If you are visiting the SAE 2013 Noise and Vibration Conference and Exhibition in Grand Rapids (May 20th – 23rd) then please come along and see us at booth 409. Ken Goward & John Mathey of Prosig USA will be at the show along with Adrian Lincoln from the Prosig in the UK. They will be more than happy to show you all the latest versi [...]
Come and see Prosig at SAE 2013 Noise...
If you are visiting the SAE 2013 Noise and Vibration Conference and Exhibition in Grand Rapids (May 20th – 23rd) then please come along and see us at booth 409. Ken Goward & John Mathey of Prosig USA will be at the show along with Adrian Lincoln from the Prosig in the UK. They will be more than happy to show you all the latest versi [...]
A Different Way Of Averaging – ...
Assuming one wants a frequency spectrum from an acquired time measurement, it is generally accepted that averaging of a signal in the time domain is not very useful due to the randomness of the start of the time block used to calculate the Fourier transforms to be averaged. If there is a way to synchronize the start of the time block to a pe [...]
10 More Cool Engineering Videos
Our previous collection of cool engineering videos in 2010 proved so popular that we just had to make another list. So here we present another 10 really cool engineering videos. These videos highlight just why we at Prosig enjoy working with engineers in so many different fields. And why we ourselves took up engineering in the first place.
Yo [...]
Quantifying Signals – Peak, Pea...
Anytime you measure something which is changing with time, there are multiple ways to quantify the signal. For the purpose of this discussion, we will be talking about how to describe the signal in the time domain.
There are several ways to describe what the time signal is doing. Perhaps the easiest to understand are the Peak and the Peak-to- [...]
What Is Hammer Impact Testing?
This is often also known as Modal Testing. It is a method of testing that allows us to calculate the natural frequencies (modes), modal masses, modal damping ratios and mode shapes of a test structure. This is commonly done using either impact hammer testing or shaker testing. Here we are going to deal only with impact hammer testing.
In theo [...]
What Can I Do About Spikes In My Data...
Whether you call them spikes, glitches, anomalies or data dropouts, these phenomena have been a problem to engineers ever since they started recording data. There are any number of reasons why these problems occur.
Sometimes it may be possible to repeat a test, but more often a busy engineer doesn’t have time or the test item has long g [...]
Engine Model Being Put Through Its Pa...
Our engine model demonstrator being put through its paces. Runups, rundowns and ‘overclocking’
What Are AC and DC Coupling?
This is an important subject to understand when working in the signal processing field.
First, what is coupling?
Quite simply, coupling is the transfer of energy from one medium to another, for example, from a metallic wire to an optical cable. This transfer of energy may be desirable or undesirable.
What is DC coupling?
DC coupling allows bo [...]
Come & see Prosig at Testing Exp...
Prosig will be at Automotive Testing Expo North America from today, October 23rd, until October 25th 2012. Among the hardware and software on display will be some of the latest developments to Prosig P8000/DATS mobile systems. These include
CAN-bus/GPS capabilities including CAN CCP
new higher density channel counts
new RapidResults technolo [...]
Understanding & Measuring Noise
There are many reasons to measure and analyze noise. It may relate to legislation or regulations that limit noise in certain environments, we could be using the noise to investigate a related issue or maybe simply improving the noise of a vehicle or other product.
Prosig are experts in measuring and analyzing noise. Follow the links below to [...]
What is Resonance? (Part 2)
This article is a follow on from What Is Resonance? (Part 1) and answers some of the issues not covered in that post.
How do you find the resonant frequency in the real world? What do you do when there is a situation with multiple peaks in the frequency domain data? How do you know the frequency you have found is a resonant frequency?
To answ [...]
2nd Annual Prosig / Portsmouth Univer...
The 2nd Annual Prosig Prize for Engineering at Portsmouth University has been awarded to Ashley Stehr for his project “Developing an engineering mechanism to reduce the effects of rapid rotational motion caused by the shocks inherent with high speed craft”. Ashley is in his third year studying for an MSc in Mechanical Engineering. [...]
Waterfall Analysis: Frequency Spectru...
This article addresses two basic approaches to analyzing rotating machinery during transient (sweeping rpm) conditions. The first is the traditional method which uses Frequency (FFT) Spectrum analysis at target rpm values throughout a run up or a coast down condition. As discussed in a previous article on frequency resolution and smearing i [...]
Building a new test model
Recently, we decided it was about time we had a new model for testing, training and demonstrations. Specifically, we wanted something that would allow us to test the full capability of the standard tacho channels available on the P8000 systems and the optional advanced tacho card. Ideally, we would have obtained a V8 engine or a small turbine [...]
Vibration Condition Monitoring Doesn&...
Have you ever wondered if there is a vibration condition monitoring system that can be installed anywhere and then monitored from anywhere else? Even on your smartphone? Well, there is. The following article explains how Prosig’s PROTOR-mobile vibration condition monitoring system can offer just such a solution.
Sometimes vibration issu [...]
In-situ balance of an Open Cycle Gas ...
A vibration problem arose at an Open Cycle Gas Turbine. Following an outage on the four gas turbines and two SSS[1] clutches, the machine returned to service with unacceptable vibration levels on some generation runs resulting in a significant loss of commercial operation.
The OCGT consists of two sets of two Rolls Royce ‘Avon MK 1533’ gas ge [...]
Wide Band Integrators – What Ar...
For some time now it has been conventional ‘wisdom’ that using time based digital integration may cause amplitude errors in the result and that these get worse as the frequency increases. As a result of this, integration using Omega arithmetic has been prevalent by using Fourier Transforms of the signal. This, of course, remains a valid appro [...]
Noise & Vibration Analysis: Back...
Sometimes it doesn’t hurt to revisit some of the basic building blocks that form the foundation of what we do. And so we have gathered together a few of our most popular past articles that deal with the fundamental aspects of measuring and analysing noise and vibration data. Please leave a comment if you have a favourite. Or, if you thi [...]
Where Does The Noise Come From?
When one thinks of noise in a signal it is generally associated with having been added in some way to the amplitude of a signal. This is not always the case.
The two sinewaves shown in Figure 1 appear similar with the same frequency and amplitude except that the top one appears to have some noise or distortion present.
Figure 1: Two sinewave [...]
Waterfall Analysis: Frequency Resolut...
When measuring noise and vibration in rotating machines, especially complex devices like automobile engines, it is very important to fully understand what is being measured and what analyses need to be performed on the resulting data. Even the most sophisticated measurement systems will not produce meaningful results if used incorrectly. The [...]
New Version Of DATS Out Now – V...
The latest version of Prosig’s DATS software was released today and is available to download from the Prosig Support web pages. Read on to find out about some the new features… (more…)
Understanding the Importance of Trans...
When monitoring vibration on large gas or steam turbines and generators with fluid-film bearings, the relative movement of the shaft within the bearing is typically measured by a pair of shaft proximity (eddy current) transducers. Data from these transducers is used to produce a variety of plots on a condition monitoring system including orbi [...]
Testing Times : Why & How We Mea...
We’re going to look today at some of the practical aspects of testing and consider why it’s important that you should measure and, more importantly, understand the noise and vibration of your products
The current global economic situation means that times are tough for everyone. It’s now that you need a competitive edge; tha [...]
Why is the microphone pressure refere...
This seemingly simple question is actually quite fundamental. To answer the question we need to consider sound intensity. Now sound intensity is defined as “the average rate of flow of energy through a unit area normal to the direction of wave propagation”. The average rate of flow of energy is energy per second which we recognise as power [...]
Mari Aerotech To Attend Automotive Te...
Prosig’s Indian distributor, Mari Aerotech, will be exhibiting at Automotive Testing Expo India 2012. The conference runs on 6th, 7th & 8th March 2012 at Chennai Trade Centre.
Automotive Testing Expo India was launched with massive success last year in Hyderabad, Automotive Testing Expo India and will move to Chennai in 2012, one of [...]
