Functioning tests of detonators

The Bruceton method is also frequently used in other destructive tests, eg in functioning tests of detonators, gap tests for shock sensitivity, or in tests where the test alters a sample so that it is no longer in its original state... 

Functioning Tests of Detonators are described in US Army Specification 50—78—7, p 8 and US Military Specification MIL-D-2493... 

Table nt Detonator Functioning Tests of Spheroidal and Conventional Dextrinated Lead Azide... 

The newly developed equation of state was applied to the calculation of detonation properties. In this context, one stringent test of any equation of state is the prediction of detonation velocities as a function of initial densities, and we chose for this purpose PETN. The Cheetah results are shown in Figure 7 along with the experimental data.53 The agreement is again very good. 

Accdg to Ref 14, p 68 Ref 26a, p 5-21, " the total work capacity of an explosive is a fun ction of the total available heat liberated at the instant of detonation, but its power is determined by the rate at which the heat energy is liberated. In the past, measurement was made of the maximum pressure developed by detonation and this was considered an expression of the work function of the explosive. However, such tests were made with explosive charges having relatively low loading density values and it was then necessary to calculate by extrapolation the pressure produced by an explosive in its own volume... 

Drop Safety of Bomb Test or Bomb Functioning Test. Drop safety of bomb may be defined as the maximum height of drop for a given bomb oo a given surface without causing the bomb to fail, or without detonation An empirical formula computed at Aberdeen PG before WWII.as a.result of dropping various bombs from an airplane at a height of ca 20 00 ft on 2 ft deep reinforced concrete hard surface laid over a suitable... 

Both the friction pendulum and deton hazard (solv wet) tests show that Benite reacts similarly to single base, M-18 proplnt and therefore may be considered a Class 2 expl hazard when wet. The functioning characteristics of of benite are relatively unaffected by minor changes in dimensions of the strands and formulation (Ref 35)... 

Another test for explosives is the speed at which a detonation travels. This speed is usually in the range of thousands of m/sec. Speed of detonation is found to be a function of the kind of explosive and state of compaction. There is an optimum state of compaction beyond which the explosive tends to become deadpressed, in which state it is difficult to make the whole sample explode. Below the point of optimum compaction the rate of detonation is found to be directly proportional to the density of the sample. Some maximum detonation rates are listed below in m/sec for some common explosives ... 

Batch number Weight of detonator charges (mg) Number tested Number of high-order functions Perforations (mils) Avg. 

Of the CMCs tested, types B50, 4MP, and 4M6F produced a lead azide which met the requirements of the detonator functioning test at the 35-mg loading level. Curiously, the failing lead azides exhibited "dead pressing" properties not usually associated with lead azide (Chapter 5). 

Comparing the products from batches 28 and 29 with batch 14, it can be deduced that varying the time of addition of the reactant solutions from 30 to 60 min does not have a significant effect. There is one anomalous result in that batch 29 did not pass the detonator functioning test at the 35-mg level but did pass at the 25-mg level. 

More detailed study of the transmission of detonation through the air also includes the determination of the functional relationship between the key parameters in the transmission of detonation the performance and the mass of the donor charge and the distance at wfiich detonation transmission occurs under defined testing conditions. The influence of other parameters such as donor shape, existence, and kind of donor confinement can also be included into the study. 

The MCI is created by detonating or igniting a test round(s), or item(s) with all items in the operational configuration in the shield, including the equipment or reasonable simulation thereof, that performs the intended function on the munitions. If the shield is intended to be used for a variety of rounds, the one(s) having the most severe effects for overpressure, fragmentation, thermal emissions and shape charge effects is to be tested. 

Given the unreliability of the stab-initiated tests, a second round of testing was performed using a hot nichrome wire to initiate the detonators in place of the NOL-130 stab mix and firing pin. This test was successful and all nine detonators functioned, showing that DBX-1 is more susceptible to this method of initiation. Figure 8 shows the electrical ignition setup. 

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