Wednesday, August 14, 2019

Why I love using Sonus Vue Pro Desktop Software for Sound Analysis!

By Drew Walts ARP-1 SME, LV2 ASU, LV2 IRT

Ultrasound has been around for almost 50 years now, but we are just getting into understanding the true abilities of Ultrasound Test Equipment. Over the last 20 years, units have come with the ability to record sound waves. Initially companies were recording sound waves to compare the sound images and decibels, but now we at IRISS are helping to advance the analysis of sound waves to the next level. Long gone are the days of using an ultrasound unit just for trouble shooting, trending, or lubrication assistance. Today we can using it to determine so much more. For example: stray voltage, loose connection in the motor junction box, inner race, outer race, cage, or ball pass fault conditions in a motor.

When it comes to electrical inspection, we can do the same. However, the key to all of these is the use of the Time Signal Screen (Time Series). Here is a great explanation I recently sent to someone asking why our platform was superior to the one they are currently using…which I myself had previously used for years:

We can analyze soundwaves in a Time Signal (Time Series) screen that will allow us to find harmonics into the thousandths of a second, which is important when looking for electrical faults such as Corona, Treeing, Tracking, and Arcing. These will present with a .016 or .017 second interval (.0166666666667 actual value rounding up or down give us these 2 values) which is the conversion of a 60 Hz Harmonic into a time-based interval. Fault conditions like delamination of windings and loose connection will show a 120 Hz harmonic which converts to .008 (.0083333333333 actually value) while dirty power will generate intervals in a range of 121 – 122 Hz (.0082644628099174 to .0081967213114754).

With this capability, we can ensure the inspector is recording a sound wave that they will be able to find the harmonics even if they have nothing showing up in the Frequency Spectrum (FFT). This is just an example of why it is important for ultrasound analysis to determine what the interval of occurrence is using Time Signal vs Frequency spectrum, since critical angle cannot always be achieved during electrical inspection. From there, the inspector will look at the amplitude from peak to peak and see the difference that each anomaly will present. Much like an EKG, each of these events will have a distinct sound pattern that can easily be identified to help the inspector determine the fault condition simply by using this software.

Time Signal is the easiest of the views to see harmonic occurrences for most people. With the loss of signal when critical angle cannot be achieved, the frequency spectrum will not show any harmonic indications. This is much like driving a car over the top of a mountain while listening to the radio. As you start going down the backside of the mountain, you are no longer in line with the critical angle of the transmission and start to lose some of the signal. You may still be able to hear some of the song, but the quality of the signal is poor. The Time Signal is still able to show the harmonic intervals since it is a direct representation of the incident energy, whereas the frequency spectrum is a conversion of the time signal into a frequency spectrum. If the critical angle isn’t achieved, the harmonics can be lost and will not appear in the frequency spectrum screen when analyzing the sound wave. This is why being able to look down to a thousandth of a second is so important when using the time signal screen.

We also have the ability to use a spectrogram, which is a colorized mapping of the amplitude to show the frequency of the occurrence in time and frequency. It can then be run in the spectrogram analysis which allow for the exact determination of both these values in 2D. But the most amazing screen is the 3D Spectrogram which takes not only the time and frequency, but the amplitude of the sound wave as well. It can then map it in a 3D plot that can be rotated 360° to view at different angles, giving the inspector a stunning visual for using in their reports.

With so many additional faults being determined that can be detected using Time Series and Frequency Spectrum analysis of ultrasound sound waves, I look forward to the day that ultrasound will have its own Illustrated Table Chart. This will only happen, however, if ultrasound users share their findings like I have in this article and with the use of Sonus Vue Pro software as well. So, lets advance the science behind the analysis of ultrasound.

Contact me a d.walts@iriss.com and send me your sound waves and I will run them through our software and show you the difference in what Sonus Vue Pro Desktop can do.

Learn more about Sonus Vue Pro Software

Watch this video on how Ultrasound can improve your Condition-Based Maintenance Program!