Operating Deflection Shape (ODS) analysis is a method used for visualisation of the vibration patterns of a machine or structure caused by unknown operating forces. This is different from the study of the…
Various human body vibration measurements and assessments are defined in the ISO2631, ISO5349, ISO6954 standards and also in the EEC vibration directive 2002/44/EC. These assessments are based on the analysis…
In our previous post on this subject we briefly looked at how we can use the detailed design information of bearings and gearboxes to look for specific fault conditions by collecting vibration information and analysing their frequency spectra. Amplitude modulation of the vibration signatures is common and we have seen how this causes side-bands to be present in the frequency domain.
Bearings and gearbox vibration are fundamental issues for rotating machines in many industrial applications. These are critical components and, as such, any failure can prove expensive in both repair cost…
After finding the natural frequency of a system, what could be done to stop or reduce the systems resonance being excited? Basically put, how do we avoid resonance This is…
In this post we will first look at how to process data from rotating machinery. Then we will focus on shaft or gear train twist. Let's look at 3 different…
Have you reached the limits of your Sound Level Meter? Do you need to progress to the next level? Prosig have a range of systems that can increase your noise…
Prosig and their partners, SV Japan, will be holding a two-day training seminar for current and new customers in Hiroshima on Tuesday 3rd and Wednesday 4th December 2013. Subjects covered…
A method to identify subjectively objectionable disturbances (e.g. piston slap, valve tick,… etc) in internal combustion engines
Picture the scenario; you have captured some noise & vibration data from a rotating machine. Typically, this might be noise in a vehicle cabin, but could have been anything from…
When performing frequency analysis of vibration data for any application the resultant spectrum has both amplitude and phase components, therefore the phase component represents half of the information available and…
In the previous two articles (What Is Resonance? (Part 1) & What Is Resonance (Part 2)) in this series we have looked at how we can identify a resonant frequency.…
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…
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…
This is often also known as Modal Testing. It is a method of testing that allows us to calculate the natural frequencies (modes), modal masses, modal damping ratios and mode shapes…
Whether you call them spikes, glitches, anomalies or data dropouts, these phenomena have been a problem to engineers ever since they started recording data. There are any number of reasons…
Here are two videos on a relatively simple, but sometimes misunderstood procedure – how to calibrate microphones & accelerometers (more…)
http://www.youtube.com/watch?v=vZCKb4ikX1s This is the final part of our four part tutorial. This adds a report to the worksheet we developed in part 3.
http://www.youtube.com/watch?v=gvwwfCampas Today we have the third of our four part tutorial. Here we show how to quickly build a worksheet to analyze the data we captured in parts one and…
http://www.youtube.com/watch?v=4ejGBG5ImfY Part two of the four tutorials showing a simple setup to capture, analyze and produce a report using Prosig’s DATS software and P8000 hardware. This part deals with setting…
http://www.youtube.com/watch?v=dGRzTxzUWfE The first part of a series of four tutorials showing a simple setup to capture, analyze and produce a report using Prosig's DATS software and P8000 hardware. Part 2…
Over the past few years it has been impossible to ignore the rise of social networking. Sites such as Facebook & Twitter have come to dominate the Internet to such…
Creating a good quality tachometer signal is one of the hardest parts of analyzing rotating machinery. So what happens if we have missing tachometer pulses? The data looked great until we tried to perform some in-depth torsional vibration analysis. And now we no longer have the component or vehicle to retest it. Do we have to scrap the whole test? Was all that time wasted? Not necessarily…
As you may know Prosig have recently released a GPS module for their popular P8000 series of data acquisition systems. The GPS module adds the ability to record accurate position information alongside all of the normal measurement channels. This is a highly useful capability and enables an engineer to easily correlate measured results with vehicle position and behaviour at the time. It also makes it simple to extract data based on position on a test track or road course.
Knowing how to measure torsional vibration is of key importance in the area of vehicle development and refinement. The main contributory source is the engine where periodically occurring combustion cycles cause variation in the crankshaft rotary vibration. This vibration is transmitted to and modified further by other components in the powertrain such as the gearbox and by other equipment driven off the drive belt or chain. Additional torsional vibrations are also likely to appear downstream at the drive shafts and wheels.
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