Investigation on gas pressure measurement inside small caliber weapons with piezoelectric transducers
Lamine Elkarous, Marc Pirlot, Jean‐Claude Golinval, Marc Maldague · ORBi (University of Liège) · 2011
This study carried out at the ballistic laboratory of the Royal Military Academy examined the comparison results between the NATO standard Kistler type 6215, the HPI type GP6 and the SAAMI standard PCB type 117B104 piezoelectric high pressure transducers for the measurement of gas pressure inside a small caliber weapon.To achieve this goal, a barrel of caliber .50inch manufactured according to military standards was used to fire different types of 12.7x99 mm ammunition [1].The transducers were installed in the same mounting position in respect to barrel length but displaced by 90 degrees to each other.The exit velocity was also measured to get a reference value.Results of the study showed that although there was an agreement on the pressure-time curves given by the three ballistic transducers, there were nevertheless, some significant differences in the peak pressure which might be strongly related both to the measuring techniques and the calibration methods.Recommendations were made to develop in-situ a reliable dynamic calibration method so as to satisfy the demand to cover the whole range in amplitude and frequency.A solution based on the use of a piston in contact with an oil-filled pressure chamber has been developed and tested.The high pressure is obtained by impacting the piston with a mass launched from an air gun.However, this method still requires improvements.Further recommendation can be made to consider measurement uncertainty calculation of the high pulse pressure generator.