rotating machinery Archive
Video: Noise & Vibration From Rotating Machines
Posted on October 4, 2011 | No CommentsThis 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....
How To Analyze Noise & Vibration In Rotating Machines
Posted on August 9, 2011 | 3 CommentsIn this article we will look at the basic steps behind a simple rotating machinery study. We won’t look in great detail at some of the techniques involved – we deal with...
Do Missing Tacho Pulses Mean The End Of The Road For Your Test?
Posted on September 20, 2010 | No CommentsCreating a stable, good quality tacho signal can be one of the hardest parts of analyzing rotating machinery. So what happens if our carefully designed and implemented tacho misses a...
PROTOR Vibration Condition Monitoring System Installed in Three Thermal Power Plants in Spain for Iberdrola
Posted on August 31, 2010 | No CommentsIBERDROLA has launched a renewal plan for the existing condition monitoring systems in their plants in Spain. This plan will be implemented gradually and PROSIG was selected to install their...
Aliasing, Orders and Wagon Wheels
Posted on June 29, 2010 | No CommentsThese days most people collecting engineering and scientific data digitally have heard of and know of the implications of the sample rate and the highest observable frequency in order to...
Vibration Condition Monitoring Using Your Android Smartphone
Posted on May 14, 2010 | No CommentsEver been lying on the beach and begun to wonder about the state of your LP turbines? Or out on business and anxious to know if that troublesome exciter bearing...
Measurement And Analysis Of Torsional Vibration
Posted on October 17, 2008 | 13 CommentsTorsional 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...
Shaft Displacement Measurement Using A PROTOR System
Posted on June 4, 2008 | 5 CommentsShaft displacement is an important vibration measurement for rotating machines. Shaft displacement is usually monitored by non-contact shaft displacement probes such as eddy-current probes. These probes produce a voltage proportional...
Vibration Monitoring Phase Measurement And The Tacho Signal
Posted on March 4, 2008 | 5 CommentsAny vibration signal may be analyzed into amplitude and phase as a function of frequency. The phase represents fifty percent of the information so it is most important to measure...
Orders v Time – Comparing Overall Levels
Posted on October 23, 2007 | 4 CommentsBy combining a speed signal with a data signal and using the Short Time FFT algorithm (Hopping FFT), it is possible to extract order data directly as a function of...Measuring Torsional Crank Shaft Jitter
Posted on June 24, 2007 | No CommentsUsing Prosig’s P8000 series data acquisition system with DATS signal analysis software, torsional analysis (crank jitter) was performed on an automotive engine attached to an engine dynamometer. The significance of...
Updated Protor System For Ringhals, Sweden
Posted on October 3, 2006 | No CommentsProsig installed a PROTOR system at the Ringhals1 reactor in Sweden in 1992. This system was based on the PROTOR2 level of hardware and software and consisted of a Sun...Torsional Vibration, Tacho Pulses And Aliasing
Posted on January 12, 2006 | 3 CommentsWith 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...
Analyzing Shaft Twist And Repairing Damaged Tachos
Posted on October 19, 2005 | 1 CommentA 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...
Phase Between Signals
Posted on August 9, 2005 | 4 CommentsThe 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...Average Waterfalls Or Average Orders?
Posted on June 14, 2005 | No CommentsOne would expect that averaging waterfalls and then extracting orders would give the same result as extracting orders from individual waterfalls and then averaging them. This is not the case.
Measuring Torsional Twist & Vibration Along a Shaft or Through a Geartrain
Posted on May 15, 2002 | 3 CommentsThe measurement of 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...Frequency, Hertz & Orders
Posted on February 3, 2002 | No CommentsThe most common form of digitising data is to use a regular time based method. That is data is sampled at a constant rate specified as a number of samples/second....
High Pass Filtering And Tacho Signals
Posted on June 6, 2001 | 2 CommentsIt is sometimes necessary to pass a signal through a high pass filter to eliminate low frequency signals. These may arise for instance from whole body vibrations when perhaps our...
