The field of "Acoustics, Ultrasound and Vibration" regroups four phenomena, all concerning mechanical waves in various media (air, water and solids). These four phenomena airborne sound, ultrasound, vibration and underwater acoustics are encountered in a wide spectrum of applications, many of which are experienced in everyday life, for frequency regions covering more than seven orders of magnitude (0.1 Hz up to 15 MHz). Fundamental metrology is carried out to support a wide range of applications, some of which are listed below. Measurements and comparisons to establish the degrees of equivalence between different national institutes around the world are important to obtain a robust and coherent basis for worldwide calibration services.
- Airborne sound has a strong impact on the population via industry, urban planning, health, safety and environmental protection. Benefits extend across all society, from urban to rural populations, and across all stages of life, from birth in the form of neonatal screening into old age by hearing conservation. Sophisticated and objective audiological practices, acoustical perceived qualities and low-cost calibrated sensors are some examples in this area that need metrological support.
- Ultrasound is essentially used for medical purposes and in industry. Ultrasound techniques are familiar to the population as a diagnostic tool. They are also used for drug delivery and therapeutic means. In industry it is commonly applied as a means of generating macroscopic changes in materials, a popular method for cleaning and an alternative for sterilizing equipment.
- Vibration measurements are commonly applied in industry if the automotive areas, for aerospace and testing, and are important for workers safety. They also cover shock acceleration measurements. Applications to seismic studies and predictions are other applications.
- Underwater acoustic techniques are the methods of choice for most marine applications requiring remote imaging, communication, and mapping in sea water where techniques based on electromagnetic waves suffer from limited range due to high levels of absorption. It is of great importance for the defence sector, but also exploited for environmental applications and for survey for oil and gas explorations.