Secondary system dynamic pressure

At present, traceability to the SI unit pascal is maintained through static pressure measurements. However, the majority of measurements carried out in industry, healthcare and the rest of society take place under dynamic conditions. That is, conditions where the pressure changes over time. In order to verify that a measuring instrument can handle the prevailing rate of change with sufficient accuracy, the instrument must also be dynamically calibrated.

Through participation in previous projects, the National Laboratory for Pressure and Vacuum at RISE is at the forefront of international development of traceable dynamic pressure measurements in the gas phase. RISE's previous work has been done using the shock tube that is available as a resource in the laboratory. However, the shock tube is limited downwards both in the pressures and in the frequency content that can be generated.

This project aims to develop a secondary system that can generate dynamic pressures that overlap with static pressure standards and with the shock tube both in pressure levels and in frequency content. In this sense, dynamic pressure sensors will also be able to be characterised in this intermediate area. Traceability is obtained through a reference sensor that is both calibrated statically and characterized by the shock tube.

In the longer term, the secondary system may also bridge the amplitude gap between acoustic pressures and the pressures generated by shock tubes. The secondary system will also be an important resource in future research projects, which may, for example, aim to develop pressure standards based on optical measurements of the quantum state of the pressure medium