Assessing the Accuracy of Microphone Measurements of Small-Scale Height-of-Burst Explosive Charges

Author(s):

Elliot R. Wainwright, Amee L. Polk, Dakota Scott, Ronnie Thompson, Ray Sparks, Will Sickles, Eugene Summers, Richard Benjamin, and Steven W. Dean

Abstract:

In this work, the pressure profile of height-of-burst detonations from three sizes of spherical C-4 charges (17, 54, and 152 g, corresponding to TNT equivalent scaled distances of approximately 14.8, 10.1, and 7.1 kg/m^1/3, respectively) were measured using laboratory-grade pressure-field microphones. We assessed the time of arrival, peak pressure, and pressure decay behavior as a function of charge mass and compared experimental results with tabulated Kingery-Bulmash and Conventional Weapons (ConWep) data, in addition to simulations performed in the fast-running code, BlastX. In particular, we found excellent agreement between BlastX predictions and measured times of arrival of the shock wave, when these are combined with known gauge distance, all other values of the incident pressure wave can be derived. We highlight the advantages of these microphones over traditional piezoelectric pencil probe gauges for blast measurements—in particular, the variable sensitivity allowing for high-fidelity measurements across a wide range of scaled distances and utility for smaller events such as microscale shock waves.