The Chemistry of Powder and Explosives - Sciencemadness Dot Org

422 PRIMARY EXPLOSIVES, DETONATORS, AND PRIMERS
plosion imparts to the nail is measured. The sand test, in which
the detonator is fired in the center of a mass of carefully screened
sand contained in a suitable bomb and the sand which has been
pulverized is screened off and weighed, is the most precise and
significant of the tests on detonators. It is a real test of brisance,
and its usefulness is not limited to the study of detonators but
may be extended to the study of high explosives as well. Thus,
FIGURE 98. U. S. Bureau of Mines Sand Test Bomb No. 1. (Courtesy
U. S. Bureau of Mines.) At left, assembled for making the test. At right,
disassembled showing the parts. Two covers, one with a single hole for
miner's fuse, the other with two holes for the two wires of an electric
detonator.
two explosives may be compared by loading equal amounts in
detonator shells, priming with equal amounts of the same initiator,
firing in the sand test bomb, and comparing the amounts
of sand pulverized.
The sand test was devised in 1910 by Walter 0. Snelling, explosives
chemist of the U. S. Bureau of Mines, who worked out
the technique of its operation and designed the standard Bureau
of Mines sand test bomb No. 1 which was used in his own investigations
and in those of Storm and Cope/ 0 Munroe and Taylor 31
30 Snelling, Proc. Eng. Soc. Western Pennsylvania, 28, 673