U : Sound and Vibration Definitions, Terms, Units, Measurements ..
UKAS : United Kingdom Accreditation Service is the national accreditation body recognised by government to assess, against internationally agreed standards, ...
acoustic oscillation whose frequency is above the high-frequency limit of audible sound (about 16 kHz)
normal mode oscillating independently of other modes
frequency of free oscillation resulting from only elastic and inertial forces of the system
Undamped Natural Frequency the natural frequency of a structure.
Under-range the input to the Sound Level Meter is too low for the current measurement range. Change the range.
Under-range % percentage of time an under range occurred
Units : SI Units