NOVEL MEASUREMENT TECHNIQUES AND MEASUREMENT METHODS FOR THE DETERMINATION OF ULTRASOUND NOISE EXPOSURE AT WORK PLACES

摘要

Ultrasound technology is widely used in industrial and medical technology and, thus, a significant increase in the number of workplaces exposed to airborne ultrasound has been registered. Although it is assumed that airborne ultrasound cannot be heard it can be perceived by humans and this has led to reports about various adverse effects. A thorough investigation of the noise exposure, based on proven and traceable measurements, is indispensable to ensure a contemporary occupational safety quality. Since no standardised methods and measurement techniques exist to date, appropriate technology is developed in a project funded by the European Metrology Programme for Innovation and Research (EMPIR) and results are presented in this contribution. Measurement set-ups were developed that allow the determination of sound fields with the required wide frequency bandwidth and high spatial resolution. By the aid of these techniques the 3-dimensional sound pressure distribution around a representative ultrasound welding machine was determined. Simplified measurement methods were developed that can be applied by measurement service technicians. For this purpose, sound level meters with an extended frequency range and analysis tools were developed. This work contributes to an improvement of the assessment of ultrasound noise at workplaces and, thus, to improve the occupational safety quality.