Contribution
High pressure calibration by standing wave resonance method
* Presenting author
Abstract:
In recent years the need for measuring high sound pressures above 175 dBSPL have arisen due to both environmental and performance considerations in the aviation and space industry. Classical calibration in the sense that the difference between Device under Test and Reference Unit is below a certain value and the associated distortion is below 1% is not in scope here – this proposed solution is intended for determining failure of the DUT after use, as the inherent non-linearities of air is not insignificant at these sound pressures. In general the classical microphone is not well suited for these level of sound pressure and the system for calibration does also have limitations with respect to the achievable levels of sound pressure. By using microphones based on accelerometers and more powerful sound sources this solution has proved viable.A solution for the problem described above have been theorized, simulated using Finite Element Modelling and subsequently build to shown a viable solution for future use in cases where calibration in excess 180 dBSPL is required.