R. Meyer J. Köhler A. Homburg Explosives

Heat Sensitivity
Heat Sensitivity
162
thermische Sensibilität; sensitiveness to Heat;
sensibilité au chauffage
Heat sensitivity is determined by testing the flammability of explosives
brought into contact with glowing objects, flame, sparks, the initiating
flame of a black powder safety fuse, a red-hot iron rod, or a flame.
RID (Règlement International concernant le Transport des Marchandises
Dangereuses) describes a method, in which a sample of
about 500 g of the explosive, accommodated in a metal can of given
dimensions, is exposed to a wood fire, and its behavior (combustion,
intense decomposition or detonation) is observed.
In response to a suggestion made by Koenen (Bundesanstalt für
Materialprüfung, Berlin, Germany), these tests, which are carried out
with the purpose of evaluating the safety during transport, were improved
as described below; the method is known as the “steel sleeve
test” (Koenen test).
Koenen Test Procedure
The sample substance is introduced into a cylindrical steel sleeve
(25 mm dia.V24 mm dia.V75 mm) up to a height of 60 mm, and the
capsule is closed with a nozzle plate with a central hole of a given
diameter. The diameter of the hole can vary between 1 and 20 mm;
when the plate is not employed, the effect is equivalent to that of a
24-mm hole. The charged sleeve is placed inside a protective box and
is simultaneously heated by four burners; the time elapsed up to
incipient combustion and the duration of the combustion itself are
measured with a stop watch. The plate perforation diameter is varied,
and the limiting perforation diameter corresponding to an explosion
caused by accumulation of pressure inside the steel sleeve is determined.
Explosion is understood to mean fragmentation of the sleeve
into three or more fragments or into a greater number of smaller
fragments.