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
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
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
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
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.
What are the advantages/disadvantages of a charge mode accelerometer, an IEPE accelerometer and a bridge based accelerometer?
An IEPE accelerometer will have a high pass filter at about 5Hz. The charge type will, by it’s nature have what is effectively a high pass filter at about 0.1Hz. Therefore neither type will show DC levels. The charge type will usually have a lower frequency bandwidth than the IEPE type. Charge accelerometers can be used at higher temperatures however. Continue reading
A video that explains how to set up the DATS Data Acquisition software to perform captures at specific, scheduled times.
The DATS Modal Analysis software consists of Hammer Impact Testing, Modal Analysis & Structural Animation (often referred to as Operational Deflection Shapes or ODS and Running Modes). Having measured and analysed your data the Structural Animation software allows you to visualisation your structure under certain operating conditions. These visualisations can then be saved as AVI files. This video shows you how…
In the process of looking at some order data, a question about the accuracy of the measurement of the signal level of discrete frequency signals which were close to the general noise level. To answer this question, a small DATS worksheet was created which generated 2 signals. The first signal was a 35 Hz sinusoid which, by itself the spectrum level was measured to be approximately -9 dB (ref 1 V) as seen in Figure 1.