Proximity sensors with an integrated driver suitable for measuring shaft vibration

Condition monitoring specialists Sensonics has introduced a new range of proximity sensors with an integrated driver suitable for measuring shaft vibration, position and speed on rotating plant.  Building on its Senturion proximity probe range, the new PRI Series offers a single probe assembly solution with direct processed outputs.

Proximity probe systems are usually made up of a calibrated probe, extension cable and driver. Utilising the eddy current principle, this combination forms a tuned circuit with the target material and variations in probe face to target distance are detected in this circuit by the separate driver. The PRI series provides this complete functionality in a single probe assembly mounted on the machine offering either a M12 connector interface for the 5mm range probe or an integral cable for the 2mm range option.

A typical application that the PRI range probe is suited to is the monitoring of large marine diesel engines where the use of separate drivers is not a preferred solution due to the high channel count and associated expense. Monitoring of piston BDC (bottom dead centre) position during engine operational hours is a critical measurement to determine wear in crank bearings and permits the owner to plan maintenance intervals well in advance, essential for marine operations. The probe temperature range is limited to 80⁰C due to the integrated electronics and is therefore also suitable for most pumps, fans and hydroelectric generator vibration monitoring applications. Removing the need for the separate driver and associated housing provides a significant cost saving with no compromises in measurement accuracy.

The PRI series offers processed outputs of shaft vibration and position through a 4-20 mA current loop and is suitable for OEM applications, connecting directly to the local machine PLC or a plant wide DCS. Customised outputs are also available on request for specific applications.

The probe also provides a raw buffered output of the measured signal that can be utilised through portable analysis equipment for a more detailed picture of the dynamic performance of the machine.