Sound, Vibration & Acoustics Digest #8
To welcome you to 2015 here's our latest collection of news articles, videos and other miscellaneous links on noise, sound, acoustics and vibration that have caught our eye over the…
To welcome you to 2015 here's our latest collection of news articles, videos and other miscellaneous links on noise, sound, acoustics and vibration that have caught our eye over the…
The intention of this article is not to present any new scientific theories or ground breaking techniques, but to introduce new users to hammer impact testing and remind seasoned technicians of a method…
Chip/crisp packets, smartphones, the spooky sounds in space and the absolutely fascinating Diana Deutsch Speech to Song Illusion; welcome to our latest digest Extracting audio from visual information https://newsoffice.mit.edu/2014/algorithm-recovers-speech-from-vibrations-0804Algorithm recovers…
Our articles on how to measure resonance and natural frequency are always amongst our most popular posts. This isn't surprising considering what an important concept this is to the measurement…
https://www.youtube.com/watch?v=uGWQELrZn_o
https://www.youtube.com/watch?v=W-Dcd3k2r2I
https://www.youtube.com/watch?v=KNZ3In5sisA
https://www.youtube.com/watch?v=3iAfvjMWE6U
https://www.youtube.com/watch?v=TtfKx6P0qNU
There's a distinct coffee "flavour" to our latest digest with two stories related to the bean. We hope you enjoy the articles we've found and as always please leave your…
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…
If you are visiting the Automotive Testing Expo 2014 China in Shanghai (September 15th - 17th) then please come along and see us at stand 9013. You will able to see all the…
Let us try to understand what waterfall frequency spacing is. Waterfall frequency spacing is the gap between spectral lines in an FFT plot.
For example, if you had an analysis frequency of 0Hz to 100Hz and 100 spectral lines, then Frequency Spacing is 1Hz.
So why is there a ‘Requested Frequency Spacing’ and an ‘Actual Frequency Spacing’? (more…)
When analysing a waterfall or performing order analysis it is important to consider the frequency resolution or the frequency spacing.
There is often a desire to increase the resolution to finer and finer detail. But that is a process of diminishing returns, and actually fraught with danger. And that danger is waterfall smearing. (more…)
Prosig is pleased to announce that it has become part of Condition Monitoring Group (CMG) Limited. Prosig Limited will retain its operation in Fareham, Hampshire and will continue to operate with…
In the DATS Multiplane Balancing Software, there are two options, optimise for ‘Zero imbalance’ or optimise for ‘Specified imbalance’, but what is the objective of these two options?
(more…)
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…
The cable resistance can be a significant factor in the accuracy of the overall measurement. It is very important indeed to consider this point. Prosig software allows the cable resistance…
The number of active arms in a strain gauge Wheatstone bridge is known as the bridge factor.
As a simple guide when selecting bridge factors the following rules apply; (more…)
I hope you like our latest collection of news, articles and videos from the world of acoustics, vibration and analysis. After a very acoustics biased last edition we've dedicated this…
The ground connection should be used if an issue has been observed in measured data, such as significant electricity supply (50Hz or 60Hz) distortion or significant noise. It must be attached…
I hope you like our latest collection of news, articles and videos from the world of acoustics, vibration and analysis. This issue of the digest is very "acoustical" and includes…
By power spectrum we are talking about an ASD (Auto Spectral Density) or PSD (Power Spectral Density). In fact PSD is often used when really ASD would be more correct.
Taking any signal and performing a frequency analysis using an ASD or a PSD will give the energy over a range of frequencies. (more…)
When engineers talk about the ‘Load Spectrum’ what do they mean?
There is no simple answer, simple terms like load and spectrum can be used in different situations and therefore to mean different things. However the most common definition of load spectrum is as follows… (more…)
Much confusion revolves around linear and non-linear numbers. The following outlines the mathematical process to convert from a number expressed in dB to a linear quantity. How do we convert to decibels and back again? (more…)