R. Meyer J. Köhler A. Homburg Explosives

Impact Sensitivity
same hardness*). Cylinders and rings are renewed for each falling test
procedure. If the sample is a powder or a paste, the upper cylinder is
slightly pressed into the charged confinement device as far as it will go
without flattening the sample. If liquids are tested, the distance between
the cylinders is 2 mm. The charged device is put on the anvil of
the fallhammer apparatus, and the falling weight, guided by two steel
rods, is unlocked. For sensitive explosives such as primary explosives,
a small fallhammer is used for insensitive explosives a large hammer.
The small hammer involves the use of fall weight of up to 1000 g, while
the fall weights utilized with the large hammer are 1, 5 and 10 kg. The
fall heights are 10–50 cm for the 1-kg weight, 15–50 cm for the 5-kg
weight and 35–50 cm for the 10-kg weight. This method is the recommended
test method in the UN-recommendations for the transport of
dangerous goods and it is standardized as EN 13631-4 as a so-called
Harmonized European Standard.
Fig. 16. Fallhammer confinement device
The influence of friction test results is thus elliminated.
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* The ground and hardened cylinders and rings are standard parts for ball
bearings; they are available on the market.