Impact test apparatus drop weight

IMPACT SENSITIVITY OR SHOCK SENSITIVITY TESTS (Drop Weight or Falling Weight Tests). A list of various tests with refs is given in Vol 1, p XVII. Brief descriptions of US Bureau of Mines (BM) Apparatus and of Picatinny Arsenal (PA) Apparatus are also given on p XVII. British test called Figure of Insensitiveness (FI) is described on p XII (See also Refs 36, 38d, 41, 42, 53, 55b,... 

B) Drop Weight Impact Test used at LASL is a modified version of machine developed by E.H. Eyster R.F. Davis at the Explosives Research Laboratory, Bruceton, Pa and described in OSRD 5744(1945). The apparatus is known as "ERL Machine . 

Impact Machines and Impact Tests. One frequently hears the remark that there are as many types of impact machines as there are explosives test laboratories. This is somewhat misleading. In reality, all laboratories use essentially similar equipment but test procedures, and test data analyses differ. Basically an impact machine is an apparatus that drops a steel weight from a pre-determined height onto a plunger or striker resting on top of the test sample which is placed on a steel anvil... 

Figure 19. Impact tests of lead azide and lead azide with different liquids [56] Picatinny Arsenal apparatus 1-kg weight dropped at indicated heights 20 samples per data point.

Impact Sensitivity by Brucetofl No 3 Apparatus, 50% positive in brass cups with 5kg weight at 90cm drop, vs 50cm for RDX Power by Ballistic. Mortar Test, 127% TNT Power by Trauzl Lead Block Test, 129% TNT Rate of Detonation. See Detonation Velocity Rifle Bullet Test. In 7 trials conducted in Canada with charges placed in steel pipe nipples — 5 passed, 1 detonated and 1 partially detonated... 

Among the important tests which are made on explosives are the determinations of their sensitivity to impact and to temperature, that is, of the distance through which a falling weight must drop upon them to cause them to explode or to inflame, and of the temperatures at which they inflame, explode, or puff spontaneously. At different places different machines and apparatus are used, and the numerical results differ in consequence from laboratory to laboratory. 

The results are reported as foot-pounds of energy absorbed in failing the bond of a 1-square inch specimen. Some machines use gravity to accelerate the given load that strikes the test specimea A variation of the gravity-impact methods uses a series of weight multiplied by the distance dropped. Other more sophisticated apparatus uses compressed air to decrease the time of load application to as little as 10 seconds. ... 

The Bureau of Mines impact apparatus indicates TMETN is as sensitive as nitroglycerin, with a drop height of four centimeters for a two kilogram weight. The five second explosion temperature test value is 235°C and TMETN detonates with both the metal and fiber shoe in the pendulum friction test. 

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