Using vibration measurements, we the determine the vibration behavior of machines and installations. On the basis of the pattern which is measured, we can make statements about the condition of the machine. DB Asset Services performs vibration measurements mainly to identify misalignment, foundation problems, bearing and gear damage.
Principle of vibration measurements
This technology has similarities with a doctor examining a patient: by using a stethoscope to listen to the heart, lungs, etc., the doctor can determine if the patient has certain diseases / disorders by listening to the sound.
For vibration measurements distinction is made between low-and high-frequency vibrations.
Extending life time
The use of vibration measurements makes it possible to identify problems at an early stage and makes it possible to take Proactive action. Thus, it is for example possible to correct misalignment in time, which will extend the life of the machine. It is also possible extend the maintenance intervals in a responsible way in case the measurements show that there are no problems.
Low-frequency vibrations
Low frequency vibrations are vibrations with a frequency till 1000Hz. In this range the machine vibrates as a whole, which can be also felt by hand. Although there is usually no damage (yet), there is an increased risk of damage. By analyzing the measurements and look into specific frequencies, the cause can be identified. This includes for example: misalignment, imbalance and resonance.
High frequency vibrations
High-frequency local vibrations (1000Hz to 20kHz) occur due to metallic contact between rotating parts. The machine makes noise, but no perceptible vibrations yet. This occurs, amongst others, when bearing failures occur. The surface of the lubricating film is locally broken, and creates metal-to-metal contact which in turn causes high-frequency pulses. In the same way lubrication problems may be detected in this manner.
Analysis
Analyzing of measuring results requires a lot of experience, because many 'environment vibrations' and innocent vibrations are also measured. The ‘damage frequencies’ must be separated from the normal frequencies. In addition, the level of damage has to be determined often blurred by various influences.
