Author(s): Wolff Andrea, Ullisch-Nelken Christian, Schöneweiß Robert, Kling Christoph
Purpose: In an industrial context, the application of ultrasonic technology has increased greatly during the last decades. National regulations in Europe typically do not provide guidance on handling ultrasound exposure at the workplace, although harmlessness of long-time exposure to airborne ultrasound is not proven yet. One reason for this deficit is the lack of a reliable measurement method without which an assessment of exposure to airborne ultrasound is not possible. Within the “European Metrology Programme for Innovation and Research” the Institute for Occupational Safety and Health and the National Metrology Institute of Germany developed a measurement procedure for measuring industrial ultrasonic noise.\nMethods: Existing measurement methods for audible sound were reviewed regarding their suitability to ultrasonic frequencies. Additionally, data from ultrasound-exposed workplaces was collected and evaluated in order to construct a reference workplace in the laboratory. This workplace allows for repeatable, reproducible and comparable measurements among the involved institutions. An ultrasonic welding machine served as source for pulsed and continuous sound emission. At this workplace simulated practical measurements as well as high spatial resolution scans of the sound field were conducted. Also influences of environmental factors and the presence of workers on the measurement results were investigated. Based on these laboratory investigations a measurement method was developed and tested in situ.\nResults and conclusion: Based on ISO 9612 and the German guideline VDI 3766 a novel procedure for measuring airborne ultrasound for occupational safety and health purposes was developed. Field tests were conducted and evaluated to adapt the method to practical needs. This method can serve as a basis for assessment and regulation of airborne ultrasound exposure at the workplace.
Name: Dr Andrea Wolff