ARMY EDGEWOOD CHEMICAL BIOLOGICAL CENTER APG MD ABERDEEN PROVING GROUND United States
Pyrotechnic strobe compositions exhibit an oscillatory combustion characterized by a periodic alternation of a dark phase and a flash phase. Many traditional strobe mixtures contain toxic substances, including dichromates and barium compounds. The investigation into a less-toxic strobe mixture using strontium led to the discovery of an extremely slow strobe this mixture produced a pulse or flash phase approximately once a minute. This paper describes the evaluation of the slow strobes pulse rate, based on the mesh size of the metal powder and the effect of the variation of strontium nitrate and potassium nitrate concentration. Small test pellets of this less-toxic strobe mixture, containing only 10 g of pyrotechnic composition, had burn times of more than 5 min, with a single, bright flash approximately once every 60 s. The compositions dark phase provided only an extremely faint glow that under normal circumstances would appear to have been extinguished, only to flash at the previously stated predictable instant. This composition presents an opportunity to study a potential reason for a common dangerous situation known as a hang fire and warrants further study.