EPRO PR6423/018-040 CON021 Eddy Current Sensor

Radial Shaft Vibration:

Dynamic displacement of the shaft perpendicular to its rotational axis.

Axial Shaft Displacement (Thrust Position):

Static and dynamic movement of the rotor along its axis relative to the casing.

Shaft Eccentricity:

Low-speed shaft runout, particularly important during turbine startup and shutdown to monitor thermally induced or gravity-induced shaft bow.

Rotational Speed (RPM):

Measurement of shaft rotational speed, typically using a gear or keyphasor target.

Keyphasor/Phase Reference:

Once-per-revolution signal for vibration phase measurement, balancing, and diagnostic analysis.

Q1: What industries and applications are EPRO sensors and monitoring systems primarily designed for?

A1: EPRO specializes in rotating machinery protection and condition monitoring. Their systems are predominantly used in heavy industries where critical turbomachinery operates, including power generation (steam, gas, and hydro turbines), oil & gas (compressors and pumps), petrochemical plants, and steel mills. Typical applications include non-contact eddy current vibration measurement, speed sensing, key phasing, and axial shaft position monitoring for bearings and seals.

Q2: What are the most common causes of signal drift or intermittent readings in an EPRO monitoring channel?

A2: Based on field failure analysis, the top causes are:

·Connector contamination or corrosion – particularly the M12x1 or coaxial connectors exposed to oil mist or moisture.

·Extension cable damage – from sharp bending, crushing, or repetitive flexing near the machine casing.

·Target material change – if a shaft surface is coated, corroded, or has different magnetic properties than the factory calibration target.

Q3: Are EPRO sensors affected by magnetic fields from adjacent machinery or by residual magnetism in the shaft itself?

A3: EPRO eddy current sensors are inherently immune to static or slowly changing magnetic fields from adjacent machinery, as their high-frequency operating principle does not interact with such fields. However, residual magnetism in the shaft itself requires attention. While a magnetized shaft does not directly affect the sensor output, it alters the shaft's magnetic properties, which influence eddy current formation and thus affect measurement sensitivity and linearity. EPRO calibrates its sensors against non-magnetized 42CrMo4 steel, so shaft magnetization can compromise calibration accuracy. Minor residual magnetism is generally acceptable for monitoring, but severe magnetization—caused by welding currents, lightning strikes, or improper use of magnetic tools—can introduce significant errors.