Blast pressure and TNT-equivalency of small electric detonators comprised of lead azide

Abstract

Blast pressure from a small electric detonator, comprised of 100-mg lead azide as its main explosive, was measured and its trinitrotoluene (TNT)-equivalency was evaluated accordingly. The measurement of blast pressure in the proper direction suppressed oscillatory noise on the blast wave profile; therefore, the blast pressure from the sole detonator was clearly and definitively evaluated. The relationships between scaled distance and peak-overpressure, as well as scaled positive impulse, were compared to those of MITI87, which is representative of TNT surface-explosion data obtained by National Chemical Laboratory for Industry (National Institute of Advanced Industrial Science and Technology at present) in Japan. The TNT-equivalency of this detonator was conclusively evaluated as 0.32-0.33.