Measurement Parameters
Because movement is involved, many basic laws of physics apply which is why you will see terms like ‘Velocity’ and ‘Acceleration’. These terms are often confused or misunderstood, but don’t worry, there is no need to dig out your schoolbooks and slide-rules, we will explain the differences and identify which units are necessary to conduct Hand-Arm Vibration Assessments. There are two basic components of vibration, much the same as noise (there will be a lot of comparing noise to vibration, remember fundamentally, vibration is noise!).

Magnitude - amplitude, i.e. how much
Frequency - how often

Magnitude is broken down into many parameters, which can be measured in four different ways:

Displacement - Distance moved, usually measured in millimeters or micrometers
Velocity - Rate of change of distance, measured in metres per second
Acceleration - Rate of change of velocity, measured in metres per second squared
Jerk - Rate of change of acceleration, measured in metres per second cubed

Vibration can also be measured in dB although this does bring in the problems with non-linearity.
 
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