EPRO PR6423 and PR6424 Eddy Current Displacement Probes

The EPRO PR6423 and PR6424 are precision eddy current displacement sensors designed for non-contact measurement of static and dynamic positions of rotating shafts. They are part of the CONTREC series and are widely used in API 670-compliant machinery protection systems. The PR6423 features an 8 mm probe diameter with a linear measurement range of 2 mm, while the PR6424 has an 11 mm diameter with a 4 mm range, allowing selection based on application requirements. Both probes operate on the eddy current principle, generating a low-power RF field that interacts with the conductive target, producing an output voltage proportional to the gap. They offer excellent linearity, temperature stability, and long-term reliability in harsh industrial environments.

Key Features (Common to Both)

• Non-Contact Measurement: No mechanical wear, suitable for high-speed rotating shafts.

• High Linearity: ±1% of full scale over the measurement range.

• Temperature Stability: Low thermal drift ensures accurate measurements across varying operating conditions.

• Rugged Construction: Stainless steel housing, hermetically sealed tip, IP68 protection.

• Interchangeable: Designed for use with EPRO signal conditioners (CON021, MMS6000) for seamless system integration.

• API 670 Compliant: Meets the stringent requirements of API 670 for eddy current probes.

PR6423 Specifics (8 mm Probe)

• Probe Diameter: 8 mm

• Linear Range: 2 mm

• Sensitivity: 8 V/mm (nominal) with standard target (4140 steel)

• Thread: M8x1

PR6424 Specifics (11 mm Probe)

• Probe Diameter: 11 mm

• Linear Range: 4 mm

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

• Thread: M12x1

Technical Specifications (Both)

• Frequency Response: 0 to 10 kHz (limited by signal conditioner)

• Target Material: Ferromagnetic or non-ferromagnetic conductive materials (calibration required for non-standard materials)

• Cable Options: Integral cable with various lengths and connectors (customizable)

• Operating Temperature (Tip): -30°C to +120°C (extended versions available)

• Protection Class: IP68 (probe body)

• Certifications: CE, ATEX / IECEx optional for hazardous areas

Applications

These probes are used in critical rotating machinery such as steam turbines, gas turbines, centrifugal compressors, pumps, and fans. They measure radial shaft vibration, axial displacement (thrust position), shaft eccentricity, and keyphasor® events. The PR6423 (8mm) is typically used in smaller machines or where space is limited, while the PR6424 (11mm) is preferred for larger shafts requiring a longer measurement range.

Integration and Calibration

The sensors are connected to EPRO signal conditioners (e.g., CON021, MMS6312) that provide oscillator, demodulator, and power. The system is calibrated with the target material used in the machine (typically 4140 steel). Extension cables (PR6426 series) are available for remote mounting. Probes are supplied with a calibration certificate traceable to international standards.

Reliability and Environmental Compliance

Built to withstand harsh industrial conditions, these probes meet rigorous standards for vibration, shock, and temperature. Their IP68 rating ensures protection against dust and temporary immersion. They are CE marked and available with hazardous area certifications for use in explosive atmospheres.

With their proven accuracy and durability, the EPRO PR6423 and PR6424 eddy current probes are trusted components in machinery protection systems worldwide.