ASTM E680-79(1999)
(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
SCOPE
1.1 This test method 2,3 is designed to determine the relative sensitivities of solid-phase hazardous materials to drop weight impact stimulus. For liquid-phase materials refer to Method D2540.
1.2 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.
General Information
Relations
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: E 680 – 79 (Reapproved 1999)
Standard Test Method for
Drop Weight Impact Sensitivity Of Solid-Phase Hazardous
Materials
This standard is issued under the fixed designation E 680; 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.
INTRODUCTION
This method is one of several methods being developed by ASTM Committee E-27 on Hazard
Potential of Chemicals. This method is to be used in conjunction with other tests to characterize the
hazard potential of chemicals.
1. Scope well as procedures for detecting reactions through the use of
,
2 3
the human senses, are outlined.
1.1 This test method is designed to determine the relative
3.2 Drop-weight impact tests are to be performed using the
sensitivities of solid-phase hazardous materials to drop weight
,
6 7
well-known Bruceton up-and-down method.
impact stimulus. For liquid-phase materials refer to Method
3.3 Outlined is a method for normalizing data generated on
D 2540.
different impact apparatus.
1.2 This standard may involve hazardous materials, opera-
tions, and equipment. This standard does not purport to
4. Significance and Use
address all of the safety problems associated with its use. It is
4.1 This method does not require an overall rigid standard-
the responsibility of whoever uses this standard to consult and
ization of the apparatus. Samples are tested either unconfined
establish appropriate safety and health practices and deter-
or confined in confinement cups. For confined tests, some of
mine the applicability of regulatory limitations prior to use.
the important cup parameters, such as cup material, cup wall
2. Referenced Documents thickness, and fit between the cup and the striking pin, are
standardized. Data generated from unconfined and confined
2.1 ASTM Standards:
tests will not, in general, exhibit the same relative scale of
D 2540 Test Method for Drop Weight Sensitivity of Liquid
sensitivities, and must be identified as confined or unconfined
Monopropellants
data and compared separately.
3. Summary of Method
4.2 This method applies to all testing where the intent is to
establish a relative sensitivity scale for hazardous materials. It
3.1 Restrictions are placed upon the ranges of impact tool
is not intended to prohibit testing process-thickness samples
masses and striking surface diameters that may be used, and a
nor prohibit the use of other than standard tool masses and
standard sample thickness is prescribed for all tests. In
striking diameters to generate data for special purposes or for
addition, procedures for sample preparation and treatment, as
in-house comparisons. In addition, the method is not intended
to restrict the generation of results at other than the H point
This method is under the jurisdiction of ASTM Committee E-27 on Hazard
as may be desirable for hazard analysis techniques.
Potential of Chemicalsand is the direct responsibility of Subcommittee E27.02on
4.3 The normalized data will serve as a measure of the
Thermal Stability.
relative sensitivities of hazardous materials at the 50 % prob-
Current edition approved Feb. 23, 1979. Published April 1979.
ability of reaction level.The normalized H values can also be
This method is a modification of and contains concepts proposed by Hercules,
Inc. personnel at Allegheny Ballistics Laboratory. The method was outlined by
used in conjunction with additional data relating to other
personnel of Pittsburgh Mining and Safety Research Center, Bureau of Mines,
Pittsburgh, Pa. For additional information see footnote 3.
Smith, D., and Richardson, R. H., “Interpretation of Impact Sensitivity Test
Data,” Pyrodynamics, PYDYA, Vol 6, 1968, pp. 159–178.
4 6
Annual Book of ASTM Standards, Vol 15.03. Dixon, W. J., and Massey, F. J. Jr., Introduction to Statistical Analysis,
Becker, K. R., and Watson, R. W., “A Critique for Drop Weight Impact McGraw-Hill Book Co., Inc., 1957, pp. 319–327.
Testing,” Proceedings of the Conference on the Standardization of Safety and Statistical Research Group, Princeton University, “Statistical Analysis for a
Performance Tests for Energetic Materials, Vol 1, September 1977, pp. 415–430. New Procedure in Sensitivity Experiments,” AMP Report No. 101.1R, SRG-P, No.
Publication ARLCD-SP-77004, U. S. Army Armament Research and Development 40, Submitted to Applied Mathematics Panel, National Defense Research Commit-
Command, Dover, N.J. tee, July 1944, 58 pp.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E 680
probability of reaction levels (not a part of this method) to substantially different surface finishes are used, the data
assess hazards associated with the manufacture, transportation, obtained should be accompanied by a footnote specifying the
storage, and use of hazardous materials. finish used.
6.7 Inconfinedtests,theconfinementcupshallbefabricated
5. Definitions
from Type 302 stainless steel. The cup base thickness shall
5.1 H value—a drop height with a 50 % probability of
range from 0.13 to 0.15 mm (0.005 to 0.006 in.). The outer
reaction, as determined experimentally by the Bruceton up-
periphery of the striking pin shall be in contact with a small
and-down method.
portion of the arc joining the side and bottom of the cup.
5.2 impact tools—thedropweight,intermediateweight,and
Although this permits greater energy losses in working the
anvil.
metal inside the cup than if the whole striking surface engaged
5.3 drop weight—that weight which is raised to a selected
only the flat portion of the metal in the base of the cup, it does
height and released. This weight does not impact the sample
ensure better confinement with less flow of test material up the
directly; rather it strikes another stationary weight that is in
sides of the striking pin and cup. A typical confinement cup is
contact with the sample.
showninFig.1.This,togetherwiththestrikingpindimensions
5.4 intermediate weight—the stationary weight in contact
shown in Fig. 2, provide some insight on a suitable mating
with the sample. between the striking pin and cup.
5.5 anvil—the smooth, hardened surface upon which the
6.8 Experience has shown that an appreciable difference in
test sample or cup containing the sample rests. the behavior of the apparatus can result from the manner in
5.6 unconfined test—a test in which the test sample is
which it is mounted. Thus, the machine should be mounted on,
placed directly upon the anvil with no lateral confinement. and firmly attached to, a solid concrete foundation, preferably
5.7 confined test—a test in which the test sample is con-
anchored to the foundation of a building (see Method D 2540).
tained within a confinement cup (sample container), and the 6.9 Fig. 3 illustrates a typical impact apparatus, and Figs. 4
confinement cup is then placed upon the anvil.
and 1 are detailed drawings of a drop weight, an intermediate
5.8 confinement cup—the metal sample container used in
weight, and a confinement cup. Helpful notes on construction
confined tests.
of the tools are found in the Appendix. These tools and
5.9 guide bushing—the steel bushing that surrounds, aligns,
apparatus are in use at the U. S. Bureau of Mines, Bruceton,
and holds the stationary intermediate weight in place.
Pa., but are not necessarily the only acceptable designs. All
5.10 guide system—the rails, wires, and shaft that guide the
designs, however, should incorporate a device that captures the
drop weight during its fall.
drop weight after it rebounds to prevent further interactions
5.11 striking surface—the hardened, smooth, circular bot-
with the intermediate weight.
tom surface of the intermediate tool that is in contact with the
test sample. 7. Test Sample
5.12 impact apparatus or machine—the total apparatus
7.1 Sample thickness must be the same for all tests. This is
including the foundation parts, guide rails, electromagnet lift,
achieved by using a constant volume per unit area sample
3 2
winch, and tools.
spreaduniformlyoverthatarea.Thestandardis31.5mm /cm .
This provides a distributed thickness of 0.315 mm (12.4 mils)
6. Apparatus
and ensures the same energy input per unit mass of a given test
6.1 A complete impact apparatus is the specialized appara-
material no matter what the diameter of the striking surface
tus necessary for this method.
area is. Thus, for a sample diameter of 12.7 mm (0.50 in.), 40
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.
2 1
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
have a Rockwell C Hardness of 55 to 59 HRC.
6.5 The diameter of the striking surface of the intermediate
3 3
weight shall be 9.52 to 19.05 mm ( ⁄8to ⁄4 in.). These limits
were determined simply on the basis that data have been
successfully normalized for tool diameters in this range.
6.6 The finish on the striking surface of the intermediate
weight and of the anvil, though not highly critical in tests with
FIG. 1 Confinement Cup Used as a Sample Container in Confined
solid explosives, should be a No. 8 grind (8 µin.) or finer. If Tests
E 680
FIG. 2 Intermediate Weight Assembly
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
3 2
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
where it is desirable to test process thickness samples that
differ from the standard, simply indicate the thickness used,
especially if the H values appear in the same tables together
with H values obtained using standard thickness samples.
7.1.1 In some cases, the sample consistency may prohibit
thesamplefrombeingmeasuredinameasuringspoon.Inthese
FIG. 3 Bureau of Mines Impact Apparatus
instances, the proper sample size can be determined by its
mass; M5rV, where V is the proper volume for a given
sample area, andr is the loose-packing density of the sample. diameter. Leave the template in place during the impact trial.
The density may have to be determined if it has not been The larger size will make it easy to miss striking the periphery
specified. of the template hole during impact.The template also serves as
7.2 Specifications of sample diameters to be used in con- an excellent means for keeping the sample inbounds. The
junction with different diameter tools are as follows: ( a)in recommended template hole for a 12.7-mm ( ⁄2-in.) diameter
5 3
confined tests, specifically, a test where the sample is confined tool is 15.9 mm ( ⁄8 in.), but it may be 19.1 mm ( ⁄4 in.) or
in a cylindrical cup, the sample diameter will be the same as larger, as long as a proportionally larger sample is used. Here,
the inside diameter of the cup. Hence, calculate a sample it is important to remember that the sample volume or mass
volume or mass based upon the inside diameter of the used to obtain constant-thickness samples is based upon the
confinement cup, and (b) for unconfined tests, specifically, a template diameter, not the tool diameter.
test where the sample is spread directly upon the anvil, use 7.2.1 Innocaseshouldthesamplediameterbelessthanthat
about a 0.33-mm (13-mil) thick template made from plastic, of the tool. The normalization method cannot be applied if this
metal,ortapehavingacircularholecutinit.Placethetemplate is the case. Furthermore, the normalization method cannot be
on the anvil, pile the sample in the hole, and scrape level with applied to mixed data from confined and unconfined tests. It is
a spatula or straight edge. The hole diameter should, in all generally applicable in the unconfined case. Information is
cases, be somewhat larger than the tool contact surface limited on applicability to the confined case. However, it is
E 680
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
fromreactionsmustberemovedwithatissuewetwithacetone,
andthenwipedwithclean,drytissue.Cleanthebottomsurface
of the drop weight and top surface of the intermediate weight
several times during an up-and-down test.
9. Procedures
FIG. 4 Drop Weight Assembly
9.1 Avoid testing hygroscopic materials under high humid-
ity conditions, if climate control is not available. Sample
believed that data from confined trials could be normalized
conditioningandcertaintestprocedurescanbeimplementedto
provided the confinement parameters are reasonably alike. The
minimize humidity effects.
important cup parameters that were standardized were given in
9.2 For materials that have been stored under unknown or
6.7.
high humidity conditions, vacuum dry the samples for2hat
8. Preparation of Apparatus
90°C. For test samples thermally sensitive to 90°C vacuum dry
8.1 Inspection
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.