EPRO PR6424/014-040 11mm Eddy Current Probe

The EPRO PR6424/014-040 is a high-performance eddy current sensor from the CONTREC series, featuring an 11mm probe diameter that provides an extended linear measurement range, typically up to 4 mm. This makes it particularly well-suited for monitoring applications on larger rotating machinery where greater measurement spans are required, such as axial thrust position, differential expansion, and vibration on heavy-duty steam turbines, gas turbines, generators, and large compressors. Like all PR642x probes, it operates on the eddy current principle for reliable, non-contact measurement and is a key component in EPRO's MMS 3000 and MMS 6000 machinery protection systems.

Key Features

• 11mm Probe Diameter: The larger diameter provides an extended linear measurement range (up to 4mm) compared to the 8mm PR6423, making it ideal for applications with larger dynamic movements.

• Extended Measurement Range: The 4mm linear range is particularly beneficial for measuring axial shaft displacement (thrust) and differential expansion, where movements can be larger than typical vibration amplitudes.

• High Sensitivity and Linearity: Provides precise, linear output over its entire measurement range, ensuring accurate representation of shaft position and movement. When used with a CON021 converter, linearity error is typically ≤1.5%.

• Rugged and Durable: Constructed with a stainless steel, hermetically sealed tip for exceptional resistance to harsh environmental conditions, including oil, moisture, and high temperatures.

• API 670 Compliance: Designed and manufactured to meet the rigorous standards of API 670 for machinery protection systems, ensuring high reliability and performance.

• Hazardous Area Certification: Available with ATEX and IECEx certifications (e.g., Eex ib II C T6/T4), allowing for safe installation in potentially explosive atmospheres common in the petrochemical industry.

Technical Specifications

• Probe Diameter: 11 mm

• Measurement Principle: Eddy current

• Linear Measurement Range: Up to 4 mm (0…±2.0…±3.0…±4.0 mm, depending on configuration) 

• Sensitivity: 4 V/mm (nominal with standard target material and converter)

• Thread Size: Typically M12x1 metric thread 

• Operating Temperature (Tip): -40°C to +85°C 

• Protection Class: IP65 or higher (probe body)

• Connector/Cable: The /014-040 suffix denotes a specific integral cable length and connector type (e.g., 4.0 meters) 

• Certifications: CE, ATEX / IECEx (for hazardous area variants) 

Applications

The PR6424/014-040 is ideally suited for critical measurements on large rotating machinery. Its extended range is essential for accurate axial position monitoring to prevent thrust bearing failure. It is also used for radial vibration monitoring on large-diameter shafts, differential expansion measurements between the rotor and casing, and eccentricity monitoring. Common applications include main steam turbines in power plants, large gas turbines in compressor stations, and heavy-duty centrifugal compressors in refineries.

Integration and Calibration

This probe is designed to operate with EPRO signal converters, most commonly the CON021 series. The converter provides the necessary excitation and converts the probe's impedance change into a voltage signal proportional to the measured displacement. The system is factory-calibrated for a specific target material (typically 4140 steel). The detailed model number, PR6424/014-040, specifies the exact probe configuration, including cable length, connector type, and any special certifications, ensuring the correct unit is used for the application.

Reliability and Environmental Compliance

Engineered for the most demanding industrial environments, the PR6424/014-040 offers exceptional reliability. Its hermetically sealed tip and robust housing protect against the ingress of oil, water, and chemicals. It is designed to withstand high levels of vibration and shock. The availability of ATEX/IECEx certified versions allows its use in safety-critical and hazardous areas, making it a versatile and trusted choice for comprehensive machinery protection in the oil, gas, and power industries.

The EPRO PR6424/014-040 eddy current probe provides the extended range and ruggedness required for protecting the largest and most critical rotating assets in the world.