Datasets of high spatial resolution scans of the airborne ultrasound field at the front, back and left side of an ultrasonic welding machine

This dataset contains measuring data which are the result of investigations of the airborne ultrasound field of an ultrasonic welding machine. These investigations have been conducted within the scope of the EMPIR project 15HLT03: “Ears II - Metrology for modern hearing assessment and protecting public health from emerging noise sources”. In the context of “Ears II”, they served gaining knowledge for occupational safety and health. Here, the aim was to investigate the structure of the airborne ultrasound field at ultrasound related workplaces. Therefore, a reference workstation was set up in the laboratory of the Physikalisch-Technische Bundesanstalt (PTB). The airborne ultrasound field of a typical industrial source of airborne ultrasound (an ultrasonic welding machine) was measured with a scanning microphone system with a high spatial resolution.

The dataset contains data of 6 measurements:

• At the back of the ultrasonic welding machine at a vertical surface with dimensions 168 cm x 150 cm (width x height)
• At the left side of the ultrasonic welding machine at a vertical surface with dimensions 168 cm x 150 cm (width x height)
• At the front of the ultrasonic welding machine at a horizontal surface with dimensions 168 cm x 75 cm (width x depth)
• At the front of the ultrasonic welding machine at a vertical surface with dimensions 168 cm x 150 cm (width x height) with a distance of 24 cm to the sonotrode
• At the front of the ultrasonic welding machine at a vertical surface with dimensions 168 cm x 150 cm (width x height) with a distance of 99 cm to the sonotrode
• At the front of the ultrasonic welding machine in a volume with dimensions 58 cm x 33 cm x 50 cm (width x depth x height) 

The measuring data is the square of the absolute value of the discrete Fourier transform of the signal voltage re 1 V² represented in the frequency domain, converted by fast Fourier transform, in the frequency range 0 – 100 kHz with a frequency resolution of 15.625 Hz. The data can be converted to sound pressure levels (SPL) using the calibration values published as a supplementary dataset.