A dynamic calibration method of free-field pressure sensor based on Hopkinson bar

This paper presents a dynamic calibration method for the dynamic sensitivity coefficient of a free-field pressure sensor working in liquid. In this method, an oil-filled auxiliary tool has been designed and the free-field pressure sensor sealed in the tool was loaded by a Hopkinson bar that could generate a stress wave with known amplitude. The strain signal of the Hopkinson bar and the output signal of the sensor were collected and processed based on the Hopkinson experimental principle and the dynamic sensitivity coefficient of the sensor was calibrated. A calibrated PCB W138A10 pressure sensor was re-calibrated and its dynamic sensitivity coefficient was obtained. Compared with the parameters from the calibration certificate of this sensor, this experimental result is reliable. This method can obtain the more accurate result and can be widely used in the dynamic calibration of free-field pressure sensors that work in liquid.