Navigation:  Tutorials > Dynamic signal analysis tutorials > Torsional vibration > DEWESoft 7.0  data acquisition, processing, analyzing and storage software Rotational order extraction

To extract orders from a rotational vibration, we need to add the order tracking module. For the frequency source, we need to define the Torsional vibration module. For this, you select the module and Frequency channel (within the module if torsional vibration is used).

For this, you select the module and Frequency channel (within the module if torsional vibration is used). Next we need to define the Upper RPM limit and Lower RPM limit. This is used to reserve the memory for waterfall FFT. The waterfall will be drawn from the lower to the upper limit in the Delta RPM step . In this case, we will have (3000-0) / 50=60 steps of waterfall.

We choose to extract first three orders.

 

Now let's do some measurements. We have frequency and harmonic channels, therefore we can add the x-y display for displaying the orders. The OT_Frequency should be used as x reference (first chosen channel of x-y), and the H_1, H_2 and H_3 orders should be used as the y axis. Then we make a run down to observe the orders, where we can clearly see the peak at 1800 RPMs that we previously observed in the recorder being the first order of vibrations.

 

To see it even better, we can add the 3D graph. This graph can only show matrix channels. Order tracking has two of them - OrderFFT and TimeFFT, which can be used as the data sources. Now we can start our run up or run down. Since the color shows the amplitude at a certain frequency and RPMs, we need to carefully choose the amplitude scale to show the graph in a nice way. To see also the small amplitude values, the logarithmic y scale is recommended.