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

Rotation speed

Balancing is performed at constant rotation speed. VM-BAL uses the rotation speed signal from the photoelectric reflex switch VM-PS which is connected to the digital input of the M302 / M312. Alternatively signals from rotor-specific sensors can be measured like, for  example, the z signal of a rotary encoder.
Rotation speed

Signal source

1. Signal source
Default setting is the digital input of the USB device.

Maximum deviation

2. Maximum deviation
Constant speed is crucial for successful balancing. VM-BAL monitors the stability of rotation speed to ensure that balancing is performed within specified limits.
The allowable deviation will depend on the type of drive and load variance. For a controlled drive with low load the preset of 2 % can be higher than the actual variations. The situation may be different for a combustion engine controlled by a foot throttle.

Cycles for measurement run

3. Cycles for measurement run
Here you enter the number of revolutions used for vibration measurement. The higher the number of revolutions the better VM-BAL can distinguish unbalance from vibration of other sources.

Start speed

4. Start speed
VM-BAL covers a very wide range of rotation frequencies from 6 to 100,000 rpm and higher.
For monitoring the stability at low speeds VM-BAL needs to measure over a longer period which may take some time. Operation can be sped up by entering a minimum rotation speed. The entered value should be at least the nominal speed less the expected tolerances.