Navigation:  Tutorials > Dynamic signal analysis tutorials > Order tracking > DEWESoft 7.0  data acquisition, processing, analyzing and storage software Measurement

Now we can make some measurements. The order tracking math doesn't create any display on its own, so we need to define the display manually. I have added the analog and digital meter for rotation speed and recorder for rotation speed and vibration value just to be able to see the run up. Next we can use the xy recorder, where the x axis should be OT_Frequency and y axis can be used for the harmonic components (in our case Vib H_1, Vib H_2 and so on). We need to select the "Single X axis" mode of the recorder and it is recommended to use the "Real data" display type to show every point of the run up on the xy graph.

Next, I have added the frequency plot for Vib signal to be able to see the current frequency speed, and below, I have added the 3D graph. Then select either TimeFFT, if we want to display the x axis in frequency or OrderFFT channel, if we want to display the x axis in order. It is recommended to select logarithmic scaling and two to three decades of amplitude resolution (if we have 1 g maximum, we choose 0.001 g as minimum) to show the amplitude in nice colors. Less dynamic (two decades on the picture below) will emphasize the peaks more, while more dynamic will reveal smaller components of the run up.

 

We can use the xy plot to display the amplitude of certain orders compared to the frequency (rotation speed) of the machine. In the same manner we can also display the phase to create the Bode plots. If we plot real vs. imaginary, which are used in the x-y graph, we can create a Nyquist plot as seen on the picture below.

There is also a nice way to see the current time data in the x-y plot. We can select the Order tracking Graph type in the x-y section, then we select any channel that is defined in the order tracking and we can see the periods aligned with the zero pulse of the encoder or the tacho signal in time. We can select any number of periods and choose to display current period, averaged number of periods or show the data with persistence .

 

If we have two displacement measurements on the shaft axis, we can display the shaft movement in the orbit plot. We can  select the Order tracking mode and Display Current or Averaged data, or show orbits with persistence. We can also display the harmonics, like shown on the picture below. The yellow dot shows the position of the zero pulse of the angle sensor.