What is Auto Spectral Density?

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. (more…)

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Exporting DATS datasets in non-linear format

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. (more…)

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The end for Windows XP. Are you ready?

Microsoft has recently announced that security updates and patches for its Windows XP operating system will end from 08 April 2014.

http://www.microsoft.com/en-gb/windows/enterprise/endofsupport.aspx

Many organisations are now having to update older PCs and laptops to Windows 7 or Windows 8. (more…)

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Rotor Runout Measurement

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… (more…)

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What Type of Accelerometer Should I Use? IEPE, Charge or Bridge-based?

What type of accelerometer should I use? What are the advantages/disadvantages of a charge mode accelerometer, an IEPE accelerometer and a bridge based accelerometer?

There are so many types of accelerometer that is often difficult to know what type of accelerometer to use. 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. (more…)

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Relative signal levels of a sinusoid with and without background noise

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.

Spectrum level of 35Hz sinusoid
Fig 1: Spectrum level of 35Hz sinusoid

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