Vibration and Runout Measurement

Vibration, at least in the industrial and measurement context, refers to the mechanical oscillations of machines, equipment, and structures. Vibration analysis is an important element of predictive maintenance, as it allows maintenance teams to identify changes in how different machinery operates, indicating wear or impending failure.

Sensors and data acquisition systems are commonly used for vibration measurement and detect different anomalies. These systems help monitor this mechanical phenomenon, increase the life of machinery, maintain product quality, and ensure employee safety.

Vibration is a periodic or cyclic (and thus time-based) displacement of an object around its center static position. If all bodies, when perfectly balanced, produce negligible rotation, any rotation outside the tolerable margins is considered negatively impactful on the longevity and proper operation of rotating machines and equipment.
Measuring vibration is complicated due to numerous factors that contribute to vibration, such as the object’s natural frequencies, the amplitude and frequencies of external elements, and the coupling mechanism between the vibrating energy source and the object of interest. It’s commonly observed in misalignments between motor and pump shafts in industrial settings.

There are many different vibration monitoring systems, each with its own operating principles. KEYENCE manufactures non-contact, high-precision instruments used for measuring many different physical properties (including vibration).

Vibration measurement can be carried out by using vibration monitoring equipment like the LK-G Series displacement sensor, which relies on laser triangulation to measure vibrations. The laser-emitting element fires a beam at the target surface. The light is reflected off the target and detected by the light-sensitive receiving elements.

The sensor detects the position and angle at which the light lands on the light-sensitive element and uses that information to derive the distance between the surface and the sensor. However, the vibration creates variations in the distance between the surface and the sensor, and this variation is evaluated and presented as an oscillation of the target surface.

Other sensor types, such as the SI Series or LS Series, can similarly determine these measurements—they detect the variability in distance or position between the measured surface and the sensor to evaluate target variation and present it as an oscillation or vibration measurement.

The benefits of vibration measurement sensors mostly depend on the context of vibration measurement and monitoring. Vibration measuring and monitoring devices play a critical role in measuring naturally occurring vibrations, such as geological monitoring, structural health monitoring, and environmental studies.

Monitoring geological vibrations is important, as they can provide early warning for natural disasters or provide insight into the structural integrity of bridges, buildings, and dams. This also applies to regulatory compliance and public safety.

In the context of manufacturing, vibration monitoring devices detect early signs of equipment malfunction or failure. This allows predictive maintenance to occur before a major breakdown occurs, resulting in reduced costs, reduced downtime, and the expanded life of machinery and operational equipment.

Additionally, many industries require vibration monitoring equipment and vibration control to protect worker health and safety and minimize environmental impact.

Vibration monitoring sensors, like laser displacement sensors, are important for applications where physical contact with the measured object could affect the measurement results. Here are a few key features of these vibration measurement sensors.

Runout is an inaccuracy associated with rotating mechanical systems, which occurs when the shaft doesn’t rotate exactly in line with the main axis. Interestingly enough, runout is dynamic and can’t be entirely removed. Just like vibration measurement, it can’t be eliminated entirely but can be minimized to acceptable levels.
Runout measurement, on the other hand, serves to assess the deviation of a rotating part from its main axis; all rotating systems suffer from runout, and these inaccuracies may compound or cancel out in a rotary system but never entirely dissipate.

KEYENCE is the world's leading provider of precision technologies for measuring, quality assurance, and quality control applications—including vibration monitoring. If you're looking to enhance the precision of your vibration monitoring systems, contact KEYENCE and inquire about integrating their equipment with your current manufacturing lineup.