemethodsdescribed.Thesearenotdiscussed
3.2 This test method describes the measurement of the
in this test method since they are a function of dispersant
ability of a spray system to deposit a dispersant on oil. It is not
formulation. Anyone undertaking such experiments should
intended that this test method be used at the time of a spill.
consult the occupational health experts of the dispersant
These techniques are intended to determine the equipment
manufacturer regarding the precautions to be used.
performance during the development of new systems and after
1.5 The values stated in SI units are to be regarded as the
the repair or significant modification of a system.
standard.
3.3 The data obtained from the use of this test method can
1.6 This standard does not purport to address all of the
be directly related to the deposition of dispersant on an oil
safety concerns, if any, associated with its use. It is the
slick, and thus can serve to determine both the dispersant
responsibility of the user of this standard to establish appro-
deposition and the droplet size.
priate safety and health practices and determine the applica-
3.4 Dispersant deposition and droplet size data can be used
bility of regulatory limitations prior to use.
as a technical basis for the optimization of dispersant applica-
2. Referenced Documents tion equipment and its use.
2.1 ASTM Standards:
4. Apparatus and Materials
4.1 The basic concept is to provide a collection surface on
This test method is under the jurisdiction of ASTM Committee F20 on
which the aerially applied material is deposited.The amount of
Hazardous Substances and Oil Spill Response and is the direct responsibility of
material and the deposition pattern and its droplet size can be
Subcommittee F20.13 on Treatment.
measured using this surface. Several systems and methods
Current edition approved April 1, 2007. Published May 2007. Originally
approved in 1996. Last previous edition approved in 1999 as F1738 – 96 (1999). have been developed, and each has its own advantages and
DOI: 10.1520/F1738-96R07.
disadvantages.
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
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
F1738–96 (2007)
4.2 Thesemeasurementsrequirealarge,flatopenarea(such care must be taken to ensure that the same dilution factors are
as a field or an airport) which is suitable for low-level flying used for both the calibration and material from the sampling
and maneuvering. The location should be away from human dishes, since the measurement instruments are only linear over
habitations or environmentally sensitive areas in order to about an order of magnitude of concentration. From these sets
minimize problems due to noise and drifting spray. of data, the amount of material deposited on the surface in any
4.3 These field programs should be conducted under low- units required, such as litres/hectare (U.S. gal/acre), can be
wind conditions in order to minimize drift. Near-surface calculated.
turbulence due to thermal gradients or atmospheric instability
5.1.2 Metal Troughs—A variation of the sampling dish is a
cancontributetoavariationintheresults.Thesemeasurements
V-shaped metal trough, divided into sections and placed
cannot be carried out in the presence of precipitation or in
perpendicular to the flight path. Each section is about two
heavy concentrations of dust.
metres long with a cross section of about 6 cm. A number of
4.4 All tests are to be conducted with the flight path in an
troughs, connected end-to-end, are used to cover a length of
upwind direction. The upwind direction is chosen to simplify
about25 %greaterthanthetotalspraywidth.Afterasprayrun,
the interpretation of the data and to conform with typical field
the troughs are washed with a solvent, such as methanol or
practice. It may be necessary to alter the flight path slightly for
hexane, and the eluent from each section is collected for
changes in wind direction during the course of an experimental
analysis. The concept is similar to that of the glass dishes, but
program.
this system has the advantage of sampling the total spray
4.5 It is common practice to use a dye, soluble in the
width, and providing an average dose over the discrete section.
dispersant, which will assist in the detection of the dispersant
Onemajoradvantageofthetroughsisthattheyremaininplace
by the analysis system. Oil Red B and Rhodamine WP have
during a number of experimental runs, thus reducing the time
been used at concentrations of 0.1 to 2.0 %. The sensitivity of
between runs. This allows for more runs per day.
current detection systems allows the use of concentrations at
5.1.3 String Measurement—Another method uses a cord or
the 0.1 % level or less.
string that is either stretched across the width of the spray or is
4.6 The area used will become covered with dispersant
supported on a series of stands. Except for very narrow-width
spray, and it is suggested that the area not be used for
application systems, the string is supported about every two
agricultural purposes at least until any evidence of the dispers-
metres by a stand.The dispersant is collected by the string, and
ant or dye is no longer observable. The length of time depends
thustheneededdataareobtained.Sincethecrosssectionofthe
on the weather conditions, especially precipitation that occurs
string is much smaller than that of the Petri dish or trough,
after the spray program has been completed.
more dye may be needed in the sprayed dispersant. The string
is then allowed to dry. The amount of material that the string
5. Deposition Measurement Methods
collected is determined by a fluorometric or colormetric
5.1 These techniques involve the use of a collecting surface
technique. This method measures the relative deposition only,
of known area and the measurement of the amount and
and not the absolute deposition.
character of the dispersant deposited on this area. A variety of
5.1.4 Data Determination—The data collected from these
systems may be used, such as the following:
types of measurements is the same in character. The amount of
5.1.1 GlassPetriDishesorSimilarContainers—Flatdishes
dispersant that reaches the ground is measured as a function of
of known area are placed in a line perpendicular to the flight
the position along the swath of the spray. From this, spray
path, and extending over a distance 25 % greater than the
patterns can be determined and plotted. Data gathered using
expected swath width. Dishes of a diameter of 120 to 140 mm
dishes and the metal troughs can be used to compute the actual
are typically used. There should be about twenty dishes placed
deposition.
across the flight path in order to have
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