Rotational Analysis with no Tachometer Data
The identification of cyclic events in rotational analysis is often key to identifying problems. It is good practice to use a suitable sensor for capturing rotational speed. However, this is…
titanium and steel gears and cogwheels
Analysis of Dynamic Engine Vibration – Angular Vibration in High Performance Engines
The analysis of dynamic engine vibration and the accurate measurement of angular vibration is a non-trivial task, as a more in-depth analysis of boundary conditions reveals. Tools for engine vibration…
Tire background texture
Using Source Contribution Analysis to analyze complex structural dynamics issues
Using Source Contribution Analysis (SCA) and Structural Animation (STA) in the DATS software for the analysis of complex structural dynamics This post uses Source Contribution Analysis (SCA) techniques and a…
Vehicle AC
Analysis of Airflow Instabilities in HVAC units
HVAC (Heat Ventilation Air Conditioning) units are devices used in various applications, such as cars, buildings, aircraft etc. They facilitate the transport and conditioning (heating, cooling, changing of humidity) of…
Three Methods For Analyzing Vibration In Rotating Components
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…
The Intelligent Way To Sort, Extract & Analyze Signals
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 some of the unique features of Prosig’s DATS software. It also shows the power and flexibility of the new DATS V7.0 worksheets.
Vibration Monitoring Phase Measurement And The Tacho Signal
Any 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 phase for vibration monitoring. Most vibrations on a rotating machine are related to the rotational speed so it is clearly important to have a measure of the speed, either directly or as a once per revolution tacho pulse. A question sometimes arises as to whether a once per revolution tacho reference signal is needed to measure phase. Is it possible to get phase if we only have a speed signal? This note gives some insight into those questions.
Actually the question that should be asked is – “Can we measure a meaningful phase, for use in vibration monitoring, if we only have a speed signal as well as the vibration signals?”
Orders v Time – Comparing Overall Levels
By 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 time (Orders from Hopping FFT) rather than as a function of speed (Waterfall). This is very useful when analyzing a complete operational cycle which includes run ups, rundowns and periods at operational speeds.
