ABSTRACT
In almost every branch of engineering, vibration phenomena are generally measured with two main objectives in mind: the rst is to determine the vibration levels of a structure or a machine in operating conditions, while the second is to validate theoretical models or predictions. Thanks to the developments and advances of electronic instrumentation and computer resources of the last few decades, both types of measurements can now be performed effectively, also in consideration of the fact that the increasing need for accurate and sophisticated measurements has been brought about by the design of lighter, more exible and low-damped structures, which, in general, are more susceptible to the action of dynamic forces.
