Characterization of Nonel Tubes for Shock Wave Generation and Sensor Calibration

Abstract. Integrated electronics piezo-electric (IEPE) sensors are often used in blast overpressure measurements. They need to be calibrated in order to provide accurate data, but sending them to an authorized company for calibrations can be costly and time-consuming. This paper presents a laboratory-friendly alternative for sensor calibration, by using nonel tubes (thin plastic tubes with a thin coating of HMX/Al mixture) to generate repeatable overpressure inside a 2 m shock tube. By calculating the overpressure from shock wave velocity and comparing it to a value measured by a sensor, a recalibration is possible, making this a simple, quick, and cost-efficient method of IEPE pressure sensor calibration. Minimal effective length of nonels needed for repeatable overpressure generation, and combinations of up to 9 nonels in a single setting were experimentally tested. Simulations in the blastFoam solver were carried out to establish TNT equivalency of the nonel tubes. This would further allow to check the sensor calibration when used in a field setting for actual blast wave measurements and simulations.