Measurement arrangement for calibrating ultrasonic shock wave sensors

A measurement arrangement for calibrating ultrasonic shock wave sensors, comprising:

• a) a generator device generating an ultrasonic measurement shock wave:
• b) a sound-carrying medium transmitting said measurement shock wave generated by said generator device;
• c) a measurement volume filled with a gaseous substance having a lower acoustic impedance than the sound-carrying medium;
• d) a film having a first surface that is adjacent to the sound-carrying medium and a second surface that is adjacent to the measurement volume, said film having a sufficiently low thickness and low mass to follow excursions of molecules in the sound-carrying medium caused by said measurement shock wave and being configured to reflect light at least in a reflector region thereof;
• e) means spaced away from the reflector region and arranged in the measurement volume for irradiating the reflector region with light and for receiving light reflected from said reflector region that is modulated in intensity by excursion of the film caused by said measurement shock wave;
• and
• f) an analysis unit in connection with said means for irradiating and receiving light, said analysis unit driving from a change in intensity of the reflected light a reference pressure signal for an ultrasonic shock wave sensor to be calibrated, said reference pressure signal being proportional to a time derivative of the excursion of the film and corresponding to an acoustic pressure of said measurement shock wave.