Nowadays, sources of airborne ultrasound can be found in many areas of life. In industrial workplaces, technologies with high-performance ultrasound have found numerous and diverse applications. Due to the increasing distribution of ultrasound technologies, a growing number of people is exposed to airborne ultrasound. Employers are legally obliged to carry out risk assessments to protect employees against actual and possible risks to their health and safety. For this purpose, the exposure to sound - including ultrasound - must be determined and evaluated. Until now, however, no practical, scientifically grounded, standardized measurement procedure has existed that is able to measure the exposure to airborne ultrasound in the workplace. The present work is devoted to the development of such a measurement procedure, which considers the characteristics of airborne ultrasound and is suitable for use in the context of occupational safety and health. After developing a laboratory measuring system for spatially high-resolution measurements of airborne ultrasoundfields in the laboratories of the Physikalisch-Technische Bundesanstalt (PTB), the soundfield of a representative industrial source of airborne ultrasound was measured and the influence of a person in the sound field was examined. The results showed finely structured soundfields with maximum sound pressure levels of more than 130 dB (re 20 μPa). The heterogeneous spatial distributions of sound pressure levels were characterized by an omnidirectional sound emission of the sound source and local sound pressure extrema with large differences up to 40 dB within small distances in the millimeter range. The examination results confirmed that the measurement methods established in the auditory sound range are unsuitable for use in the ultrasound range, and motivated a new measurement method, in which the microphone is guided through the measurement volume in a wiping manner during data acquisition. To meet the requirements in working protection according to a practical, time-saving and equally valid exposure determination, investigations with regard to minimum requirements for the resolution and microphone size have been executed. For this purpose, the sound field data were parameterized regarding the sound pressure levels and the spatial structure with methods of statistics and image processing. According to a systematic variation of the resolution and simulations of measurements with different microphone sizes, corresponding minimum requirements were derived from the parameters and based on previously defined acceptance limits. A validation of the developed measurement procedure was carried out within the framework of measurements in the field and confirmed the practical suitability, robustness and general validity of the measurement procedure for different ultrasonic modalities.weiterlesen