Vibration analysis
EVAM®, the Evaluated Vibration Analysis Method, combines a number of established vibration analysis techniques with a machine specific statistical evaluation to supply easy to understand machine condition data.
The method has been developed to allow large scale, cost-efficient condition monitoring of industrial machinery:
- fast menu-guided set-up of measuring points
- easy data collection with hand-held data loggers or on-line equipment
- automatic condition evaluation
EVAM® works in three stages:
1. Vibration time record analysis
EVAM® fills the gap between broadband vibration severity measurements (the ISO recommended method) and the traditional type of spectrum analysis requiring a high level of operator training. Used at the most basic level, EVAM® supplies much more data than the ISO method without demanding more skill and time.
The automatic data processing returns up to 9 parameters for rotational forces, shock forces, and friction, providing a detailed picture of the vibration forces active on the machine.
2. Vibration spectrum analysis
Spectrum analysis is an integrated part of the software, allowing direct monitoring of a large number of specific mechanical faults.
EVAM® uses FFT to calculate one or several spectra per measuring assignment. For each measuring assignment, the user can select specific machine faults (unbalance, misalignment, motor and gear box faults, bearing damage, etc.) from a pre-programmed list of fault symptoms. This relieves the time-consuming task of searching the spectra for relevant condition information. Fault symptoms are automatically highlighted in the spectrum, and an individual parameter value is returned for each of them. This allows trending on specific machine faults, or a direct evaluation made by the software.
3. Machine specific condition evaluation
Using a set of vibration readings obtained during normal machine operation as base line data, all monitored parameters are compared with their mean values and standard deviation and displayed as condition values against a green - yellow - red scale. Without having to study any details, the user is provided instantly with a detailed status report covering all his selected condition and machine fault parameters. EVAM® is used in handheld data loggers, along with SPM bearing monitoring, ISO vibration severity monitoring, and other measuring and recording functions. SPM also supplies an online unit for frequency ranges up to 20000 Hz.