Product Overview

The Epro PR6424/010-140 + CON021 16 mm Eddy Current Sensor is a non-contact displacement measurement solution designed for monitoring the condition and operating behavior of critical rotating machinery. It belongs to the EPRO PR6424 eddy current sensor family and is intended for applications where accurate shaft displacement and vibration measurements are important for equipment protection and predictive maintenance.

The PR6424 probe operates using the eddy current measurement principle. It detects changes in the distance between the sensor tip and a conductive target, such as a rotating steel shaft. As the shaft moves or vibrates, the distance changes, producing a corresponding electrical signal. This signal can be processed by a compatible converter and monitoring system to evaluate shaft movement and machine condition.

The PR6424/010-140 is a 16 mm probe configuration. When paired with the CON021 signal converter, it forms part of a measurement chain suitable for monitoring radial shaft vibration, axial displacement, shaft position, eccentricity, and speed-related conditions.

The system is relevant to critical machinery such as steam turbines, gas turbines, compressors, pumps, and industrial fans. These machines often operate continuously under changing mechanical and thermal conditions. Reliable displacement measurements help maintenance personnel identify abnormal shaft movement and investigate potential mechanical problems before they develop into serious equipment failures.

The sensor uses a non-contact measurement method, so it does not need to touch the rotating shaft during normal operation. This makes it suitable for continuous monitoring in machinery where direct mechanical contact would be impractical or undesirable.

Technical Specifications

Note: The specifications above describe the PR6424 sensor family and its measurement principle. Confirm the exact cable length, connector, converter configuration, and environmental limits for the supplied PR6424/010-140 assembly.

Function and Working Principle

The PR6424/010-140 measures the distance between its sensing tip and a conductive target without physical contact. Its operating principle is based on electromagnetic induction.

1. Eddy Current Measurement

The sensor contains a coil that generates an electromagnetic field when supplied with the required electrical signal. When a conductive metal target approaches the probe, eddy currents are induced in the target surface.

These currents influence the electromagnetic characteristics of the sensor coil. The resulting electrical change is related to the distance between the probe tip and the target.

By measuring this change, the system can determine variations in shaft position and movement.

2. Radial Shaft Vibration Measurement

Radial vibration describes movement of a rotating shaft perpendicular to its centerline. In a typical installation, two displacement probes may be positioned at different angular locations around the shaft to measure movement in two directions.

The resulting signals can help monitoring equipment identify changes in shaft vibration, imbalance, misalignment, looseness, or other mechanical conditions.

The PR6424 provides a non-contact measurement method suitable for continuous monitoring when correctly installed and calibrated.

3. Axial Displacement Measurement

Axial displacement refers to movement of a shaft along its rotational axis. Excessive axial movement may indicate changes in thrust-bearing condition, thermal expansion, or other mechanical problems.

A properly positioned eddy current probe can monitor the distance to an appropriate shaft target or thrust collar. The monitoring system can then evaluate the measured movement against configured operating limits.

4. Signal Conversion Through CON021

The CON021 is a signal converter designed for compatible EPRO eddy current probes, including the PR6424 series.

The probe and converter must be treated as a matched measurement chain. The converter processes the sensor signal and provides an output suitable for connection to compatible machinery-monitoring equipment.

Correct matching of the probe, cable, connector, and converter is essential. Using an incompatible converter or cable arrangement can cause inaccurate measurements or prevent the system from operating correctly.

5. Continuous Machinery Condition Monitoring

When connected to a suitable monitoring system, the sensor can provide continuous measurement information. Maintenance personnel can use the resulting data to identify changes in shaft movement and evaluate machine operating conditions.

Trend analysis is particularly useful because gradual changes may indicate developing mechanical problems that are not immediately visible during routine inspections.

Role in Industrial Machinery Protection Systems

The PR6424/010-140 + CON021 measurement chain can serve as part of a machinery protection and condition-monitoring installation.

Turbine Monitoring

Steam and gas turbines contain rotating shafts operating under demanding mechanical and thermal conditions. Shaft displacement and vibration measurements help engineers assess rotor behavior and bearing performance.

Eddy current probes are commonly installed near bearing housings or other designated measurement locations to monitor shaft movement continuously.

Compressor Monitoring

Industrial compressors are used in petrochemical facilities, natural gas processing, refrigeration systems, and other industrial processes.

Abnormal shaft vibration or axial movement may be associated with bearing deterioration, rotor imbalance, alignment problems, or changes in operating conditions. A properly configured PR6424 measurement chain can provide useful information for monitoring these conditions.

Pump Monitoring

Large industrial pumps may operate continuously in water treatment plants, power stations, chemical facilities, and manufacturing processes.

Shaft displacement measurements can support the evaluation of mechanical stability and help maintenance personnel investigate abnormal vibration or changes in bearing behavior.

Integration With Monitoring Equipment

The sensor and converter can be incorporated into a compatible machinery-monitoring architecture. The monitoring equipment receives the converted measurement signal and evaluates it according to the configured alarm and protection requirements.

The exact interface, signal scaling, and alarm logic depend on the receiving monitoring system and its configuration.

Industrial Applications

1. Steam Turbines

Steam turbines are used in power generation and industrial energy systems. Their rotating components operate under high mechanical and thermal loads.

The PR6424 can be used in suitable turbine monitoring installations to measure shaft vibration and displacement. These measurements help engineers assess rotor behavior and investigate potential changes in bearing or shaft conditions.

2. Gas Turbines

Gas turbines are used in power generation, mechanical drive systems, and industrial energy applications.

Continuous shaft monitoring is important because unexpected rotor movement can affect equipment reliability. Eddy current sensors provide non-contact measurements that can be incorporated into an appropriate turbine protection system.

3. Centrifugal Compressors

Centrifugal compressors are widely used in oil and gas processing, petrochemical production, and industrial gas handling.

Shaft vibration and axial displacement measurements can help identify changes in rotor behavior. Monitoring trends may support maintenance planning and reduce the likelihood of unexpected equipment shutdowns.

4. Industrial Pumps

Large pumps are essential in water treatment, chemical processing, power generation, and manufacturing facilities.

A displacement sensor can monitor shaft movement in suitable pump installations, helping maintenance teams assess mechanical operating conditions and investigate abnormal vibration.

5. Industrial Fans

Large fans and blowers are used in ventilation systems, furnaces, boilers, and process plants. Where continuous shaft monitoring is required, non-contact displacement sensors can provide information about rotating-shaft behavior.

Installation and System Integration

Correct installation is essential for obtaining reliable measurement results from the PR6424/010-140 and CON021 measurement chain.

1. Verify the Complete Measurement Chain

Before installation, confirm that the probe model, cable arrangement, connector, and CON021 converter are compatible.

The full model number should be checked against the existing equipment documentation. A replacement probe with the same 16 mm head diameter may still have different cable, connector, or measurement-chain characteristics.

2. Select the Correct Mounting Position

The probe should be mounted at the measurement location specified by the machinery design.

For radial vibration monitoring, the sensor is normally positioned near a suitable shaft surface. For axial displacement monitoring, it may be directed toward an appropriate axial target or thrust collar.

The mounting position must provide sufficient mechanical clearance and avoid interference with moving components.

3. Establish the Correct Air Gap

The distance between the probe tip and the target surface is an important installation parameter.

The PR6424 family specifies a nominal center air gap of approximately 2.7 mm. The final installation gap must be established according to the manufacturer’s calibration procedure and the requirements of the complete measurement chain.

An incorrect gap may reduce the available measurement range or cause the output to operate outside its intended linear region.

4. Check the Target Surface

Eddy current measurements depend on the electrical and magnetic characteristics of the target material.

The standard target specified for the PR6424 family is ferromagnetic steel, with 42CrMo4 identified as the standard material. Shaft material, surface condition, geometry, and target dimensions should be considered during installation and calibration.

5. Connect the Probe to CON021

Connect the sensor using the specified cable and connector arrangement. Avoid excessive cable bending, mechanical tension, and exposure to conditions beyond the cable’s environmental rating.

The converter should be installed in a suitable location with appropriate electrical protection and wiring access.

6. Calibrate and Verify the Signal

After installation, follow the manufacturer’s calibration and commissioning procedures. Confirm that the measured gap corresponds to the expected output and that the signal changes consistently with controlled target movement.

Check the complete measurement chain before connecting it to machinery protection logic. Alarm and trip thresholds must be established by qualified personnel according to the machinery design and applicable standards.

Compatible System Components

The PR6424/010-140 is intended to operate as part of a complete displacement measurement system. The following components may be relevant to an installation.

The table identifies typical system components. It does not mean that all components are included with the sensor assembly.

Alternative Models and Replacement Considerations

The PR6424 family includes different probe configurations. Replacement selection must consider the complete measurement-chain requirements rather than sensor diameter alone.

Before selecting an alternative, compare:

• Probe diameter and mechanical mounting dimensions.
• Cable length and cable protection.
• Connector type and pin arrangement.
• Compatible signal converter.
• Sensitivity and measurement range.
• Target material and shaft dimensions.
• Temperature and environmental requirements.
• Monitoring-system input characteristics.
• Calibration and commissioning requirements.

A replacement should be approved against the original measurement-chain documentation. Similar product names or physical dimensions do not guarantee electrical or mechanical interchangeability.

Key Advantages

Non-Contact Measurement

The PR6424 measures shaft movement without direct physical contact. This makes it suitable for continuous monitoring of rotating machinery.

16 mm Sensor Design

The 16 mm probe configuration is designed for applications requiring the PR6424 measurement range and mechanical mounting arrangement.

Displacement and Vibration Monitoring

The sensor can support radial shaft vibration and axial displacement measurements when installed in an appropriate measurement arrangement.

Stable Measurement Characteristics

The PR6424 family specifies a sensitivity of 4 V/mm and linearity of up to ±1.5%, supporting measurement applications that require consistent displacement signals.

Compatibility With CON021

The PR6424 can be used with the compatible CON021 signal converter as part of an EPRO eddy current measurement chain.

Application in Critical Rotating Machinery

The measurement principle is suitable for turbines, compressors, pumps, and fans where shaft movement is an important machinery-condition parameter.

Technical FAQs

1. What is the Epro PR6424/010-140 + CON021?

It is an EPRO 16 mm eddy current measurement configuration consisting of a PR6424 displacement probe and its compatible CON021 signal converter.

2. What does the PR6424 sensor measure?

It measures the distance between the probe tip and a conductive target. In rotating machinery applications, this measurement can be used to monitor radial shaft vibration, axial displacement, shaft position, and eccentricity.

3. What is the diameter of the sensor head?

The sensor head diameter is 16 mm.

4. What is the sensitivity of the PR6424 series?

The published typical sensitivity is 4 V/mm. The exact measurement-chain configuration and calibration should be checked before commissioning.

5. What is the measuring range?

The PR6424 family specifies a static range of ±2.0 mm and a dynamic range of 0 to 1,000 μm.

6. What is the function of the CON021?

The CON021 is an eddy current signal converter designed for compatible EPRO probes. It processes the probe signal and provides an output suitable for a compatible monitoring system.

7. Can the PR6424 be used for turbine monitoring?

Yes. The PR6424 family is designed for critical turbomachinery applications, including steam turbines, gas turbines, and hydro turbines, as well as compressors, pumps, and fans.

8. Does the probe need to touch the shaft?

No. It uses the eddy current principle to measure the distance to the conductive target without physical contact during normal operation.

9. Can another 16 mm probe replace the PR6424/010-140?

Not automatically. The probe version, cable, connector, converter, sensitivity, and measurement range must all be checked before replacement.

10. What should be checked before purchasing?

Confirm the full model number, probe condition, cable length, connector, compatible CON021 converter, and whether the quoted product includes the complete measurement chain. For replacement applications, compare the original equipment documentation with the supplied configuration.

Procurement and Maintenance Recommendations

When purchasing the Epro PR6424/010-140 + CON021, verify whether the supplier is offering the probe alone or a complete measurement assembly. The distinction is important because the PR6424 probe and CON021 converter are separate components with different functions.

Request clear photographs of the probe identification label, connector, cable, and converter. Confirm cable length, cable protection, connector type, and the condition of the sensing tip. For critical machinery, it is advisable to request available calibration or functional-test information.

During maintenance, inspect the probe mounting, cable routing, connector condition, and converter wiring. Mechanical damage, loose connections, cable deterioration, or an incorrect installation gap can affect the measurement signal.

If the sensor is replaced, verify the new probe against the original measurement-chain configuration. Recheck the air gap, calibration, signal scaling, and monitoring-system alarm settings before returning the machine to service.

Conclusion

The Epro PR6424/010-140 + CON021 16 mm Eddy Current Sensor is designed for non-contact displacement measurement in critical rotating machinery. Its measurement capabilities support shaft vibration, axial displacement, position, and eccentricity monitoring in applications such as turbines, compressors, pumps, and industrial fans.

With a typical sensitivity of 4 V/mm and a specified static measuring range of ±2.0 mm, the PR6424 family provides a measurement solution for machinery-condition monitoring systems. Correct probe-to-converter matching, installation gap adjustment, calibration, and signal verification are essential for reliable operation.

For maintenance and replacement projects, confirming the complete PR6424/010-140 and CON021 configuration helps ensure that the supplied equipment is suitable for the existing machinery monitoring system.