Autonomous gauge for blast impulse determination close to explosive charges

This paper reports on a new gauge for blast impulse determination close to explosive charges. The gauge is based on the autonomous data recorder g-rec developed at the Ernst-Mach-Institute for data acquisition in harsh environments. Combined with an acceleration sensor these data recorders allow for the direct determination of the momentum transferred to an object by a blast wave even in the immediate vicinity of the explosive charge. From this the blast impulse can be determined. Using autonomous electronics distinct advantages are gained compared to classical passive momentum traps. The paper summarizes the properties of the g-rec recorder and describes the setup of the autonomous momentum trap in detail. Numerical simulations are presented which illustrate the gauge performance and its limitations. Tests with 1 kg charges demonstrate the feasibility of the approach. Good agreement was found between simulations and tests. The application range of the gauges is determined by the measurement range of the built-in acceleration sensor and its overall dimensions and weight. The present configuration is designed for distances between ∼0.3 and 1 m from charges between several 100 g and several kilograms. Data were successfully collected down to reduced distances of 0.25 m/kg1/3. Minor changes in gauge dimensions, weight, or measurement range enable the gauges to be deployed at even closer distances.