What Are dB, Noise Floor & Dynamic Range?
We are often asked what noise floor & dynamic range actually are. Most engineers are probably familiar with or have come across the decibel or dB as a unit of…
How Do I Upsample and Downsample My Data?
This post covers how to upsample and downsample data and the possible pitfalls of this process. Before we cover the technical details let us first explain what we mean by upsample…
What Are Vibration, Torsional Vibration & Shaft Twist?
When analyzing rotating shafts some terms are often confused. This post will attempt to explain the differences. So, what are vibration, torsional vibration and twist? What is Vibration? We measure at…
The Effect of the Nyquist Theory on Rotational Order Analysis
Nyquist theory is generally understood, but this understanding usually relates to time sampling and the conversion to the frequency domain. Rotational order analysis and the effect of the Nyquist frequency…
Does Prosig hardware support strain gauges? And which types?
I’m often asked whether the Prosig systems support strain gauges. And what configuration of strain gauge bridges are supported? The answer is all types of all configurations. (more…)
How to avoid a ground loop – It’s not only a problem with accelerometers
When using modern, high technology measurement devices one can often be tripped up by the simplest things. The most common is the ground loop. Time and again this issue rears…
Example of performing a Moving Average
This tutorial guides a DATS user through the steps required to perform a moving average on a given signal. The tutorial explains the concept of the ‘Integration Length’ and the ‘Output Interval Step’.
Initially a signal is required to perform the moving average on. In this tutorial a sine wave will be generated. A sine wave is generated using the parameters shown in Figure 1.
Speech Articulation Index – What Does It Mean?
There are many ways to calculate speech articulation index and each has its advantages in different applications. Prosig's DATS includes four methods for evaluating the Articulation Index as seen in the table…
Processing pump data – a classic case of amplitude modulation
When dealing with some vibration data from a pump, we observed some strange phenomena in the data. It turned out to be a classic case of amplitude modulation. Here we explain what that means.
Is it possible to connect the BNC outer to ground when using a P8000?
A question was recently posed regarding the grounding conditions of a BNC type input. The shield or outer of a BNC cable or connector is not connected to the chassis or ground. What would happen if it was connected to ground?
Automatic Reports Using The Intaglio Report Generator
https://www.youtube.com/watch?v=MWrDPpLh5-U
What is the maximum analysis frequency for a waterfall in DATS?
The maximum analysis frequency is always half the sample rate of the input signal.
So if your data is captured at 50kHz the maximum analysis frequency will be 25kHz.
Creating Order Plots Using The DATS Rotating Machinery Software
In this tutorial we will be creating order plots using waterfall and intensity displays using use the DATS.toolbox and Rotating Machinery Analysis option.
To begin, a noise, vibration or other signal of interest should be captured along with a tachometer signal.
In Figure 1 we have loaded a time series (in this case an acceleration signal) and a time series of a tachometer pulse train into the DATS software.
Making an Orbit Plot
A short video tutorial describing how to create an orbit plot using the DATS software https://www.youtube.com/watch?v=VP4esKwLuCg
How to use an Analogue Channel with Tachometer Signals on the P8000
When using an analogue channel input channel of a P8000, with a tachometer sensor, is it possible to utilise the tachometer processing functions as you would if you were using…
Sound Mapping Software Example
https://www.youtube.com/watch?v=KNZ3In5sisA
What is waterfall frequency spacing? And how does the DATS parameter ‘Requested Frequency Spacing’ work?
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…)
What is “waterfall smearing”?
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…)
Multiplane Balancing – Zero Imbalance or Specified Imbalance
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…)
Is it important to consider the cable resistance when using strain gauges?
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…
How should the bridge factor be selected when using strain gauges?
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…)
When should I use the ground connection on my P8000 data acquisition system?
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…
What engineering decisions are made by measuring a power spectrum?
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…)
What Is A Load 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… (more…)
How Do I Convert To Decibels?
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…)
