Product Overview

The Epro PR6424/010-030 16 mm Eddy Current Sensor is a non-contact displacement and vibration measurement sensor designed for monitoring rotating machinery in industrial environments. It belongs to the PR6424 sensor family, which is used in machinery protection and condition-monitoring applications involving steam turbines, gas turbines, compressors, pumps, fans, and other large rotating equipment.

Manufactured under the EPRO product line associated with Emerson, the PR6424 series uses eddy current measurement technology to detect changes in the distance between the sensor tip and a conductive metal target. This allows the sensor to monitor shaft movement without direct mechanical contact.

In rotating machinery, shaft displacement and vibration are important indicators of equipment condition. Excessive vibration, changes in shaft position, and abnormal mechanical movement may indicate bearing wear, rotor imbalance, misalignment, or other developing mechanical problems. Continuous monitoring helps maintenance teams identify unusual operating conditions and investigate potential faults before they lead to major equipment damage.

The PR6424/010-030 is identified as part of the 16 mm eddy current sensor family. The supplied product information specifies a 16 mm sensor head diameter and a weight of approximately 0.2 kg. The exact mechanical arrangement, cable configuration, and connector details should be confirmed against the complete model designation and the physical product.

For reliable measurement, the sensor must be used with a compatible signal converter or monitoring system. The complete measurement chain typically includes the probe, an extension or connecting cable where required, and a signal-conditioning unit.

Technical Specifications

Note: The performance figures above describe the PR6424 16 mm sensor family. Confirm the exact suffix-specific cable, connector, mounting, and converter compatibility before installation.

Function and Working Principle

The PR6424/010-030 operates using the eddy current principle. It generates a high-frequency electromagnetic field near the sensor tip and detects changes in that field when a conductive target moves relative to the probe.

1. Non-Contact Displacement Measurement

The sensor is installed near a conductive shaft surface without making physical contact with the rotating component.

When the distance between the sensor and the shaft changes, the electromagnetic field and the electrical characteristics of the probe change accordingly. A compatible signal converter processes this change into a measurable output.

This measurement method is particularly useful for rotating machinery because it avoids the mechanical wear associated with contact-based measurement devices.

2. Eddy Current Detection

The sensor produces an electromagnetic field at its sensing tip. When a conductive metal target enters this field, eddy currents are induced in the target surface.

Changes in the distance between the probe and the target affect the eddy currents and the impedance of the sensor coil. The resulting electrical variation is used to determine the relative position of the target.

A compatible converter conditions the probe signal and generates an output suitable for machinery monitoring equipment.

3. Shaft Vibration Monitoring

During normal operation, a rotating shaft may move slightly as a result of mechanical vibration. The PR6424 sensor detects these changes in the distance between the probe and the shaft surface.

The resulting measurement can be used to evaluate shaft vibration, identify abnormal movement, and monitor changes in machinery operating conditions.

Dynamic measurement is important for identifying vibration patterns that may be associated with imbalance, misalignment, bearing problems, or rotor-related mechanical issues.

4. Shaft Position and Axial Displacement

The sensor can also be used to monitor shaft position and displacement.

In suitable installations, it can measure radial or axial movement depending on the probe arrangement and monitoring-system configuration. Axial position monitoring is particularly important in turbine applications where changes in rotor position may affect clearances and mechanical operating conditions.

5. Signal Conditioning

The sensor probe is part of a measurement system rather than a standalone industrial voltage transmitter. Its electrical signal must be processed by a compatible converter.

The converter establishes the required measurement characteristics and provides an output that can be interpreted by a machinery protection or condition-monitoring system.

Correct probe, cable, and converter matching is essential for accurate measurements.

Role in Industrial Machinery Monitoring Systems

The PR6424/010-030 can serve as a sensing element within a wider machinery protection and condition-monitoring installation.

Turbine Protection Systems

Steam and gas turbines operate at high rotational speeds and under demanding mechanical conditions. Shaft vibration and displacement measurements are important for evaluating rotor behavior and identifying abnormal operating conditions.

The PR6424 series is designed for critical turbomachinery monitoring applications. When installed with suitable converters and monitoring equipment, it can contribute to continuous shaft-condition measurement.

Compressor Monitoring

Industrial compressors are used in petrochemical facilities, refineries, gas processing plants, and manufacturing systems. Their rotating components require reliable monitoring to support safe and stable operation.

Eddy current sensors can measure shaft movement without physical contact, providing information for vibration analysis and machinery condition assessment.

Pump Monitoring

Large industrial pumps may operate continuously under changing flow and pressure conditions. Changes in shaft vibration or position can provide useful information about mechanical condition.

A properly installed PR6424 measurement system can support monitoring of pump shafts and help maintenance teams investigate abnormal vibration patterns.

PLC and DCS Integration

The sensor itself should not be treated as a conventional PLC input device that can be connected directly without signal conditioning.

A compatible converter or machinery monitoring module processes the probe signal first. The resulting measurement can then be made available to a PLC, DCS, or plant monitoring system through the appropriate interface.

The actual integration method depends on the selected converter, monitoring rack, and system architecture.

Industrial Applications

1. Steam Turbines

Steam turbines are commonly used in power generation and industrial energy systems. Shaft vibration and displacement monitoring help operators evaluate rotor movement and identify changes in mechanical condition.

The PR6424 series is designed for this type of critical rotating machinery application.

2. Gas Turbines

Gas turbines operate under high-speed and high-temperature conditions. Monitoring shaft movement and vibration is an important part of machinery protection.

A non-contact eddy current sensor can provide continuous measurement of shaft displacement when installed with compatible monitoring equipment.

3. Hydro Turbines

Hydroelectric generating equipment includes large rotating assemblies that require ongoing mechanical condition monitoring.

Shaft displacement measurements can help identify changes in rotor behavior and support maintenance planning.

4. Industrial Compressors

Compressors are widely used in gas transmission, chemical processing, and industrial production. Shaft vibration monitoring helps identify mechanical changes that may affect operating reliability.

The PR6424 series can be used in suitable compressor monitoring arrangements.

5. Industrial Pumps

Large pumps in power plants, water treatment facilities, and process industries may require continuous shaft monitoring.

The sensor can measure relative shaft movement without contact, supporting the evaluation of vibration and displacement.

6. Industrial Fans

Large fans and ventilation systems may experience vibration caused by imbalance, mechanical looseness, or alignment problems.

When correctly installed, an eddy current measurement system can provide useful shaft movement information for condition-monitoring applications.

Installation and System Integration

Proper installation is essential for obtaining stable and accurate measurements from an eddy current sensor.

1. Confirm the Exact Sensor Configuration

Before installation, verify the complete model number PR6424/010-030 and compare it with the existing sensor specification.

Check the probe diameter, mounting thread, cable arrangement, connector type, cable length, and compatible converter. The suffix is important because different PR6424 configurations may have different mechanical and electrical arrangements.

Do not assume that every PR6424 sensor can be connected to the same converter without checking compatibility.

2. Prepare the Mounting Location

The sensor should be mounted securely near the shaft surface. The mounting arrangement must maintain a stable measurement gap while preventing unwanted movement caused by vibration or mechanical looseness.

The installation should also provide sufficient clearance around the probe and cable.

Avoid positioning the sensor where it may be exposed to mechanical impact, excessive contamination, or conditions outside its specified operating limits.

3. Set the Initial Air Gap

The PR6424 family has a nominal center air gap of approximately 2.7 mm.

The actual installation gap must be established according to the manufacturer’s instructions and the selected converter configuration. Correct gap adjustment is important because an incorrect initial position can reduce the usable measurement range or cause an inaccurate output.

4. Connect the Compatible Converter

Connect the probe to the correct signal converter using the specified cable and connector arrangement.

The converter must match the sensor configuration. Incorrect combinations may result in unstable readings, incorrect sensitivity, or an unusable measurement signal.

Check connector condition, cable continuity, shielding, and grounding before commissioning.

5. Configure the Monitoring System

After installation, configure the monitoring equipment according to the application.

Typical configuration work includes:

• Selecting the correct probe and converter combination.
• Setting the measurement range.
• Establishing the correct initial gap.
• Configuring vibration and position channels.
• Setting alarm and trip thresholds according to the machinery protection design.
• Verifying signal polarity and scaling.
• Checking the displayed measurement against the actual operating condition.

Alarm and trip limits should be established by qualified machinery engineers using the equipment design and applicable protection requirements.

6. Perform Functional Testing

After installation, verify that the sensor produces a stable measurement under the expected operating conditions.

Check the signal at the converter or monitoring module, confirm the displayed gap or displacement value, and inspect the signal for unexpected fluctuations.

Document the installed probe position, cable arrangement, converter model, and monitoring parameters for future maintenance.

Compatible System Components

The PR6424/010-030 should be considered as part of a complete eddy current measurement system.

A complete monitoring installation may require additional components that are not included with the sensor itself.

Alternative Models and Replacement Considerations

The PR6424 series includes different probe configurations. Replacement selection should be based on the complete model designation and system requirements rather than the sensor family name alone.

Before selecting a replacement, compare:

• Complete probe model number.
• Sensor head diameter.
• Mounting thread and mechanical dimensions.
• Cable length and cable construction.
• Connector type.
• Compatible signal converter.
• Measurement sensitivity and range.
• Target material and shaft diameter.
• Operating temperature and environmental conditions.
• Monitoring-system input requirements.

A sensor with the same nominal diameter may not be a direct replacement if its cable, connector, sensitivity, or converter requirements differ.

Key Advantages

Non-Contact Measurement

The sensor measures shaft movement without direct contact, avoiding mechanical wear between the probe and the rotating target.

Suitable for Critical Rotating Machinery

The PR6424 family is designed for monitoring applications involving turbines, compressors, pumps, and fans.

Static and Dynamic Measurement

The sensor family supports both static position measurement and dynamic displacement measurement, allowing it to contribute to different machinery monitoring functions.

High Measurement Sensitivity

The typical sensitivity of 4 V/mm and linearity of up to ±1.5% support precise displacement measurement when the probe and converter are correctly matched.

Compact Sensor Design

The supplied 16 mm head diameter makes the probe suitable for installations designed around the corresponding PR6424 sensor dimensions.

Integration with Machinery Monitoring Systems

With a compatible converter, the sensor can be incorporated into machinery protection and condition-monitoring architectures.

Industrial Monitoring Applications

The PR6424 family is intended for demanding rotating equipment applications where shaft movement and vibration are important operating parameters.

Technical FAQs

1. What is the Epro PR6424/010-030?

It is a non-contact eddy current sensor from the PR6424 family, designed for measuring shaft displacement and vibration in rotating machinery.

2. What is the sensor head diameter?

The supplied product specification identifies a 16 mm sensor head diameter.

3. What is the measurement principle?

It uses eddy current technology. Changes in the distance between the probe and a conductive metal target affect the sensor’s electromagnetic field and electrical characteristics.

4. What is the typical sensitivity?

The PR6424 16 mm sensor family has a typical sensitivity of 4 V/mm, with linearity of up to ±1.5%.

5. What is the static measurement range?

The published family specification gives a static measurement range of ±2.0 mm.

6. Can the sensor measure shaft vibration?

Yes. When used with a compatible converter and monitoring system, it can measure dynamic shaft displacement associated with vibration.

7. Does the sensor connect directly to a PLC?

It should not normally be connected directly to a standard PLC analog input as an unconditioned probe. A compatible signal converter or monitoring module is required to process the sensor signal.

8. Which machines can use the PR6424 series?

Typical applications include steam turbines, gas turbines, hydro turbines, compressors, pumps, and fans.

9. What is the weight of the PR6424/010-030?

The supplied listing weight is 0.2 kg. The PR6424 family specification also gives an approximate weight of 200 grams for the sensor with a 1-meter cable and without armor.

10. What should be checked before replacing an existing sensor?

Confirm the complete model number, sensor diameter, mounting arrangement, cable length, connector, compatible converter, and monitoring-system requirements.

Procurement and Maintenance Recommendations

When purchasing the Epro PR6424/010-030, verify the complete part number and confirm that the sensor matches the existing machinery monitoring system. Probe dimensions alone are not sufficient to establish electrical compatibility.

For replacement projects, check the sensor’s mechanical condition, cable insulation, connector contacts, mounting thread, and visible probe-tip condition. Request clear photographs of the product label and connection details where the exact configuration is uncertain.

During maintenance, inspect the probe mounting and cable routing regularly. Loose mounting hardware, damaged insulation, connector contamination, and incorrect probe gaps can affect measurement stability.

It is also useful to maintain records of the installed sensor model, converter type, cable length, initial gap, and monitoring channel settings. These records can simplify future troubleshooting and replacement work.

For critical machinery, any changes to probe position, converter configuration, or alarm thresholds should be reviewed by qualified machinery protection personnel. A sensor replacement should be followed by functional testing to confirm that the complete measurement channel is operating correctly.

Conclusion

The Epro PR6424/010-030 16 mm Eddy Current Sensor is designed for non-contact shaft displacement and vibration measurement in critical rotating machinery. Its PR6424 family specifications include a typical sensitivity of 4 V/mm, linearity of up to ±1.5%, and a static measurement range of ±2.0 mm.

With a supplied sensor head diameter of 16 mm and listing weight of 0.2 kg, this model is intended for integration into a compatible machinery monitoring system using the appropriate signal converter and connection accessories.

For industrial maintenance and procurement, confirming the complete model configuration and converter compatibility is essential to achieving reliable measurement performance.