Product Overview

The Epro PR6424/010-130+CON021 16 mm Eddy Current Sensor is a non-contact displacement measurement configuration designed for monitoring the condition and operating behavior of rotating industrial machinery. It combines a PR6424 series eddy current probe with a CON021 signal converter, providing a measurement arrangement for applications that require continuous monitoring of shaft displacement, vibration, and position.

Manufactured within the Epro machinery monitoring product family, the PR6424 sensor is designed for demanding rotating equipment such as steam turbines, gas turbines, compressors, pumps, and industrial fans. These machines often operate under high mechanical loads and continuous operating conditions. Monitoring shaft movement and vibration can help maintenance teams identify abnormal operating behavior before it develops into a more serious equipment problem.

Unlike contact-based measurement devices, an eddy current sensor measures the distance between its probe tip and a conductive target without requiring physical contact. This makes it suitable for monitoring rotating shafts where mechanical contact would introduce wear or interfere with normal operation.

The PR6424 series uses a 16 mm sensor head and is designed for displacement measurement on suitable ferromagnetic steel targets. Its typical measurement characteristics include a sensitivity of 4 V/mm, a static measuring range of ±2.0 mm, and a dynamic measurement range of 0 to 1,000 μm. The CON021 signal converter conditions the probe signal for use with compatible machinery monitoring equipment.

The complete model designation, PR6424/010-130+CON021, should be checked when ordering a replacement. Probe cable configuration, connector arrangement, converter version, measuring range, and system calibration all affect compatibility.

Technical Specifications

Note: The values above describe the PR6424 sensor family and the supplied product configuration. Confirm the exact probe suffix, cable arrangement, converter variant, and calibration range against the unit’s nameplate and documentation before installation.

Function and Working Principle

The PR6424/010-130+CON021 operates through the eddy current measurement principle. The probe generates an electromagnetic field near a conductive target. Changes in the distance between the probe and target affect the electrical characteristics of the probe circuit. The resulting signal is processed by the compatible converter to produce a measurement signal representing the target’s relative position.

1. Non-Contact Displacement Measurement

The sensor measures the distance between its probe tip and a conductive machine surface without touching the target.

When installed near a rotating shaft, the probe can detect changes in the gap as the shaft moves. These changes may be associated with shaft vibration, displacement, or changes in mechanical position.

Non-contact measurement is particularly useful in rotating machinery because it avoids mechanical wear between the sensor and the shaft.

2. Eddy Current Signal Generation

The probe generates an alternating electromagnetic field. When a conductive target enters this field, eddy currents are induced in the target surface.

The strength and characteristics of these currents vary with the distance between the probe and the target. The sensor system uses this relationship to determine displacement.

For reliable measurement, the target material and surface characteristics must be compatible with the probe’s calibration. The PR6424 system is designed for suitable ferromagnetic steel targets, with 42CrMo4 commonly used as a reference material.

3. Signal Conversion Through CON021

The CON021 is an eddy current signal converter designed for compatible PR6424 probes. It processes the probe signal and provides a conditioned output for connection to suitable machinery monitoring equipment.

The converter’s configuration determines the supported measurement range and signal characteristics. Different CON021 ordering variants are available for different probe series and measuring ranges, so the exact converter designation must be checked.

4. Shaft Vibration and Position Monitoring

When mounted near a rotating shaft, the probe can measure changes in shaft position relative to the sensor mounting point.

These measurements can support:

• Radial shaft vibration monitoring.
• Axial displacement monitoring.
• Shaft position measurement.
• Shaft eccentricity monitoring.
• Rotating machinery condition monitoring.
• Speed or key-related measurement in suitable configurations.

The sensor measures relative movement between the target and the probe. Correct interpretation requires consideration of the machine structure, mounting stability, shaft material, and monitoring-system configuration.

Role in Industrial Machinery Monitoring Systems

The PR6424/010-130+CON021 is intended to function as part of a wider machinery monitoring and protection system. It does not operate as a standalone PLC or controller. Instead, it provides measurement information to compatible monitoring equipment.

1. Turbine Monitoring

Steam and gas turbines contain high-speed rotating assemblies that require continuous monitoring. Shaft displacement and vibration measurements can help operators evaluate rotor behavior and identify changes in operating conditions.

The PR6424 probe can be installed at suitable measurement locations to monitor relative shaft movement. Multiple sensors may be used to obtain a more complete picture of rotor behavior.

2. Compressor Condition Monitoring

Industrial compressors operate under changing loads and process conditions. Mechanical imbalance, misalignment, bearing problems, and other abnormal conditions can influence shaft movement.

A properly installed eddy current measurement system can provide continuous displacement data for machinery monitoring and maintenance analysis.

3. Pump Monitoring

Large industrial pumps may experience vibration and shaft movement due to hydraulic conditions, mechanical wear, or installation problems.

The PR6424 sensor can be used in suitable pump monitoring arrangements to measure shaft displacement and support condition-based maintenance.

4. Integration with Machinery Protection Equipment

The CON021 converter provides a conditioned signal for compatible monitoring equipment. Depending on the system architecture, the measurement may be used by machinery protection monitors, diagnostic systems, or plant control platforms.

Engineers must confirm electrical output characteristics, input compatibility, scaling, and alarm configuration before connecting the measurement chain to downstream equipment.

Industrial Applications

The PR6424/010-130+CON021 is intended for industrial applications where reliable monitoring of rotating machinery is important.

1. Steam Turbines

Steam turbines operate at high rotational speeds and require monitoring of shaft vibration and displacement. Changes in rotor movement may indicate mechanical imbalance, alignment problems, or other developing equipment issues.

Eddy current probes provide non-contact measurement of shaft movement and can form part of a continuous turbine monitoring system.

2. Gas Turbines

Gas turbines are used in power generation and industrial drive applications. Their rotating assemblies operate under demanding thermal and mechanical conditions.

A suitable PR6424 measurement installation can help monitor relative shaft movement and provide information for machinery condition assessment.

3. Industrial Compressors

Centrifugal and other large rotating compressors require reliable monitoring to maintain stable operation. Shaft displacement measurements can help maintenance personnel evaluate rotor behavior and investigate abnormal vibration trends.

The sensor’s installation and calibration must be matched to the compressor shaft material and measurement geometry.

4. Industrial Pumps

Large pumps used in power plants, chemical facilities, and process industries may require continuous monitoring of rotating components.

The PR6424 can be applied where non-contact shaft displacement measurement is required and the installation conditions match the probe’s specifications.

5. Industrial Fans

Large industrial fans and blower assemblies may experience imbalance, shaft movement, and vibration during operation.

A suitable eddy current sensor arrangement can provide measurement information for condition monitoring and maintenance planning.

6. Power Generation Equipment

Power generation facilities depend on the availability of turbines, compressors, pumps, and other rotating equipment. Continuous machinery monitoring helps maintenance teams identify changes in equipment behavior and plan inspections.

The PR6424 and CON021 combination can be incorporated into compatible monitoring arrangements for selected rotating machinery.

Installation and System Integration

Correct installation is essential for obtaining stable and repeatable measurements from an eddy current sensor system.

1. Verify Probe and Converter Compatibility

Before installation, confirm that the PR6424/010-130 probe is compatible with the specified CON021 converter.

Check the complete model designation, probe cable configuration, connector type, converter variant, measuring range, and calibration information. A converter designed for a different probe configuration may produce inaccurate measurements or fail to operate correctly.

2. Select an Appropriate Mounting Position

The probe should be mounted at a location that provides a suitable measurement surface and stable mechanical support.

For shaft displacement monitoring, the mounting arrangement must maintain the specified probe-to-target geometry throughout normal machine operation.

Avoid mounting locations where vibration of the sensor bracket could be mistaken for actual shaft movement.

3. Set the Initial Air Gap

The initial gap between the probe tip and the target is an important installation parameter.

The PR6424 family specifies a nominal center air gap of approximately 2.7 mm for its standard configuration. The exact installation gap should be established according to the probe and converter documentation.

An incorrect initial gap may reduce the usable measurement range or cause the output to operate outside its calibrated linear region.

4. Check Target Material

Eddy current measurement depends on the electrical properties of the target material.

The PR6424 is designed for suitable ferromagnetic steel targets, with 42CrMo4 used as a standard reference material in its specifications.

If the shaft material or surface treatment differs from the reference target, verify the calibration requirements before relying on the measurement.

5. Route and Protect the Sensor Cable

The probe cable should be routed away from high-power conductors and potential sources of electromagnetic interference where required.

Avoid excessive bending, crushing, or pulling force. Maintain the minimum bending radius specified by the manufacturer and protect cable connections from moisture, contamination, and mechanical damage.

6. Connect the CON021 Converter

Install the CON021 according to its mounting and wiring instructions. Confirm the power supply, probe connection, output wiring, and downstream monitoring input requirements.

The converter should be configured for the correct PR6424 probe and measuring range. Do not assume that every CON021 version uses the same range or output configuration.

7. Calibrate and Verify Measurement Signals

After installation, verify the initial gap and confirm that the output changes consistently as the target position changes.

Check the zero reference, measurement direction, signal scaling, and alarm settings. Where possible, compare the output with an independent measurement method during commissioning.

Record the final configuration so that future maintenance personnel can identify the correct probe, converter, and calibration settings.

Compatible System Components

The PR6424/010-130+CON021 is normally used as part of a machinery monitoring measurement chain.

These components are examples of a typical monitoring arrangement. They are not necessarily included with the supplied sensor and converter assembly.

Alternative Models and Replacement Considerations

The PR6424 belongs to the Epro 16 mm eddy current sensor family. Related models may have similar measurement principles but different probe configurations, cable lengths, measurement ranges, or operating conditions.

When selecting a replacement, compare the following:

• Complete probe model and suffix.
• Sensor head diameter and mounting thread.
• Probe length and cable arrangement.
• Connector type and cable termination.
• Compatible converter model.
• Measurement range and sensitivity.
• Target material and shaft diameter.
• Operating temperature requirements.
• Output characteristics and monitoring-system input.
• Calibration and installation requirements.

A probe with the same 16 mm head diameter is not necessarily a direct replacement. The complete measurement chain must be checked to ensure that the probe and converter operate together correctly.

Key Advantages

Non-Contact Measurement

The eddy current principle allows shaft displacement measurement without physical contact, avoiding mechanical wear between the probe and the rotating target.

Suitable for Critical Rotating Machinery

The PR6424 series is designed for machinery such as turbines, compressors, pumps, and fans, where continuous shaft monitoring can support equipment reliability.

High Measurement Sensitivity

The typical sensitivity of 4 V/mm supports measurement of relatively small changes in target position.

Static and Dynamic Measurement

The PR6424 family supports both static displacement and dynamic shaft movement measurement within its specified operating range.

Compatible Signal Conversion

The CON021 converter provides signal conditioning for compatible PR6424 probe configurations and downstream monitoring equipment.

Industrial Construction

The stainless-steel probe sleeve and PTFE cable are designed for industrial measurement environments within the specified operating limits.

Support for Condition-Based Maintenance

Continuous displacement and vibration measurements can help maintenance teams identify abnormal trends and plan inspections according to equipment condition.

Technical FAQs

1. What is the Epro PR6424/010-130+CON021?

It is an eddy current measurement configuration consisting of a PR6424 16 mm probe and a compatible CON021 signal converter. It is designed for non-contact monitoring of shaft displacement and related rotating machinery parameters.

2. What is the sensor head diameter?

The sensor head diameter is 16 mm, as specified for the PR6424 model family.

3. What is the typical sensitivity of the PR6424 sensor?

The typical sensitivity is 4 V/mm, with a specified linearity error of up to ±1.5% for the applicable standard configuration.

4. What is the measurement range?

The PR6424 family has a static measuring range of ±2.0 mm and a dynamic measuring range of 0 to 1,000 μm. The actual system range must be confirmed against the specific probe and CON021 converter variant.

5. What is the function of the CON021 converter?

The CON021 processes the signal from a compatible eddy current probe and provides a conditioned output for connection to suitable machinery monitoring equipment.

6. Can this sensor measure shaft vibration?

Yes. When correctly installed and connected to compatible monitoring equipment, the PR6424 can measure dynamic shaft displacement associated with vibration.

7. Which materials can the sensor measure?

The PR6424 is designed for suitable conductive ferromagnetic targets. Its standard reference target material is 42CrMo4 steel. Other target materials may require different calibration considerations.

8. What equipment can use this sensor?

Typical applications include steam turbines, gas turbines, compressors, pumps, and industrial fans. The sensor is suitable where non-contact shaft displacement or position monitoring is required.

9. Can the PR6424 probe be connected to any CON021 converter?

No. The exact converter variant and measurement range must match the probe configuration. Check the complete converter ordering designation and the manufacturer’s compatibility information before installation.

10. What should be checked before purchasing a replacement?

Verify the full PR6424 model number, 16 mm head diameter, probe length, cable and connector configuration, CON021 variant, measurement range, and physical condition. For critical machinery, confirm calibration and functional testing information.

Procurement and Maintenance Recommendations

When purchasing the Epro PR6424/010-130+CON021, confirm whether the product is supplied as a complete probe-and-converter assembly or as separate components. The product designation includes both the PR6424 probe and the CON021 converter, but the actual package contents should always be confirmed with the supplier.

Check the probe label and connector arrangement carefully. Cable length, cable protection, mounting dimensions, and converter version can affect compatibility with the existing machinery monitoring system.

For used or surplus equipment, request clear photographs of the probe body, cable, connectors, and converter label. Check for damaged insulation, bent connectors, corrosion, or mechanical damage to the sensor head. Where possible, request evidence of functional testing and calibration.

During maintenance, inspect the mounting bracket and cable routing. Ensure that the probe remains securely positioned and that the initial air gap has not changed. Unexpected changes in the measurement signal should be investigated alongside the machine’s operating conditions and the condition of the sensor installation.

Keep records of the probe model, converter model, calibration range, initial gap, and monitoring-system settings. These details can simplify future replacement and reduce the risk of installing an incompatible measurement component.

Conclusion

The Epro PR6424/010-130+CON021 16 mm Eddy Current Sensor is designed for non-contact displacement and vibration monitoring in critical rotating machinery. Combining a PR6424 probe with a compatible CON021 signal converter, it provides a measurement solution for applications involving turbines, compressors, pumps, and industrial fans.

Its typical 4 V/mm sensitivity, ±2.0 mm static measuring range, and 0–1,000 μm dynamic measuring range support shaft position and vibration monitoring within the specified operating conditions. Correct probe selection, converter compatibility, target material, installation gap, and calibration are essential for reliable measurement performance.

For industrial maintenance and replacement projects, verifying the complete model designation and measurement-chain configuration helps ensure that the replacement sensor can operate correctly with the existing machinery monitoring system.