The Chemistry of Powder and Explosives - Sciencemadness Dot Org

26
PROPERTIES OF EXPLOSIVES
38 mm. in diameter and 6.4 mm. thick is placed upon it; a strip
of manila paper wide enough to extend beyond the top of the
composite cylinder and to form a container at its upper end is
wrapped and secured around it; 100 grams of explosive is placed
FIGURE 14. Small Trauzl Tests of Detonators. (Courtesy Western Cartridge
Company.)
in this container and fired, without tamping, by means of an
electric detonator. The result is reported as the compression of
the lead block, that is, as the difference between its height before
and its height after the explosion. The steel disc receives the
force of the explosion and transmits it to the lead cylinder. With-
I B
FIGURE 15. Aluminum Plate and Lead Plate Tests of Detonators. (Courtesy
Atlas Powder Company.)
out it, the lead cylinder would be so much deformed that its
height could not be measured.
In the lead plate test of detonators, the detonator is fired while
standing upright on a plate of pure lead. Plates 2 to 6 mm. thick
are used, most commonly 3 mm. A good detonator makes a cleancut
hole through the lead. The metal of the detonator case is
blown into small fragments which make fine and characteristic
markings on the lead plate radiating away from the place where