Manfred Weber
Metra Mess- und Frequenztechnik in Radebeul e.K.
PC Vibration Measurement System VibroMetra

Main vibration display for balancing run

Vibration measurement is performed in initial runs, test runs and verification runs. The measured vibration values are intermediate results for the calculation of the final unbalance.
In the vibration diplay you find the button for starting a measurement. If rotation speed reaches the specified range, vibration is measured and indicated. After measuring the specified number of revolutions VM-BAL stops vibration measurement.
Depending on the selected mode VM-BAL will switch to the next step or wait for user control. You may always return to the vibration display by selecting Vibration measurement in list of measuring runs.
Main vibration display for balancing run


1. Start/Stop
Starts and stops vibration measurement. VM-BAL will stop measurement automatically after reaching the entered number of revolutions. Hence a manual stop is usually not necessary.

Rotation speed monitoring

2. Rotation speed monitoring
Rotation speed is monitored before and during vibration measurement.
In the first measuring run there is no nominal speed. In this case VM-BAL only checks whether rotation speed is within the limits for a sufficiently long period.
By this means VM-BAL can find a nominal speed and starts vibration measurement. If the actual rotation speed differs from the nominal value VM-BAL will discard the measured vibration values, find a new nominal speed and restart the measurement.
In further measuring runs the nominal speed is fixed and vibration measurement is performed only at rotation speeds within the specified limits.

Measuring values

3. Measuring values
For both planes amount and phase angle are indicated with the selected unit.


4. Diagram
The vibration value is shown as a pointer. The angle is marked according to the settings. Fixed positions are indicated in the diagram.

Inspecting single measurements

5. Inspecting single measurements
This feature informs about deviation of the averaged single measurement.
High deviations can reduce the reliability of the result. This can happen when the unbalance becomes so low that there is almost no remaining vibration. On the other hand there can be fundamental problems, for example strong interference by external sources. The image shows a measurement of good quality.

Status bar

6. Status bar
The following properties of the measuring channel are shown: