A long-standing customer brought along his power station turbine test rig so that we could give the P8000 hardware and DATS software a good workout. Here’s a video of the rig in action. Watch this space for some data and…

A long-standing customer brought along his power station turbine test rig so that we could give the P8000 hardware and DATS software a good workout. Here’s a video of the rig in action. Watch this space for some data and…
In this post we will first look at how to process data from rotating machinery. Then we will focus on shaft or gear train twist. Let’s look at 3 different ways to measure and analyse rotating shafts. Each one has…
A method to identify subjectively objectionable disturbances (e.g. piston slap, valve tick,… etc) in internal combustion engines
When performing frequency analysis of vibration data for any application the resultant spectrum has both amplitude and phase components, therefore the phase component represents half of the information available and can provide a valuable insight into the causes of the…
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.…
Are you interested in measuring torsional vibration? Need to measure shaft twist? Worried about rotational jitter? Don’t worry, we’ve got it covered. Here we have gathered together our most popular articles on the subject of torsional vibration to give you…
The term synchronous data is usually applied to vibration or acoustic data that is captured from an item of rotating equipment at regularly spaced angle intervals as distinct from regularly spaced time intervals. The rotating part could be an engine,…
In this article we will look at the basic steps needed to measure noise & vibration in rotating machines. We won’t look in great detail at some of the techniques involved – we deal with these elsewhere on the blog. This material…
Creating a good quality tachometer signal is one of the hardest parts of analyzing rotating machinery. So what happens if we have missing tachometer pulses? The data looked great until we tried to perform some in-depth torsional vibration analysis. And…
This note is based on a real requirement presented to Prosig by a prospective user. It’s the sort of challenge that we relish. This case is a great example of a real-world signal processing requirement and also great test of…
Knowing how to measure torsional vibration is of key importance in the area of vehicle development and refinement. The main contributory source is the engine where periodically occurring combustion cycles cause variation in the crankshaft rotary vibration. This vibration is…
Using Prosig’s P8000 series data acquisition system with DATS signal analysis software, torsional analysis (crank shaft jitter) was performed on an automotive engine attached to an engine dynamometer. The significance of this is that only one tachometer channel was required…
Prosig were recently involved in the validation of a closed loop control system for an automotive pump supplier. The customer has a large number of test cells, each test cell has 8 pumps continually on test. Each pump is instrumented…
With shafts, gears and the like, the general method of determining the rotational speed is to use some form of tachometer or shaft encoder. These give out a pulse at regular angular intervals. It we have N pulses per rev…
A shaft has been instrumented with two shaft encoders, one at each end. Each shaft encoder gives out a once/rev pulse and a 720 pulses/rev signal. Each signal was digitised at 500,000 samples/second. The objective is to measure the twist…
In a recent article we described how the Prosig P8000 hardware and DATS software had been used to help Dalmeny Racing diagnose a problem with an exhaust bracket on their Formula Ford racing car. Whilst the car was instrumented for…
The following article was written in response to a question from a visitor to the website. The gentleman in question had been reading some of the Prosig signal processing articles and had the following question. Dear Sir, It was interesting…
When working with audio signals a common requirement is to be able to equalise, cut or boost various frequency bands. A large number of hardware devices on the market provide this capability. The key aspect is that such filters are…
The measurement of torsional twist, or the twist angle, between two points along a shaft or through a gear train may be derived from a pair of tacho signals, one at each end of the shaft. Typically the tacho signals…
It is sometimes necessary to perform high pass filtering to eliminate low frequency signals. These may arise for instance from whole body vibrations when perhaps our interest is in higher frequency components from a substructure such as an engine or…