PERFORMANCE TEST OF A MODIFIED HOPKINSON PRESSURE BAR

摘要

two Hopkinson Pressure Bars were constructed at the Naval Ordnance Laboratory from British drawings. The pressure bars are devices used to obtain a measure of the output of detonators or other small explosive charges. The recording system of these bars was modified by substituting a photoelectric timer for the pendulum of the original design. A series of tests was then conducted to compare the performance of the bars to that of detonator tests used commonly in thi3 country. In these tests results obtained from the pressure bars were corapared to the results of sand bomb tests, lead plate tests, copper block and Traual block testa, and a German test set called the Stauchapparato. A direct comparison of the nsitivities and consistency of measuringaevices, and their ability to detect deterioration was obtained. It was concluded that the pressure bars offered the best combination of sensitivity and reliability and that the directional output neasurenents obtained were more often than not an advantage in detonator work.