1、Designation: E 680 79 (Reapproved 2005)Standard Test Method forDrop Weight Impact Sensitivity Of Solid-Phase HazardousMaterials1This standard is issued under the fixed designation E 680; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisi
2、on, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.INTRODUCTIONThis method is one of several methods being developed by ASTM Committee E-27 on HazardPotential of Ch
3、emicals. This method is to be used in conjunction with other tests to characterize thehazard potential of chemicals.1. Scope1.1 This test method2,3is designed to determine the relativesensitivities of solid-phase hazardous materials to drop weightimpact stimulus. For liquid-phase materials refer to
4、MethodD 2540.1.2 This standard may involve hazardous materials, opera-tions, and equipment. This standard does not purport toaddress all of the safety problems associated with its use. It isthe responsibility of whoever uses this standard to consult andestablish appropriate safety and health practic
5、es and deter-mine the applicability of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:4D 2540 Test Method for Drop Weight Sensitivity of LiquidMonopropellants3. Summary of Method3.1 Restrictions are placed upon the ranges of impact toolmasses and striking surface diame
6、ters that may be used, and astandard sample thickness is prescribed for all tests.5Inaddition, procedures for sample preparation and treatment, aswell as procedures for detecting reactions through the use ofthe human senses, are outlined.3.2 Drop-weight impact tests are to be performed using thewell
7、-known Bruceton up-and-down method.6,73.3 Outlined is a method for normalizing data generated ondifferent impact apparatus.4. Significance and Use4.1 This method does not require an overall rigid standard-ization of the apparatus. Samples are tested either unconfinedor confined in confinement cups.
8、For confined tests, some ofthe important cup parameters, such as cup material, cup wallthickness, and fit between the cup and the striking pin, arestandardized. Data generated from unconfined and confinedtests will not, in general, exhibit the same relative scale ofsensitivities, and must be identif
9、ied as confined or unconfineddata and compared separately.4.2 This method applies to all testing where the intent is toestablish a relative sensitivity scale for hazardous materials. Itis not intended to prohibit testing process-thickness samplesnor prohibit the use of other than standard tool masse
10、s and1This method is under the jurisdiction of ASTM Committee E27 on HazardPotential of Chemicals and is the direct responsibility of Subcommittee E27.02 onThermal Stability.Current edition approved March 1, 2005. Published April 2005. Originallyapproved in 1979. Last previous edition approved in 19
11、99 as E 68079(1999)2This method is a modification of and contains concepts proposed by Hercules,Inc. personnel at Allegheny Ballistics Laboratory. The method was outlined bypersonnel of Pittsburgh Mining and Safety Research Center, Bureau of Mines,Pittsburgh, Pa. For additional information see footn
12、ote 3.3Smith, D., and Richardson, R. H., “Interpretation of Impact Sensitivity TestData,” Pyrodynamics, PYDYA, Vol 6, 1968, pp. 159178.4For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume inf
13、ormation, refer to the standards Document Summary page onthe ASTM website.5Becker, K. R., and Watson, R. W., “A Critique for Drop Weight ImpactTesting,” Proceedings of the Conference on the Standardization of Safety andPerformance Tests for Energetic Materials, Vol 1, September 1977, pp. 415430.Publ
14、ication ARLCD-SP-77004, U. S. Army Armament Research and DevelopmentCommand, Dover, N.J.6Dixon, W. J., and Massey, F. J. Jr., Introduction to Statistical Analysis,McGraw-Hill Book Co., Inc., 1957, pp. 319327.7Statistical Research Group, Princeton University, “Statistical Analysis for aNew Procedure
15、in Sensitivity Experiments,” AMP Report No. 101.1R, SRG-P, No.40, Submitted to Applied Mathematics Panel, National Defense Research Commit-tee, July 1944, 58 pp.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.striking diameters to ge
16、nerate data for special purposes or forin-house comparisons. In addition, the method is not intendedto restrict the generation of results at other than the H50pointas may be desirable for hazard analysis techniques.4.3 The normalized data will serve as a measure of therelative sensitivities of hazar
17、dous materials at the 50 % prob-ability of reaction level. The normalized H50values can also beused in conjunction with additional data relating to otherprobability of reaction levels (not a part of this method) toassess hazards associated with the manufacture, transportation,storage, and use of haz
18、ardous materials.5. Definitions5.1 H50valuea drop height with a 50 % probability ofreaction, as determined experimentally by the Bruceton up-and-down method.5.2 impact toolsthe drop weight, intermediate weight, andanvil.5.3 drop weightthat weight which is raised to a selectedheight and released. Thi
19、s weight does not impact the sampledirectly; rather it strikes another stationary weight that is incontact with the sample.5.4 intermediate weightthe stationary weight in contactwith the sample.5.5 anvilthe smooth, hardened surface upon which thetest sample or cup containing the sample rests.5.6 unc
20、onfined testa test in which the test sample isplaced directly upon the anvil with no lateral confinement.5.7 confined testa test in which the test sample is con-tained within a confinement cup (sample container), and theconfinement cup is then placed upon the anvil.5.8 confinement cupthe metal sampl
21、e container used inconfined tests.5.9 guide bushingthe steel bushing that surrounds, aligns,and holds the stationary intermediate weight in place.5.10 guide systemthe rails, wires, and shaft that guide thedrop weight during its fall.5.11 striking surfacethe hardened, smooth, circular bot-tom surface
22、 of the intermediate tool that is in contact with thetest sample.5.12 impact apparatus or machinethe total apparatusincluding the foundation parts, guide rails, electromagnet lift,winch, and tools.6. Apparatus6.1 A complete impact apparatus is the specialized appara-tus necessary for this method.6.2
23、 The masses of the drop weight ( m1) and intermediateweight (m2) should, preferably, be equal. However, theintermediate weight mass may be less than that of the dropweight mass so long as the mass ratio m2/m1is 0.6 or greater.This ensures that the force-time stimulus a test sample issubjected to wil
24、l be nonoscillatory in nature, and ensures thatthe transfer of energy from the drop weight to the intermediateweight does not vary significantly.6.3 The mass of the drop weight should be between 1.0 to3.5 kg.6.4 The hardness of all tooling surfaces involved in theimpact (drop weight, intermediate we
25、ight, and anvil) shouldhave a Rockwell C Hardness of 55 to 59 HRC.6.5 The diameter of the striking surface of the intermediateweight shall be 9.52 to 19.05 mm (38 to34 in.). These limitswere determined simply on the basis that data have beensuccessfully normalized for tool diameters in this range.6.
26、6 The finish on the striking surface of the intermediateweight and of the anvil, though not highly critical in tests withsolid explosives, should be a No. 8 grind (8 in.) or finer. Ifsubstantially different surface finishes are used, the dataobtained should be accompanied by a footnote specifying th
27、efinish used.6.7 In confined tests, the confinement cup shall be fabricatedfrom Type 302 stainless steel. The cup base thickness shallrange from 0.13 to 0.15 mm (0.005 to 0.006 in.). The outerperiphery of the striking pin shall be in contact with a smallportion of the arc joining the side and bottom
28、 of the cup.Although this permits greater energy losses in working themetal inside the cup than if the whole striking surface engagedonly the flat portion of the metal in the base of the cup, it doesensure better confinement with less flow of test material up thesides of the striking pin and cup. A
29、typical confinement cup isshown in Fig. 1. This, together with the striking pin dimensionsshown in Fig. 2, provide some insight on a suitable matingbetween the striking pin and cup.6.8 Experience has shown that an appreciable difference inthe behavior of the apparatus can result from the manner inwh
30、ich it is mounted. Thus, the machine should be mounted on,and firmly attached to, a solid concrete foundation, preferablyanchored to the foundation of a building (see Method D 2540).6.9 Fig. 3 illustrates a typical impact apparatus, and Figs. 4and 1 are detailed drawings of a drop weight, an interme
31、diateweight, and a confinement cup. Helpful notes on constructionof the tools are found in the Appendix. These tools andapparatus are in use at the U. S. Bureau of Mines, Bruceton,Pa., but are not necessarily the only acceptable designs. Alldesigns, however, should incorporate a device that captures
32、 thedrop weight after it rebounds to prevent further interactionswith the intermediate weight.FIG. 1 Confinement Cup Used as a Sample Container in ConfinedTestsE 680 79 (2005)27. Test Sample7.1 Sample thickness must be the same for all tests. This isachieved by using a constant volume per unit area
33、samplespread uniformly over that area. The standard is 31.5 mm3/cm2.This provides a distributed thickness of 0.315 mm (12.4 mils)and ensures the same energy input per unit mass of a given testmaterial no matter what the diameter of the striking surfacearea is. Thus, for a sample diameter of 12.7 mm
34、(0.50 in.), 40mm3of sample volume would be used. Proportionately largeror smaller sample volumes, varying in direct proportion to thesample, may be used so long as the sample volume per unitarea is 31.5 mm3/cm2. Errors in sample volume may be610 %, and sample measuring spoons having the appropriatev
35、olume can be machined or drilled for this purpose. In caseswhere it is desirable to test process thickness samples thatdiffer from the standard, simply indicate the thickness used,especially if the H50values appear in the same tables togetherwith H50values obtained using standard thickness samples.7
36、.1.1 In some cases, the sample consistency may prohibitthe sample from being measured in a measuring spoon. In theseinstances, the proper sample size can be determined by itsmass; M=rV, where V is the proper volume for a given samplearea, andr is the loose-packing density of the sample. Thedensity m
37、ay have to be determined if it has not been specified.7.2 Specifications of sample diameters to be used in con-junction with different diameter tools are as follows: ( a)inconfined tests, specifically, a test where the sample is confinedin a cylindrical cup, the sample diameter will be the same asth
38、e inside diameter of the cup. Hence, calculate a samplevolume or mass based upon the inside diameter of theconfinement cup, and (b) for unconfined tests, specifically, atest where the sample is spread directly upon the anvil, useabout a 0.33-mm (13-mil) thick template made from plastic,metal, or tap
39、e having a circular hole cut in it. Place the templateon the anvil, pile the sample in the hole, and scrape level witha spatula or straight edge. The hole diameter should, in allcases, be somewhat larger than the tool contact surfacediameter. Leave the template in place during the impact trial.The l
40、arger size will make it easy to miss striking the peripheryof the template hole during impact. The template also serves asan excellent means for keeping the sample inbounds. Therecommended template hole for a 12.7-mm (12-in.) diametertool is 15.9 mm (58 in.), but it may be 19.1 mm (34 in.) orlarger,
41、 as long as a proportionally larger sample is used. Here,it is important to remember that the sample volume or massused to obtain constant-thickness samples is based upon thetemplate diameter, not the tool diameter.7.2.1 In no case should the sample diameter be less than thatof the tool. The normali
42、zation method cannot be applied if thisFIG. 2 Intermediate Weight AssemblyFIG. 3 Bureau of Mines Impact ApparatusE 680 79 (2005)3is the case. Furthermore, the normalization method cannot beapplied to mixed data from confined and unconfined tests. It isgenerally applicable in the unconfined case. Inf
43、ormation islimited on applicability to the confined case. However, it isbelieved that data from confined trials could be normalizedprovided the confinement parameters are reasonably alike. Theimportant cup parameters that were standardized were given in6.7.8. Preparation of Apparatus8.1 Inspection c
44、hecks of the apparatus are an important partof the test procedure. This includes the physical condition ofcertain parts, alignment, and cleanliness.8.1.1 Physical Condition of Equipment Inspect the guiderails, or wires, or shafts periodically for evidence of nicks,frays, dirt, or other physical impa
45、irments, and eliminate anydefects that might impede the drop weight in its fall. Inspectthe drop weight, intermediate weight, and anvil, makingespecially sure that all metal surfaces that are involved in thecollision process are free from defects. Make sure that theintermediate weight slides through
46、 and rotates freely in theguide bushing without significant side play. Recondition orreplace the bottom surface (striking surface) of the intermedi-ate weight or top surface of the anvil if they show any evidenceof wear. Use a new, clean confinement cup each trial inconfined tests if confinement cup
47、s (sample containers) areused.8.1.2 AlignmentAlign the guide system, allowing the dropweight to fall along a path perpendicular to the plane of theearth within 60.25 deg. Misalignments of this magnitude caneasily be detected using a plumb line, since a 0.25-degmisalignment amounts to a 13-mm displac
48、ement over a3000-mm length.8.1.2.1 Align the bottom face (striking surface) of theintermediate weight and the top surface of the anvil. Thesesurfaces must be both plane and parallel. A convenient way tocheck this is with Prussian blue dye. Place a small amount ofthe dye on a piece of paper and inser
49、t the paper between theintermediate tool striking surface and anvil. By hand lower theintermediate 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 areasof the clean paper, making many different imprints. Be carefulnot to make a judgment solely on the basis of the first or secondimprint, since an excess of dye might smear and cover updefects. If the two surfaces are not parallel, a portion of oneside of the circle will be missing.Aconvex tool
