Study On A Stored Testing System For Simultaneous Measurement Of The Speed And Pressure Of Shock Wave

In response to the demands from a proving ground, and based on the analyses of current methods and characteristics of shock wave testing stated in a wide variety of literature, a strong functional stored system, which can be based on different piezoresistive transducers, is developed for simultaneously testing speed and pressure of shock wave.Simultaneous testing of speed and pressure of shock wave can be described as follows: The pressure-time curve of shock wave can be obtained by a piezoresistive transducer (A) placed at a certain location from which the shock wave passes. Two transducers B and C, which record the time when the shock wave front arrives, are placed on both sides of location (A) with equal distance, the average shock wave speed at location (A) can be calculated from the distance B to C and the time that the shock wave needs to travel from B to C. All the tested signals are stored on a pint-sized system of independent function. Therefore from an experiment both the overpressure change and the maximum value of overpressure (Pmax) of shock wave can be obtained, with Pmax calculated from speed of shock wave.Though based on piezoresistive transducer, the stored system also functions with absolute pressure transducer, manometer pressure transducer, and differential pressure transducer equipped. The circuit in the stored system is self-adaptive, which makes possible automatic adjustment of zero output within a wide range of voltage (-100mV~+100mV).The input voltage of the piezoresistive transducer, gain, sampling frequency and negative delay can respectively be graded through programming. The stored system is specially designed to have two modes of trigger (namely, external trigger through wire breakage and inner trigger through overpressure signal), reading software and interface circuit that are of both serial and parallel properties, and automatic examination of status and power input at fixed time; The above designs considerably contribute to its flexibility and practicability.The stored testing system developed has been statically and dynamically calibrated and its effectiveness has been proved by the data it collected within different measurement ranges in shock wave experiments.