ASTM E680-79(2005)
(Test Method)Standard Test Method for Drop Weight Impact Sensitivity Of Solid-Phase Hazardous Materials
Standard Test Method for Drop Weight Impact Sensitivity Of Solid-Phase Hazardous Materials
SIGNIFICANCE AND USE
This method does not require an overall rigid standardization of the apparatus. Samples are tested either unconfined or confined in confinement cups. For confined tests, some of the important cup parameters, such as cup material, cup wall thickness, and fit between the cup and the striking pin, are standardized. Data generated from unconfined and confined tests will not, in general, exhibit the same relative scale of sensitivities, and must be identified as confined or unconfined data and compared separately.
This method applies to all testing where the intent is to establish a relative sensitivity scale for hazardous materials. It is not intended to prohibit testing process-thickness samples nor prohibit the use of other than standard tool masses and striking diameters to generate data for special purposes or for in-house comparisons. In addition, the method is not intended to restrict the generation of results at other than the H50 point as may be desirable for hazard analysis techniques.
The normalized data will serve as a measure of the relative sensitivities of hazardous materials at the 50 % probability of reaction level. The normalized H50 values can also be used in conjunction with additional data relating to other probability of reaction levels (not a part of this method) to assess hazards associated with the manufacture, transportation, storage, and use of hazardous materials.
SCOPE
1.1 This test method, is designed to determine the relative sensitivities of solid-phase hazardous materials to drop weight impact stimulus. For liquid-phase materials refer to Method D 2540.
This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety problems associated with its use. It is the responsibility of whoever uses this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: E680 – 79 (Reapproved 2005)
Standard Test Method for
Drop Weight Impact Sensitivity of Solid-Phase Hazardous
Materials
This standard is issued under the fixed designation E680; 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.
INTRODUCTION
This test method is one of several test methods being developed by ASTM Committee E27 on
Hazard Potential of Chemicals. This test method is to be used in conjunction with other tests to
characterize the hazard potential of chemicals.
1. Scope standard sample thickness is prescribed for all tests. In
,
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addition, procedures for sample preparation and treatment, as
1.1 This test method is designed to determine the relative
well as procedures for detecting reactions through the use of
sensitivities of solid-phase hazardous materials to drop weight
the human senses, are outlined.
impact stimulus. For liquid-phase materials refer to Test
3.2 Drop-weight impact tests are to be performed using the
Method D2540.
,
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well-known Bruceton up-and-down method.
1.2 This standard may involve hazardous materials, opera-
3.3 Outlined is a method for normalizing data generated on
tions, and equipment. This standard does not purport to
different impact apparatus.
address all of the safety problems associated with its use. It is
the responsibility of whoever uses this standard to consult and
4. Significance and Use
establish appropriate safety and health practices and deter-
4.1 This test method does not require an overall rigid
mine the applicability of regulatory limitations prior to use.
standardization of the apparatus. Samples are tested either
2. Referenced Documents unconfinedorconfinedinconfinementcups.Forconfinedtests,
some of the important cup parameters, such as cup material,
2.1 ASTM Standards:
cupwallthickness,andfitbetweenthecupandthestrikingpin,
D2540 Test Method for Drop-Weight Sensitivity of Liquid
arestandardized.Datageneratedfromunconfinedandconfined
Monopropellants
tests will not, in general, exhibit the same relative scale of
3. Summary of Test Method
sensitivities, and must be identified as confined or unconfined
data and compared separately.
3.1 Restrictions are placed upon the ranges of impact tool
4.2 This test method applies to all testing where the intent is
masses and striking surface diameters that may be used, and a
to establish a relative sensitivity scale for hazardous materials.
It is not intended to prohibit testing process-thickness samples
This test method is under the jurisdiction ofASTM Committee E27 on Hazard
nor prohibit the use of other than standard tool masses and
Potential of Chemicals and is the direct responsibility of Subcommittee E27.02 on
striking diameters to generate data for special purposes or for
Thermal Stability and Condensed Phases.
Current edition approved March 1, 2005. Published April 2005. Originally
in-house comparisons. In addition, the test method is not
approved in 1979. Last previous edition approved in 1999 as E680 – 79 (1999).
DOI: 10.1520/E0680-79R05.
This test method is a modification of and contains concepts proposed by
Hercules, Inc. personnel at Allegheny Ballistics Laboratory. The method was Becker, K. R., and Watson, R. W., “A Critique for Drop Weight Impact
outlined by personnel of Pittsburgh Mining and Safety Research Center, Bureau of Testing,” Proceedings of the Conference on the Standardization of Safety and
Mines, Pittsburgh, Pa. For additional information see footnote 3. Performance Tests for Energetic Materials, Vol 1, September 1977, pp. 415–430.
Smith, D., and Richardson, R. H., “Interpretation of Impact Sensitivity Test Publication ARLCD-SP-77004, U. S. Army Armament Research and Development
Data,” Pyrodynamics, PYDYA, Vol 6, 1968, pp. 159–178. Command, Dover, N.J.
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For referenced ASTM standards, visit the ASTM website, www.astm.org, or Dixon, W. J., and Massey, F. J. Jr., Introduction to Statistical Analysis,
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM McGraw-Hill Book Co., Inc., 1957, pp. 319–327.
Standards volume information, refer to the standard’s Document Summary page on Statistical Research Group, Princeton University, “Statistical Analysis for a
the ASTM website. New Procedure in Sensitivity Experiments,” AMP Report No. 101.1R, SRG-P, No.
Withdrawn. The last approved version of this historical standard is referenced 40, Submitted to Applied Mathematics Panel, National Defense Research Commit-
on www.astm.org. tee, July 1944, p. 58.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E680 – 79 (2005)
intended to restrict the generation of results at other than the 6.5 The diameter of the striking surface of the intermediate
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H point as may be desirable for hazard analysis techniques. weight shall be 9.52 to 19.05 mm ( ⁄8 to ⁄4 in.). These limits
4.3 The normalized data will serve as a measure of the were determined simply on the basis that data have been
relative sensitivities of hazardous materials at the 50 % prob- successfully normalized for tool diameters in this range.
abilityofreactionlevel.Thenormalized H valuescanalsobe
50 6.6 The finish on the striking surface of the intermediate
used in conjunction with additional data relating to other
weight and of the anvil, though not highly critical in tests with
probability of reaction levels (not a part of this test method) to
solid explosives, should be a No. 8 grind (8 µin.) or finer. If
assess hazards associated with the manufacture, transportation,
substantially different surface finishes are used, the data
storage, and use of hazardous materials.
obtained should be accompanied by a footnote specifying the
finish used.
5. Definitions
6.7 Inconfinedtests,theconfinementcupshallbefabricated
5.1 H value—a drop height with a 50 % probability of
50 from Type 302 stainless steel. The cup base thickness shall
reaction, as determined experimentally by the Bruceton up-
range from 0.13 to 0.15 mm (0.005 to 0.006 in.). The outer
and-down method.
periphery of the striking pin shall be in contact with a small
5.2 impact tools—thedropweight,intermediateweight,and
portion of the arc joining the side and bottom of the cup.
anvil.
Although this permits greater energy losses in working the
5.3 drop weight—that weight which is raised to a selected
metal inside the cup than if the whole striking surface engaged
height and released. This weight does not impact the sample
only the flat portion of the metal in the base of the cup, it does
directly; rather it strikes another stationary weight that is in
ensure better confinement with less flow of test material up the
contact with the sample.
sides of the striking pin and cup. A typical confinement cup is
5.4 intermediate weight—the stationary weight in contact
showninFig.1.This,togetherwiththestrikingpindimensions
with the sample.
shown in Fig. 2, provide some insight on a suitable mating
5.5 anvil—the smooth, hardened surface upon which the
between the striking pin and cup.
test sample or cup containing the sample rests.
6.8 Experience has shown that an appreciable difference in
5.6 unconfined test—a test in which the test sample is
the behavior of the apparatus can result from the manner in
placed directly upon the anvil with no lateral confinement.
which it is mounted. Thus, the machine should be mounted on,
5.7 confined test—a test in which the test sample is con-
and firmly attached to, a solid concrete foundation, preferably
tained within a confinement cup (sample container), and the
anchored to the foundation of a building (see Test Method
confinement cup is then placed upon the anvil.
D2540).
5.8 confinement cup—the metal sample container used in
6.9 Fig. 3 illustrates a typical impact apparatus, and Figs. 4
confined tests.
and 1 are detailed drawings of a drop weight, an intermediate
5.9 guide bushing—the steel bushing that surrounds, aligns,
weight, and a confinement cup. Helpful notes on construction
and holds the stationary intermediate weight in place.
of the tools are found in the Appendix. These tools and
5.10 guide system—the rails, wires, and shaft that guide the
apparatus are in use at the U. S. Bureau of Mines, Bruceton,
drop weight during its fall.
Pa., but are not necessarily the only acceptable designs. All
5.11 striking surface—the hardened, smooth, circular bot-
designs, however, should incorporate a device that captures the
tom surface of the intermediate tool that is in contact with the
drop weight after it rebounds to prevent further interactions
test sample.
with the intermediate weight.
5.12 impact apparatus or machine—the total apparatus
including the foundation parts, guide rails, electromagnet lift,
winch, and tools.
6. Apparatus
6.1 A complete impact apparatus is the specialized appara-
tus necessary for this test method.
6.2 The masses of the drop weight ( m ) and intermediate
weight (m ) should, preferably, be equal. However, the
intermediate weight mass may be less than that of the drop
weight mass so long as the mass ratio m /m is 0.6 or greater.
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This ensures that the force-time stimulus a test sample is
subjected to will be nonoscillatory in nature, and ensures that
the transfer of energy from the drop weight to the intermediate
weight does not vary significantly.
6.3 The mass of the drop weight should be between 1.0 to
3.5 kg.
6.4 The hardness of all tooling surfaces involved in the
impact (drop weight, intermediate weight, and anvil) should
FIG. 1 Confinement Cup Used as a Sample Container in Confined
have a Rockwell C Hardness of 55 to 59 HRC. Tests
E680 – 79 (2005)
FIG. 2 Intermediate Weight Assembly
7. Test Sample
7.1 Sample thickness must be the same for all tests. This is
achieved by using a constant volume per unit area sample
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spreaduniformlyoverthatarea.Thestandardis31.5mm /cm .
This provides a distributed thickness of 0.315 mm (12.4 mils)
and ensures the same energy input per unit mass of a given test
material no matter what the diameter of the striking surface
area is. Thus, for a sample diameter of 12.7 mm (0.50 in.), 40
mm of sample volume would be used. Proportionately larger
or smaller sample volumes, varying in direct proportion to the
sample, may be used so long as the sample volume per unit
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FIG. 3 Bureau of Mines Impact Apparatus
area is 31.5 mm /cm . Errors in sample volume may be
610 %, and sample measuring spoons having the appropriate
volume can be machined or drilled for this purpose. In cases test where the sample is spread directly upon the anvil, use
where it is desirable to test process thickness samples that about a 0.33-mm (13-mil) thick template made from plastic,
differ from the standard, simply indicate the thickness used, metal,ortapehavingacircularholecutinit.Placethetemplate
especially if the H values appear in the same tables together on the anvil, pile the sample in the hole, and scrape level with
with H values obtained using standard thickness samples. a spatula or straight edge. The hole diameter should, in all
7.1.1 In some cases, the sample consistency may prohibit cases, be somewhat larger than the tool contact surface
thesamplefrombeingmeasuredinameasuringspoon.Inthese diameter. Leave the template in place during the impact trial.
instances, the proper sample size can be determined by its The larger size will make it easy to miss striking the periphery
mass;M= rV,where Visthepropervolumeforagivensample of the template hole during impact.The template also serves as
area, andr is the loose-packing density of the sample. The an excellent means for keeping the sample inbounds. The
density may have to be determined if it has not been specified. recommended template hole for a 12.7-mm ( ⁄2-in.) diameter
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7.2 Specifications of sample diameters to be used in con- tool is 15.9 mm ( ⁄8 in.), but it may be 19.1 mm ( ⁄4 in.) or
junction with different diameter tools are as follows: ( a)in larger, as long as a proportionally larger sample is used. Here,
confined tests, specifically, a test where the sample is confined it is important to remember that the sample volume or mass
in a cylindrical cup, the sample diameter will be the same as used to obtain constant-thickness samples is based upon the
the inside diameter of the cup. Hence, calculate a sample template diameter, not the tool diameter.
volume or mass based upon the inside diameter of the 7.2.1 Innocaseshouldthesamplediameterbelessthanthat
confinement cup, and (b) for unconfined tests, specifically, a of the tool. The normalization method cannot be applied if this
E680 – 79 (2005)
easily be detected using a plumb line, since a 0.25-deg
misalignment amounts to a 13-mm displacement over a
3000-mm length.
8.1.2.1 Align the bottom face (striking surface) of the
intermediate weight and the top surface of the anvil. These
surfaces must be both plane and parallel. A convenient way to
check this is with Prussian blue dye. Place a small amount of
the dye on a piece of paper and insert the paper between the
intermediate tool striking surface and anvil. By hand lower the
intermediate tool onto the area of the paper containing the dye.
Lift the intermediate tool and insert a clean piece of paper.
Lower and raise the tool a number of times on different areas
of the clean paper, making many different imprints. Be careful
nottomakeajudgmentsolelyonthebasisofthefirstorsecond
imprint, since an excess of dye might smear and cover up
defects. If the two surfaces are not parallel, a portion of one
sideofthecirclewillbemissing.Aconvextoolstrikingsurface
willproduceacirclehavingadiameterlessthanthatofthetool
striking surface, whereas a concave tool will produce a normal
diameter circle with the bare spot centrally located. If any of
these defects or others are noted, take proper steps to eliminate
them.
8.1.3 Cleanliness—Keepallsurfacesoftheweights,guides,
and interior of the guide bushing reasonably clean at all times.
Clean especially the intermediate tool striking surface and top
of the anvil for each trial. All traces of explosive or residue
FIG. 4 Drop Weight Assembly
fromreactionsmustberemovedwithatissuewetwithacetone,
andthenwipedwithclean,drytissue.Cleanthebottomsurface
of the drop weight and top surface of the intermediate weight
is the case. Furthermore, the normalization method cannot be
several times during an up-and-down test.
applied to mixed data from confined and unconfined tests. It is
9. Procedures
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