The Auto Spectral Density or Auto RMS spectrum analyses uses Fourier Transforms to process optionally overlapped sections of the input data. The result of each Fourier analysed section is called…
One of the most searched for and read topics on the Noise & Vibration Measurement Blog is that of converting between measurements of acceleration, velocity and displacement. To help anyone…
Understanding filters is actually simpler than it may first seem. Creating a filter is another story; it’s like being able to drive a car without having to know the intricate…
If you are visiting the SAE 2013 Noise and Vibration Conference and Exhibition in Grand Rapids (May 20th - 23rd) then please come along and see us at booth 409.…
Assuming one wants a frequency spectrum from an acquired time measurement, it is generally accepted that averaging of a signal in the time domain is not very useful due to…
For some time now it has been conventional ‘wisdom’ that using time based digital integration may cause amplitude errors in the result and that these get worse as the frequency increases. As a result of this, integration using Omega arithmetic has been prevalent by using Fourier Transforms of the signal. This, of course, remains a valid approach and is particularly useful if the data is already in the frequency domain, which was its prime purpose.
When measuring noise and vibration in rotating machines, especially complex devices like automobile engines, it is very important to fully understand what is being measured and what analyses need to…
Normally when we are analysing a signal it is a purely real signal, that is it has no imaginary part. A classic example is of course a sine wave. When…
