Vibration measurement is essential for the maintenance and optimization of rotating machinery. Accurate monitoring prevents costly failures, improves efficiency, and extends the lifespan of industrial assets. Proximity probes and seismic sensors are among the most commonly used tools, each with specific applications and advantages.
As proximity probes detect relative shaft vibration and displacement without physical contact, preserving components and offering high accuracy. seismic sensors, such as accelerometers and speed sensors, capture absolute vibrations from the machine's casing, covering a wide frequency range.
Main features of proximity probes
These non-contact sensors measure shaft vibration in machines with fluid film bearings. They work well in high temperatures or oily environments and allow for the evaluation of both dynamic vibrations and static position.
Furthermore, Metrix offers field-configurable digital systems that increase accuracy. While calibration is essential and the measurement surface must be conductive, trend analysis over time ensures excellent diagnostic value.
How Seismic Sensors Work
Seismic sensors measure absolute vibrations of the housing and are ideal for rolling element bearing machines. Accelerometers capture frequencies above 2.000 Hz, while speed sensors cover the range from 10 Hz to 2.000 Hz. They are versatile, portable, and suitable for quick inspections.
Despite limitations at low frequencies and the need for firm mounting, their versatility makes them indispensable in vibration analysis.
Comparing technologies
Proximity probes measure relative vibration, while seismic sensors record absolute vibration. In some cases, combining the two technologies provides a complete picture of shaft motion, especially when the casing is light relative to the rotor.
The choice depends on factors such as machine type, bearing, frequency range of interest and available budget.
Which sensor to choose
Turbines, compressors, and low-speed machines tend to benefit from proximity probes, particularly for tracking shaft centerline position. Seismic sensors are more suitable for detecting bearing or gear failures.
In many cases, combining the two technologies is the best strategy for a more complete diagnosis.
To find out which solution is ideal for your case, talk to Metrix expertsOur team can recommend the most efficient configuration to ensure accurate and reliable vibration monitoring data.
Content adapted from an article published in metrixvibration
