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 it to a very good earth point (like a steel pipe or foundation)
It should be noted that sometimes connecting the ground cable to earth can actually make matters worse. It depends on the situation.
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. Continue reading What engineering decisions are made by measuring a power spectrum?
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… Continue reading What Is A Load Spectrum?
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? Continue reading How Do I Convert To Decibels?
The Auto Spectral Density or Auto RMS spectrum analyses uses Fourier Transforms to process optionally overlapped sections of the input data. The result of each Fourier analysed section is called a periodogram. We then process all the resulting periodograms to produce a spectral result. Continue reading What is Auto Spectral Density?
To complement our recent post on Exporting DATS datasets in non-linear format here is James Wren demonstrating the method.
The following tutorial shows in detail how to use Prosig DATS to export data in a non-linear format.
DATS stores all data in linear format. When you export data you are exporting the raw stored data. Therefore, to export data in a non-linear fashion we must convert the data to non-linear scale (dB for our example) and then export to the desired format, in this case CSV. Continue reading Exporting DATS datasets in non-linear format
Microsoft has recently announced that security updates and patches for its Windows XP operating system will end from 08 April 2014.
Many organisations are now having to update older PCs and laptops to Windows 7 or Windows 8. Continue reading The end for Windows XP. Are you ready?
Prosig’s DATS Software includes an optional add-on package for rotor runout measurement. Runout may consist of two components – Mechanical Runout and Electrical Runout. You can read more about runout on prosig.com here – Rotor Runout Measurement.
We are often asked exactly what analysis and information is included The purpose of this post is to show some of the screens and reports from the Rotor Runout Measurement package. So here goes… Continue reading Rotor Runout Measurement
What sample rate should I use if I am measuring whole body vibration?
Strict ISO8041 compliance imposes a minimum sample rate of 900 samples per second. This ensures the amplitude and phase characteristics of the applied weightings meet the required criteria. To take account of the anti alias hardware filter we would recommend 1200 samples/second. If non-strict compliance is used the minimum sample rate is 300 samples/second.
ISO2631-1 recommends a minimum data duration of 227 seconds. However, for greater reliability, 600 seconds is now considered essential. That is, a 600 second or longer signal will be more representative and will provide better quality results.