Vibration Comparator Frequently Asked Questions

How should I determine the settings when installing it for the first time?

When setting comparison values for the first time;

Depending on what you are measuring, such as bearing damage, shaft runout, or imbalance, there are frequencies that you should pay attention to.

• Shaft runout, play, and imbalance cause abnormal vibrations at a frequency that matches the shaft rotation speed.
• In gears, abnormal vibrations occur at a frequency that matches "shaft rotation speed × number of teeth".
• Damage to the bearings causes abnormal vibrations at high frequencies of several kHz or higher, so set the high-pass filter to 1 kHz.
  (We also sell the VC-3100, a dedicated device for inspecting bearing damage.)

Set the appropriate bandpass frequency according to the frequency of interest.
The effective value or peak value for both normal and abnormal cases is measured to estimate the judgment level. If data for abnormal cases cannot be obtained, the normal value can be used as a reference, for example, by setting the level slightly higher than the maximum value or by +3σ (σ: standard deviation).

If an anomaly is detected, please review the data to determine if the comparison values are appropriate.
Additionally, if you have an FFT analyzer, you can use the measurement data to determine which frequency bands are prone to anomalies and set the bandpass filter more precisely.

The VC-2100 allows you to independently set two types of bandpass filters (frequency bandwidth limiting) and outputs a comparative result. The example in the figure below shows the settings with f1 to f2 for band A and f3 to f4 for band B.