Condmaster Ruby Add-On EVAM with Condition Manager, HD ENV
The SPM Vibration MOD135 is a Condmaster Ruby add-on with EVAM (Evaluated Vibration Analysis Method) offered as an analyzing function. The method generates three sets of machine condition data:
- Condition parameters, which are measured and calculated values describing various aspects of machine vibration
- Vibration spectra where significant line patterns are found, highlighted and evaluated with the preset fault symptoms
- Machine specific condition codes (green - yellow - red) and condition values, based on a statistical evaluation of the condition parameters and symptom values
For each measuring point, the user can make an individual selection and define the type of data best suited for the surveillance of an individual machine. Alternatives include:
- Enveloping HD ENV
- Time synchronous averaging
- Band values and averaging of measurement results for improved alert reliability; The number of false alerts is minimized by filtering out randomly high readings caused by disturbance
Condition parameters are measured for a selected frequency range. They can be individually activated and are shown in measuring result tables and as diagrams. Available are:
- VEL - RMS value of vibration velocity
- ACC - RMS value of vibration acceleration
- DISP - RMS value of vibration displacement
- CREST - Crest value, difference between peak and RMS
- KURT - Kurtosis, the amount of transients in the vibration signal
- SKEW - Skewness, the asymmetry of the vibration signal
- NL1-4 - Noise level in the four quarters of the frequency range
Peak and peak-to-peak values are shown in the unit selected for the time signal. Values can be displayed in dB according to European or US Navy standard as well as user-defined. For easy pattern recognition in spectra, EVAM supplies a range of ready-made 'fault symptoms'. These are instructions to highlight a spectrum line pattern and display the sum of the lines' RMS values as a symptom parameter (which can be evaluated and trended). Most symptoms are automatically configured by using the rpm as a variable. Suitable symptoms and symptom groups are selected in Condmaster Ruby when the measuring point is set up. As an alternative, cepstrum analysis can be used for gearboxes. In Condmaster Ruby, alert limits can be set on all active parameters. Once measuring results are collected, an EVAM 'criterion' can be created that compares new parameter values with the statistical mean value and displays a dimensionless condition value against a green-yellow-red scale.
Phase is a time delay expressed in degrees of rotation. Leonova or Intellinova calculates the time delay between the passage of the tachometer pulse and the peak of the frequency component of interest from the vibration transducer at the speed of rotation. The value presented is a relative angle, not an absolute because there is no compensation for phase lag in the transducer or the electronic circuits. Phase differences in between two signals can also be displayed.
HD ENV is capable of detecting machine problems at a very early stage, which are generally hard to find in good time with non-enveloping technologies - the method utilizes cleverly engineered algorithms for digital signal processing to obtain optimal data for trending purposes.
Order Tracking is primarily used for analysis on variable speed machines. The method uses multiples of rotational speed (orders), rather than absolute frequency (Hz). The number of orders is input by the user. Order Tracking also minimizes the risk of smearing in spectrums.