Product Overview

The Epro PR6424/010-120+CON011 16 mm Eddy Current Sensor is designed for non-contact measurement of shaft vibration, displacement, and position in industrial rotating machinery. It belongs to the PR6424 eddy current sensor family, which is used in machinery condition monitoring and protection applications involving turbines, compressors, pumps, fans, and other critical rotating equipment.

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 the technology suitable for monitoring rotating shafts where continuous measurement is required and direct mechanical contact would be impractical.

The PR6424 sensor detects changes in the electromagnetic field generated at its probe tip. When a conductive shaft surface approaches or moves away from the probe, the electrical characteristics of the sensing circuit change. A compatible signal converter processes this response and provides an electrical output that can be interpreted by a machinery monitoring system.

The PR6424 family uses a 16 mm sensor tip and is intended for applications requiring shaft displacement and vibration measurements. Depending on the complete configuration, it can support measurements associated with radial vibration, axial movement, shaft position, eccentricity, and rotational speed or keyphasor-related applications.

The product designation PR6424/010-120+CON011 identifies a specific probe and converter arrangement. The probe and converter must be treated as a matched measurement configuration. Cable length, connector type, probe construction, and converter compatibility should be checked against the complete ordering information before installation or replacement.

In industrial machinery protection systems, the sensor is one part of a wider measurement chain. Reliable monitoring also depends on the converter, extension cable where applicable, monitoring module, mounting arrangement, and correct configuration of the measurement channel.

Technical Specifications

Note: The specifications above combine the supplied product information with general PR6424 family specifications. Exact temperature limits, cable configuration, connector arrangement, and converter characteristics must be confirmed against the complete product code and applicable documentation.

Function and Working Principle

The PR6424 uses the eddy current principle to measure the distance between the probe and a conductive metal target. Its operation is based on electromagnetic interaction rather than physical contact.

1. Electromagnetic Field Generation

An electrical excitation signal is applied to the sensing coil inside the probe. This creates an alternating electromagnetic field around the sensor tip.

When the probe is positioned near a conductive shaft, the electromagnetic field induces small circulating electrical currents, known as eddy currents, in the target material.

2. Detection of Shaft Movement

The strength of the eddy currents changes when the distance between the probe and the shaft changes. This affects the electrical characteristics of the probe circuit.

As the shaft moves closer to the probe, the sensor response changes in one direction. When the shaft moves farther away, the response changes in the opposite direction.

By measuring these changes, the system can determine variations in the distance between the probe and the target surface.

3. Signal Conversion

The probe’s raw sensing response is processed by a compatible converter. In the PR6424/010-120+CON011 configuration, the CON011 designation identifies the associated converter arrangement.

The converter conditions the measurement signal and provides an output suitable for connection to compatible machinery monitoring equipment.

The complete measurement chain must be configured with the correct probe, cable, converter, and monitoring channel. Using an incompatible converter or an incorrectly matched cable can result in measurement errors.

4. Static Displacement Measurement

Static displacement measurements provide information about the relative position of a shaft or another conductive target.

This information is useful for monitoring shaft position, axial movement, mechanical clearance, and changes in the operating position of rotating equipment.

The PR6424 family has a documented static measurement range of ±2.0 mm under the specified measurement conditions.

5. Dynamic Vibration Measurement

Dynamic measurements identify changes in shaft position over time. These variations can be used to evaluate shaft vibration and rotating machinery behavior.

The monitoring system can analyze the resulting signal to identify changes in vibration amplitude and other operating characteristics.

A correctly installed sensor can provide continuous measurement without direct mechanical contact with the rotating shaft.

Role in Industrial Machinery Monitoring Systems

The PR6424/010-120+CON011 is designed to function as part of a machinery monitoring arrangement rather than as a standalone control device. It provides measurement information that can be used by monitoring equipment, protection systems, and maintenance personnel.

Turbine Monitoring

Steam and gas turbines operate at high rotational speeds and require continuous monitoring of critical shaft conditions. Eddy current sensors can be installed near selected bearing locations to measure shaft vibration and relative displacement.

The measurement data can help operators identify changes in rotor behavior, mechanical clearances, and operating conditions.

Compressor Protection

Industrial compressors are often critical to continuous production. Shaft vibration and displacement monitoring can provide information about rotor movement and possible mechanical changes.

When integrated with a suitable protection system, the sensor measurement can contribute to alarm and shutdown strategies.

Pump Condition Monitoring

Large industrial pumps may operate continuously in power generation, chemical processing, oil and gas, and water treatment facilities.

The PR6424 sensor family can be used in appropriate pump monitoring arrangements to measure shaft displacement and vibration, helping maintenance teams assess mechanical operating conditions.

PLC and DCS Integration

The sensor measurement chain may be connected to a compatible machinery monitoring module. The resulting information can then be made available to a distributed control system or plant monitoring platform.

The exact interface depends on the converter and monitoring hardware. The probe should not be connected directly to a general-purpose PLC analog input unless the required signal conditioning and electrical interface are provided.

Industrial Applications

1. Steam Turbines

Steam turbines contain high-speed rotating components that require accurate monitoring of shaft movement and vibration.

PR6424 sensors can be positioned near selected bearing locations to measure shaft displacement. This information can help identify changes in rotor behavior and support machinery protection strategies.

Typical monitoring objectives include:

• Radial shaft vibration measurement.
• Shaft position monitoring.
• Rotor eccentricity assessment.
• Detection of changes in operating vibration.
• Support for turbine condition monitoring.

2. Gas Turbines

Gas turbines operate under demanding thermal and mechanical conditions. Monitoring systems are used to observe shaft behavior and identify abnormal operating trends.

A suitable PR6424 configuration can contribute to non-contact shaft measurement in compatible monitoring installations. Probe temperature limits and mounting conditions must be checked carefully for the specific location.

3. Industrial Compressors

Centrifugal and other high-speed compressors depend on stable rotor operation. Shaft displacement measurements can help maintenance teams evaluate changes in vibration and mechanical condition.

The sensor can be used as part of a monitoring arrangement for compressor bearings and other suitable measurement locations.

4. Industrial Pumps

Large pumps used in process plants and power stations may require continuous monitoring to support equipment reliability.

Non-contact displacement measurement can provide information about shaft movement without adding mechanical contact to the rotating assembly.

5. Fans and Blowers

Large industrial fans and blowers can experience vibration caused by imbalance, mechanical looseness, alignment problems, or bearing-related changes.

A suitable shaft displacement monitoring arrangement can help identify abnormal vibration trends and support maintenance planning.

Installation and System Integration

Correct installation is essential for obtaining reliable measurement results. The probe position, target material, air gap, cable routing, and converter configuration all influence measurement performance.

1. Confirm the Complete Model Configuration

Before installation, verify the complete product designation:

• PR6424 probe model.
• Probe mechanical configuration.
• Sensor head and mounting thread.
• Cable type and length.
• Connector arrangement.
• CON011 converter configuration.

Do not assume that every PR6424 probe uses the same cable, connector, or mechanical dimensions. Different ordering codes can represent different physical arrangements.

2. Select the Correct Mounting Position

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

For radial vibration measurement, the sensor is normally positioned near the shaft surface at an appropriate bearing location. For axial displacement measurement, the probe arrangement must be designed for the relevant shaft target surface.

The installation should provide a stable mechanical mounting point and prevent unwanted movement of the probe body.

3. Set the Initial Air Gap

The distance between the probe tip and the target surface must be adjusted according to the manufacturer’s installation procedure.

The PR6424 family documentation specifies a nominal center air gap of approximately 2.7 mm for the applicable measurement configuration.

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

4. Verify Target Material and Surface

The PR6424 is designed for measurement against conductive ferromagnetic targets. The documented reference material is 42CrMo4 steel.

Target material, shaft diameter, surface condition, and geometry can affect the measurement response. The minimum target area and installation offsets must be considered during mechanical design.

5. Connect the Probe and Converter

Connect the probe cable and associated converter according to the manufacturer’s wiring instructions.

The probe, cable, and converter must form a compatible measurement chain. Avoid unnecessary cable extensions, incorrect connector adapters, or unapproved substitutions.

Keep sensor wiring away from high-current conductors and sources of electrical interference where required by the installation design.

6. Configure the Monitoring Channel

After installation, configure the associated monitoring channel with the correct sensor type, measurement range, sensitivity, and signal scaling.

The monitoring system should be set up according to the actual probe and converter specifications rather than assumed values from another PR6424 configuration.

7. Perform Functional Verification

Before returning the machinery to service, verify:

• Correct probe installation and mechanical stability.
• Initial air gap.
• Cable and connector condition.
• Converter power and output.
• Monitoring channel configuration.
• Signal polarity and scaling.
• Measurement stability.
• Alarm and protection settings.

Record the installation details and final channel configuration for future maintenance.

Compatible System Components

The PR6424/010-120+CON011 operates as part of a measurement chain. The following components may be involved in a compatible installation.

The components listed are examples of a typical monitoring arrangement. They are not necessarily included in the supplied product package.

Alternative Models and Replacement Considerations

The PR6424 family includes different mechanical and electrical configurations. When selecting a replacement, the complete model code is more important than the sensor family name alone.

Before replacing the PR6424/010-120+CON011, compare:

• Probe head diameter.
• Complete probe ordering code.
• Probe length and mounting thread.
• Cable length and cable construction.
• Connector type.
• Converter model.
• Measurement sensitivity and range.
• Initial air gap.
• Operating temperature.
• Monitoring module input requirements.

A probe with the same 16 mm head diameter is not necessarily a direct replacement. The electrical characteristics and mechanical arrangement must also match.

Key Advantages

Non-Contact Measurement

The eddy current principle allows the sensor to measure shaft movement without physical contact. This is useful for continuously rotating machinery.

Shaft Displacement Monitoring

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

Suitable for Critical Rotating Equipment

The sensor family is intended for applications involving turbines, compressors, pumps, and fans where machinery condition information is important.

High Measurement Sensitivity

The documented PR6424 sensitivity is 4 V/mm with a specified linearity of ±1.5% for the applicable configuration.

Continuous Monitoring Capability

When integrated with compatible monitoring equipment, the sensor can provide continuous measurement information for machinery condition assessment.

Industrial Sensor Construction

The PR6424 family uses a stainless steel sleeve and PTFE-insulated cable in the documented configuration. These materials are intended for industrial sensor applications within the specified environmental limits.

Flexible Measurement Applications

Depending on the installation and monitoring arrangement, the sensor can support radial and axial displacement, shaft position, eccentricity, and vibration-related measurements.

Technical FAQs

1. What is the Epro PR6424/010-120+CON011?

It is a 16 mm eddy current sensor configuration associated with a CON011 signal converter. It is designed for non-contact measurement of shaft displacement and vibration in rotating machinery.

2. What is the sensor head diameter?

The sensor head diameter is 16 mm.

3. What is an eddy current sensor used for?

An eddy current sensor measures the distance between a probe and a conductive target without physical contact. In rotating machinery, it is commonly used for shaft vibration, displacement, and position monitoring.

4. What is the typical sensitivity of the PR6424 series?

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

5. What is the static measurement range?

The PR6424 family documentation specifies a static measurement range of ±2.0 mm under the stated measurement conditions.

6. What is the difference between the probe and the CON011 converter?

The probe detects changes in the distance between its tip and the conductive target. The converter processes the probe response and provides a suitable output for compatible monitoring equipment.

7. Can the PR6424 be used for turbine monitoring?

Yes. The PR6424 family is designed for critical rotating machinery applications, including steam and gas turbines. Its use must follow the required installation, temperature, and monitoring-system specifications.

8. Can this sensor measure both vibration and displacement?

The PR6424 measurement technology supports static displacement and dynamic shaft movement measurements. The monitoring channel must be configured appropriately for the intended measurement.

9. Can it be connected directly to a PLC?

Not necessarily. The probe requires its compatible converter and appropriate signal-conditioning interface. The resulting output must match the PLC input requirements.

10. What should be checked before purchasing a replacement?

Confirm the full probe code, sensor diameter, mounting thread, cable length, connector type, converter model, measurement characteristics, and physical condition. Matching only the PR6424 family name is insufficient.

Procurement and Maintenance Recommendations

When purchasing the Epro PR6424/010-120+CON011, verify that the supplied probe and converter match the required measurement configuration. Check the full product code and inspect the sensor label, connector, cable, and probe body.

For used or surplus equipment, request clear photographs of the actual unit. Inspect the probe tip for mechanical damage, check the cable for cuts or deformation, and examine connectors for contamination or corrosion.

The supplied weight of 0.32 kg should be treated as the product listing weight for the stated configuration. Confirm the actual package contents and shipping weight separately when arranging international transportation.

During maintenance, keep the probe tip and connector clean and avoid bending the cable below its specified minimum radius. Inspect the mounting arrangement and cable routing for looseness, abrasion, and exposure to excessive temperature.

If a monitoring channel shows an unexpected signal, check the probe gap, cable connections, converter compatibility, grounding, and channel configuration before concluding that the sensor itself has failed.

For critical turbine and compressor applications, replacement work should be performed according to the machinery protection system’s maintenance procedures. Record the original sensor configuration and measurement settings before removing the installed unit.

Conclusion

The Epro PR6424/010-120+CON011 16 mm Eddy Current Sensor is intended for non-contact shaft displacement and vibration monitoring in industrial rotating machinery. Its PR6424 sensor technology supports static and dynamic measurements, while the associated CON011 converter forms part of the signal-conditioning arrangement.

With a 16 mm sensor head and documented PR6424 family characteristics such as 4 V/mm sensitivity and a ±2.0 mm static measurement range, this configuration is relevant to machinery monitoring applications involving turbines, compressors, pumps, and fans.

For maintenance and replacement projects, confirming the complete probe code, converter compatibility, cable arrangement, and installation requirements is essential for maintaining reliable measurement performance.