U : Sound and Vibration Definitions, Terms, Units, Measurements ..

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UKAS : United Kingdom Accreditation Service is the national accreditation body recognised by government to assess, against internationally agreed standards, ...

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Ultrasound IEC Definition,

acoustic oscillation whose frequency is above the high-frequency limit of audible sound (about 16 kHz)

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Uncoupled Mode IEC Definition,

normal mode oscillating independently of other modes

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Undamped Natural Frequency IEC Definition,

frequency of free oscillation resulting from only elastic and inertial forces of the system

Undamped Natural Frequency the natural frequency of a structure.

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Under-range the input to the Sound Level Meter is too low for the current measurement range. Change the range.

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Under-range % percentage of time an under range occurred

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Units : SI Units