1. Product Overview

The Epro PR6424/005-021 16 mm Eddy Current Sensor is an industrial non-contact sensor designed for displacement measurement and rotating machinery condition monitoring. Belonging to the EPRO PR6424 family, this type of sensor is used in measurement systems that monitor shaft movement, radial and axial displacement, eccentricity, and other mechanical characteristics of rotating equipment.

With a specified sensor head diameter of 16 mm and a stated product weight of approximately 0.2 kg, the PR6424/005-021 is relevant to industrial installations where a probe must measure the distance between its sensing tip and a suitable metallic target without direct contact. This measurement principle helps avoid contact wear and enables continuous monitoring of moving machinery components.

Typical applications for the PR6424 sensor family include steam turbines, gas turbines, hydro turbines, compressors, pumps, fans, and other rotating equipment. In these applications, changes in shaft position or vibration can provide valuable information about machine operating conditions and potential mechanical problems.

The sensor is generally used as part of a complete measurement system. Depending on the configuration, this system may include the probe, an extension cable, a compatible signal converter, and a machinery monitoring module. The probe detects changes in the gap between the sensing tip and the target, while the associated electronics condition the signal for monitoring and analysis.

For industrial buyers and maintenance engineers, it is important to confirm the exact configuration of the PR6424/005-021 before purchasing or replacing a sensor. Mechanical dimensions, cable length, connector arrangement, converter compatibility, and calibration characteristics should be checked against the applicable product documentation.

2. Technical Specifications

The following table combines the supplied product details with typical PR6424 family specifications. Family-level values are provided as engineering reference information and should be verified for the exact model configuration.

Important specification note: The 16 mm sensor head diameter and approximate 0.2 kg weight are based on the information supplied for this product. Other values are PR6424 family references, not independently verified specifications for every PR6424/005-021 configuration. Confirm the precise ordering code and manufacturer’s documentation before using these values for engineering approval or procurement.

3. Function and Working Principle

3.1 Non-Contact Eddy Current Measurement

The PR6424 sensor family uses the eddy current principle to measure the distance between a probe and a suitable conductive target.

The probe generates an alternating electromagnetic field near its sensing tip. When a conductive metallic target enters this field, eddy currents are induced in the target surface. These currents affect the electrical characteristics of the probe.

As the distance between the probe and the target changes, the probe response changes accordingly. Compatible signal conditioning equipment converts this response into a measurement signal representing the gap or relative displacement.

Because the measurement does not require physical contact, the technology is suitable for monitoring rotating shafts and other moving components.

3.2 Shaft Displacement Measurement

Shaft displacement monitoring helps determine how a rotating shaft moves relative to a fixed reference point. Changes in shaft position may result from load variations, bearing clearance, thermal expansion, mechanical alignment, or changes in operating conditions.

When mounted in an appropriate position, the sensor detects changes in the gap between its sensing tip and the shaft surface. The measurement system can then use the signal to monitor relative shaft movement.

3.3 Shaft Vibration Monitoring

Shaft vibration is an important indicator of rotating machinery condition. Changes in vibration behavior may be associated with imbalance, misalignment, mechanical looseness, bearing-related problems, or other equipment issues.

A properly installed eddy current probe can measure dynamic shaft displacement. The connected monitoring equipment processes the resulting signal and enables engineers to evaluate vibration trends and investigate abnormal behavior.

3.4 Signal Conditioning

The probe is normally part of a larger measurement chain rather than a complete standalone monitoring system. Depending on the configuration, the system may require a compatible signal converter to condition the probe response and provide a usable output.

The complete arrangement may include:

• PR6424/005-021 sensor probe
• Compatible extension cable, where required
• EPRO signal converter
• Machinery monitoring module
• Operator interface or machinery protection system

The exact converter, cable, and connector configuration must be confirmed before system integration.

4. Role in Industrial Control and Machinery Protection Systems

The Epro PR6424/005-021 provides measurement information for use by compatible monitoring equipment. Alarm evaluation, protection logic, and shutdown functions are handled by the connected system according to the plant’s engineering design.

4.1 Continuous Condition Monitoring

Rotating machinery in power generation and process industries often operates continuously under changing load and environmental conditions. Continuous displacement measurement allows maintenance teams to track shaft behavior during startup, normal operation, load changes, and shutdown.

The sensor can contribute measurement data that is evaluated alongside other machinery parameters to help identify changes in operating condition.

4.2 Alarm and Protection Integration

When connected to suitable monitoring equipment, sensor measurements can be used as inputs to configurable alarm and protection functions. Engineering teams determine the appropriate alarm thresholds and protective responses according to equipment requirements and applicable standards.

The probe itself should not be considered an independent alarm or shutdown controller.

4.3 Integration With Plant Automation

Processed measurement data may be incorporated into a broader industrial automation system through compatible monitoring equipment and signal interfaces.

This can allow engineers to compare shaft movement with operating variables such as speed, temperature, pressure, and load. Combined information supports troubleshooting and helps maintenance teams evaluate whether observed changes may be related to mechanical or process conditions.

5. Industrial Applications

5.1 Steam Turbines

Steam turbines operate at high speeds and require careful monitoring of shaft displacement and vibration. A properly configured eddy current measurement system can provide information about shaft behavior and support condition monitoring.

5.2 Gas Turbines

Gas turbines operate under demanding thermal and mechanical conditions. Non-contact displacement measurements can contribute to monitoring arrangements that evaluate rotor movement and changes in vibration.

5.3 Hydro Turbines

Hydroelectric turbine-generator assemblies may experience varying loads and operating conditions. Shaft displacement monitoring can help assess shaft alignment and mechanical stability.

5.4 Industrial Compressors

Compressors used in refineries, gas processing facilities, petrochemical plants, and manufacturing operations often require continuous machinery monitoring. Eddy current sensors can provide shaft displacement measurements for suitable compressor monitoring systems.

5.5 Pumps and Fans

Industrial pumps and fans are widely used in water treatment, power generation, chemical processing, and general manufacturing. Where the machine design calls for shaft displacement measurement, a compatible eddy current probe can contribute useful operating data.

5.6 General Rotating Machinery

The PR6424 family may also be considered for other suitable rotating equipment. Final selection depends on target material, shaft diameter, mounting geometry, environmental conditions, and the required measurement performance.

6. Installation and System Integration

Correct installation is essential for reliable and repeatable measurement results.

6.1 Confirm the Exact Model

Before installation, verify the complete PR6424/005-021 ordering code and the manufacturer’s associated documentation. Confirm the probe length, mounting thread, cable type, connector arrangement, and compatible signal converter.

Do not assume that all PR6424 variants are mechanically or electrically interchangeable simply because they share the same product family.

6.2 Prepare the Mounting Location

Select a stable mounting position that allows the probe to face the intended target surface. The mounting structure should minimize unintended movement and provide adequate clearance around the sensor body and cable connection.

Follow the specified mechanical installation requirements for the exact probe configuration.

6.3 Set the Initial Air Gap

The gap between the probe tip and target determines the operating point within the measurement range. Set the gap according to the applicable installation instructions and calibration procedure.

A typical family-level air-gap value should not be used as a substitute for the manufacturer’s instructions for the specific model.

6.4 Check the Target Material

Eddy current sensor performance depends on target material and geometry. Verify that the shaft material, diameter, surface condition, and measurement location are suitable for the selected measurement system.

If the target material or geometry differs from the standard reference arrangement, additional calibration or compatibility checks may be required.

6.5 Connect the Signal Conditioning Equipment

Use the specified cable and compatible converter. Verify the connector interface, cable length, grounding arrangement, and signal requirements before commissioning.

Route sensor wiring in accordance with the manufacturer’s recommendations and avoid unnecessary exposure to electrical interference.

6.6 Commission the System

After installation, verify the probe gap, signal response, converter configuration, and monitoring channel settings. Confirm that measurements are consistent with the expected operating conditions.

Any associated alarm and protection functions should be checked as part of the overall machinery monitoring system commissioning process.

7. Compatible System Components

The PR6424/005-021 should be evaluated as part of a complete measurement chain. Compatibility depends on the sensor configuration and the input requirements of the receiving equipment.

Before purchasing additional components, verify the complete measurement chain. Connector type, cable configuration, converter compatibility, and calibration requirements should all be confirmed.

8. Recommended Alternative Models

The following models are examples for comparison within the EPRO sensor portfolio. They are not guaranteed direct replacements for the PR6424/005-021.

A replacement decision should consider the complete part number, probe dimensions, cable and connector arrangement, calibration, converter compatibility, target material, and operating environment. Shared family names or similar sensor diameters do not guarantee interchangeability.

9. Key Advantages

Non-Contact Measurement

The sensor measures the gap between the probe and target without physical contact. This makes it suitable for monitoring rotating components without introducing contact wear during normal measurement.

Suitable for Rotating Machinery Monitoring

The PR6424 family is intended for displacement and vibration measurement in applications involving turbines, compressors, pumps, fans, and other rotating machinery.

Multiple Monitoring Applications

Depending on the overall system configuration, measurements can support shaft displacement, position, vibration, and eccentricity monitoring.

Compact Sensor Head

The specified 16 mm sensor head diameter provides a useful dimensional reference for installation planning and replacement evaluation.

Integration With Industrial Monitoring Equipment

When paired with compatible signal conditioning and monitoring equipment, the sensor can contribute to a larger machinery monitoring and protection arrangement.

Support for Maintenance Planning

Continuous measurement data can help maintenance personnel identify changes in shaft behavior, investigate unusual trends, and prioritize inspections based on equipment condition.

10. Technical FAQs

Q1. What is the Epro PR6424/005-021?

It is a 16 mm eddy current sensor in the EPRO PR6424 product family, intended for non-contact displacement and rotating machinery monitoring applications.

Q2. What is the sensor head diameter?

The supplied product information specifies a sensor head diameter of 16 mm.

Q3. What is the weight of the PR6424/005-021?

The supplied product information lists the weight as approximately 0.2 kg. Confirm whether this figure includes the cable and accessories when checking shipping or installation requirements.

Q4. How does an eddy current sensor measure displacement?

The probe generates an alternating electromagnetic field. A conductive target affects the field and changes the probe response. Compatible electronics process this response to determine the relative gap or displacement.

Q5. Can it be used for shaft vibration monitoring?

The PR6424 family is intended for non-contact shaft displacement and vibration monitoring. The probe must be used with compatible signal conditioning and monitoring equipment.

Q6. What is the typical measurement range?

PR6424 family documentation lists a typical static range of ±2.0 mm and a dynamic range of 0–1,000 μm for a standard configuration. Verify the specifications applicable to the exact PR6424/005-021 model before design or procurement.

Q7. Does the sensor need a signal converter?

A compatible signal converter is generally part of the complete PR6424 measurement system. The exact converter depends on the probe configuration and receiving monitoring equipment.

Q8. Is the PR6424/005-021 interchangeable with other PR6424 models?

Not necessarily. Different suffixes can indicate different configurations. Check mechanical dimensions, cable and connector details, calibration characteristics, and converter compatibility before replacing one variant with another.

Q9. Where is this sensor typically used?

Potential applications include power generation, oil and gas, petrochemical processing, industrial manufacturing, and other facilities that monitor critical rotating equipment.

Q10. What information should be confirmed before ordering?

Confirm the complete part number, sensor head diameter, probe length, mounting thread, cable length, connector type, signal converter, target material, operating environment, and required measurement performance.

11. Conclusion

The Epro PR6424/005-021 16 mm Eddy Current Sensor is designed for non-contact displacement measurement in industrial machinery monitoring applications. Its stated sensor head diameter of 16 mm and approximate weight of 0.2 kg provide useful starting points for product identification and installation planning.

When integrated with compatible signal conditioning and monitoring equipment, the sensor can contribute to shaft displacement, vibration, position, and eccentricity monitoring in suitable rotating machinery. These measurements can support equipment condition assessment, maintenance planning, and the broader machinery protection strategy.

For replacement procurement or new installations, confirm the exact PR6424/005-021 configuration and its compatibility with the existing measurement chain. Verifying mechanical dimensions, cable and connector arrangements, converter requirements, and applicable technical specifications helps reduce integration risk and supports reliable operation.