We are using the third octave band filter at very low frequencies (~1Hz) and I noticed that the response of the filter could introduce very significant errors for short or transient signals. Looking a bit more in details at the function, the help says:
“For audio work ISO standards use a reference frequency of 1kHz not 1Hz”
Does that implies that for non-audio work, a reference frequency of 1Hz should be applied? If yes, is it possible to change this reference frequency in the dats function?
Dr Mercer replied…
Essentially there is no problem and no need to change the reference frequency provided you use Base 10 mode and not Base 2. Base 10 is the ANSI S1.11-2004 preferred scheme. (more…)
A simple tutorial that explains how to use the DATS Acquisition software to set up a Prosig P8000 to capture data from a CAN-bus. http://www.youtube.com/watch?v=XeAuntGW-O4
“How do I balance a shaft?” seems like a fairly straightforward question, but there are a number of things that we need to understand first. Here we look at a number of key concepts that need to be understood in order perform balancing.
What does balance mean?
Well broadly speaking to balance a shaft, mass must be added or removed at certain angles. The concept being that the centre of gravity and rotational centre of the shaft will be equal when the shaft is balanced. (more…)
A user has three signals captured using a triaxial accelerometer and asked “What is the simplest way to get the XYZ resultant from run-up file?” He had tried forming a resultant of the raw time histories, but didn’t fully understand the resultant time history.
Of course, the correct way of processing the data is to calculate the individual waterfalls from the x, y & z data and then calculate a resultant waterfall. (more…)
ODS = Motion of structure vibrating naturally (for example bridge vibration) or when excited by an unknown force (for example generator vibration). Prosig’s Structural Animation software performs ODS analysis.
A user recently asked…
[su_quote]I was hoping you can give me some way that I can create a plot with two different vertical (Y axis) scaling. I want to plot Principle stress and applied load vs. time on the same plot.
I want to show the principle stress increments on the left side of the graph and the load scale on the right side of the graph. I can do this with some other programs but cannot find a way to do it in DATS for Windows.
Transfer Path Analysis (TPA) provides the route of the noise or vibration through the structure, not just which sources cause the response, but the route taken. This is useful for developing and improving components like engine anti-vibration mountings or suspension anti-vibration mountings. (more…)
One of Prosig’s engineers was recently creating a complex worksheet application that required some complicated arithmetic to be performed on values calculated in the worksheet. Worksheet (or global) variables are ideal for this. The Variable Mods DPU also has an expression evaluator built in. Consider the following worksheet that takes a Named Element from two signals and sums them. (more…)
The digital tacho channel in a P8000 system offers better time resolution by dividing the main sample period by 16. However it is sometimes difficult to know what level the threshold should be set to so a facility to help you find the optimum level has now been added to the acquisition software. (more…)
The P8012, P8020 & P8048 can all be fitted with the 8440 CAN-bus/GPS card. Setting up the P8000 to capture CAN-bus data is extremely simple. In the following video, James…
Use the following sequence to get the Articulation Index (AI) vs rotational speed: Perform waterfall analysis on your noise signal (+ tacho). This gives you a standard waterfall display On…
I’m sure many users will have been in this situation. You need an analysis function, you know it’s in DATS, but you can’t remember where. One of the major strengths of the DATS package is the depth of analysis functions it provides. Unfortunately, when you have a deadline and can’t find the function that you want that isn’t much help. But assistance is at hand… (more…)
This article is the first in a series that will introduce two very important facilities that can be used when creating DATS worksheets – Named Elements and Global Variables. It is perfectly possible to perform simple measurement and analysis with DATS without knowingly using either of them. However, knowing how they work and what they can do, will lead to much more efficient and flexible worksheets. The first subject we’ll look at is Named Elements. (more…)
This is complete version of the video illustrating my recent article How To Measure Noise & Vibration In Rotating Machines. This video was previously published on the blog in 3 parts.…
http://www.youtube.com/watch?v=vZCKb4ikX1s This is the final part of our four part tutorial. This adds a report to the worksheet we developed in part 3.
![Read more about the article [Video] How To Calibrate Microphones & Accelerometers](https://blog.prosig.com/wp-content/uploads/2011/10/microphone-640-250.jpg)
![Read more about the article [Video] A Simple Capture, Analysis and Report (Part 4)](https://blog.prosig.com/wp-content/uploads/2011/06/videoTutorials-640-2501.jpg)
