Fall hammer test

The sensitiveness of an explosive to impact is measured by determining the minimum height from which a given weight must be dropped in order to initiate detonation. Many forms of fall hammer test have been devised, the most important point of the various designs being the means adopted for retaining the explosive. A simple and practical method, used at Ardeer for many years, is shown in Fig. 6.7. In this the explosive is put... 

Fall hammer test. A test of the sensitiveness of explosives to impact using a weight which falls vertically (see p. 69). 

DSC showed that exothermic decomposition (-1200 J/g) begins at about 110°C. A falling hammer test indicated shock induced decomposition. Considerable caution is advised when employing this useful reagent. 

Ger for Falling Hammer Test). See IMPACT SENSITIVITY OR SHOCK SENSITIVITY TEST in Vol 1, p XVII and FI (Figure of Insensitiveness Test> described on p XII... 

Critical Energy of Impact (or Shock) in Detonation (or Explosion). This term signifies the minimum available energy of the falling hammer to produce explosions in impact sensitivity tests. It is designated as Ac and expressed... 

The Impact Test, also called Falling Weight Test was devised by W. Will, SS 1, 209(1906) and by H. Kast, SS 4, 263 (1909) and the history of test was reviewed by H. Koenen et al in Explosivstoffe 8, 178(1958). The test differs essentially from the gap test because its pressures (several hundred, or up to several thousand atmospheres) are much lower and its time scale (hundreds of microseconds, depending on the length of the hammer) much longer. In the test conducted at NOL, a 35-mg sample of expl or propint was placed on a... 

The literature reports several types of impact testing apparatus also known as fall hammer apparatus , for the determination of impact sensitivity of explosives. 

US BoE impact apparatus This method specifies the placement of 10 mg sample in a test cup. The mass of the fall hammer is usually 2 kg. 

AN grains 81.25% had impact sensitivity of 35cm with wt of falling hammer 10kg. Its deton velocity was 4l30m/sec and power by Trauzl Test 380ml)... 

Impact sensitivity varies widely from one chemical to another. Since it is not possible to test many chemicals with wide sensitivity ranges by a conventional drop hammer test, we have begun the trial use of a drop ball tester which allows us to change the weight of falling objects over a wide range 101. ... 

The sensitivity of azides to the impact of the falling hammer or weight, or to collisions with other massive objects, is among the properties commonly determined when a compound or artifact is fust prepared [5,8]. A crude impact test is easy to devise, but it is only one of several tests that assess the effect of comparatively weak mechanical action on explosives (the effect of strong shocks... 

For polymer sheets, the notched Izod impact strength is often reported (ASTM D256). In this test, as well as the Charpy impact test in the same ASTM standard, the polymer sample is subjected to an impact from a falling hammer, and the... 

The impact sensitivity of energetic compounds is tested with a so-called fall hammer equipment. Samples are exposed to the impact of falling weights from variable heights... 

In Table 1.2 impact sensitivity values of different azido compounds according to the BAM fall hammer procedure are listed and compared with the corresponding values of the well-known explosives trinitrotoluene (TNT) and nitroglycerine. For the BAM procedure it is necessary to have at least one positive event within a series of six trials (probability of at least 16.7%). In the case of the US drop hanuner tests (according to the Bruceton procedure) the required probabihty level is often 50% initiation within a series of at least 25 trials. 

Blatt (Ref 3), Urbanski (Ref 4) and ADL (Ref 3) give the following props of AzEtN Impact Sensitivity For a 50/50 mixt with sawdust, the max fall for no shots with a 10 lb wt was 2 . The corresponding values for NGc.and NG were 5" and 6 , respectively. Absorbed on filter paper the pure liq could be detonated by the blow of a hammer Power by Ballistic Mortar — 141% TNT Power by Trauzt Test — 150% TNT Velocity of Detonation — 1985 and 6550m/sec at sp gr 1.34... 

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