Noise measurements and quality assurance

A quality assurance program was developed for calibration of noise measurement equipment and the certification of personnel responsible for making noise measurements. The program is designed for use by the eleven districts and the transportation laboratory of the California Department of Transportation (Caltrans). An evaluation of various equipment calibration program alternatives was made and the most suitable to Caltrans' needs was selected and developed in detail. This program involves a mobile calibration and operator testing set-up that can be taken to each District office on an annual basis. Traceability to the National Bureau of Standards (NBS) is established by using standard microphones periodically calibrated by NBS.