Development, Validation, and Application of an On-Board Sound Intensity Calibrator for Tire–Noise Measurement

Abstract

The standardization and growth of the application of the measurement of tire–pavement noise with on-board sound intensity (OBSI) has created a need for relative calibration and validation of the complete data acquisition systems of different users. The devices available to perform sound intensity calibration generally rely on external signal generators to drive a coupler or are limited to calibration at only one frequency. A system has been developed using components from various suppliers to perform relative calibration between users over the range from 400 to 5,000 Hz. The repeatability of the OBSI calibrator was quantified in bench-top testing, and its reproducibility was examined through application by multiple users. The stability of the calibrator has been confirmed over the past 3 years and was found to be consistent when applied by multiple users. The availability and performance of the calibrator present the opportunity for users to have confidence in their systems, particularly systems developed internally. The calibrator also facilitates the exchange of OBSI results between users, enabling the use of noise performance as one basis for pavement selection. This paper presents the development, validation, and application of the OBSI calibrator.