Product Overview

The Epro PR6424/013-030+CON021 16 mm Eddy Current Sensor is a non-contact displacement measurement system designed for monitoring the condition and operating performance of critical rotating machinery. Manufactured under the EPRO product family associated with Emerson, this sensor assembly is used in applications where accurate shaft displacement, vibration, position, and eccentricity measurements are required.

The system combines a PR6424 16 mm eddy current probe with a CON021 signal converter. The probe detects changes in the distance between its sensing tip and a conductive target, while the converter processes the measurement signal into an electrical output suitable for connection to machinery monitoring and protection equipment.

Unlike contact-based measurement devices, an eddy current sensor does not need to physically touch the rotating shaft. This non-contact measurement principle makes it suitable for continuous monitoring of turbines, compressors, pumps, fans, and other large rotating machines.

The PR6424 series is designed for critical turbomachinery applications. Its 16 mm sensing head supports measurement of shaft vibration and displacement on suitable ferromagnetic targets. The standard measurement characteristics include approximately 4 V/mm sensitivity, a static measuring range of ±2.0 mm, and a dynamic measurement range of 0–1,000 μm.

The CON021 converter is an important part of the measurement chain. It conditions the probe signal and provides an electrical output for downstream monitoring equipment. The probe, cable, converter, and monitoring instrument must be treated as a matched measurement system to achieve reliable results.

This model is particularly relevant to industrial maintenance teams, machinery protection engineers, and operators responsible for monitoring rotating equipment.

Technical Specifications

Note: The supplied weight is for the listed sensor-and-converter assembly. Actual weight and cable configuration should be verified against the delivered product. Temperature limits and electrical output details should be confirmed using the exact probe and converter documentation.

Function and Working Principle

The PR6424/013-030+CON021 uses the eddy current principle to measure the distance between the sensor tip and a conductive target.

When the probe is supplied with its required electrical excitation, it generates an electromagnetic field near the target surface. This field induces eddy currents in the conductive material. Changes in the distance between the probe and the target affect the electromagnetic interaction, producing a measurable change in the sensor signal.

The CON021 converter processes this signal and provides an output that represents the measured displacement.

1. Non-Contact Displacement Measurement

The sensor measures shaft movement without making physical contact with the rotating component.

This is important for high-speed machinery, where a mechanical contact sensor could experience wear or interfere with the rotating surface. Non-contact measurement supports continuous observation while the machine is operating.

The sensor is suitable for measuring both static shaft position and dynamic shaft movement within its specified measurement range.

2. Shaft Vibration Monitoring

Rotating shafts may move away from their normal operating position because of imbalance, misalignment, bearing deterioration, mechanical looseness, or other abnormal conditions.

The PR6424 probe detects changes in the distance between the shaft surface and the sensor tip. These changes can be processed into vibration measurements by the connected monitoring system.

The resulting information helps maintenance engineers identify changes in machine behavior and investigate possible mechanical problems.

3. Signal Conversion

The CON021 is an eddy current signal converter designed for compatible EPRO sensor systems, including the PR6424 series.

It conditions the probe signal and provides an electrical output for downstream monitoring equipment. The converter supports the measurement chain between the physical sensing element and the machinery monitoring system.

The probe and converter must be correctly matched. Using an incompatible converter or incorrect measurement range can result in inaccurate readings or unsuitable output signals.

4. Shaft Position and Eccentricity Measurement

In addition to vibration, the system can measure shaft position and eccentricity.

Shaft position measurements help operators understand the relative position of rotating components. Eccentricity measurements can reveal variations in the distance between the shaft centerline and the measurement reference.

These measurements are valuable in turbines, compressors, and other machines where shaft movement can affect mechanical clearances and operating stability.

5. Speed and Keyphasor-Related Monitoring

Depending on the monitoring configuration and target arrangement, an eddy current measurement system can also support speed and reference-position measurements.

These signals may be used by machinery monitoring equipment for rotational speed analysis, phase reference, and vibration diagnostics.

The exact functionality depends on the installed sensor configuration, target geometry, and monitoring-system capabilities.

Role in Industrial Machinery Monitoring Systems

The PR6424/013-030+CON021 is designed to function as part of a complete machinery monitoring and protection system.

It does not normally operate as an independent monitoring controller. Instead, it supplies measurement information to compatible signal-processing and monitoring equipment.

1. Integration with Machinery Protection Systems

In critical rotating machinery, vibration and shaft displacement measurements are often connected to dedicated machinery protection systems.

These systems continuously evaluate sensor signals and compare operating conditions with configured alarm and trip limits.

If the measured shaft movement exceeds an established threshold, the monitoring system can generate an alarm or initiate a protective response according to the plant’s protection strategy.

2. Integration with DCS Platforms

A distributed control system can receive relevant machinery condition information from monitoring equipment.

Operators can use this information alongside process variables such as pressure, temperature, flow, and motor load to understand overall equipment performance.

The PR6424 sensor itself is not a DCS controller. It supplies measurement signals through the compatible converter and monitoring equipment.

3. Condition Monitoring and Predictive Maintenance

Continuous shaft displacement measurements can help maintenance teams identify changes in rotating machinery before they develop into more serious failures.

By reviewing vibration trends and displacement data, engineers can investigate possible bearing problems, imbalance, misalignment, and other mechanical abnormalities.

The sensor provides measurement data; accurate diagnosis requires suitable monitoring hardware, signal analysis, operating history, and engineering interpretation.

4. Turbine Protection

Steam, gas, and hydro turbines operate under demanding mechanical and thermal conditions. Shaft vibration and position measurements are important for evaluating rotor behavior and protecting critical rotating components.

The PR6424 series is designed for this type of machinery monitoring application, subject to the appropriate probe configuration and installation requirements.

Industrial Applications

The PR6424/013-030+CON021 can be used in industrial environments where non-contact shaft displacement and vibration monitoring are required.

1. Steam Turbines

Steam turbines operate at high rotational speeds and require continuous monitoring of shaft behavior.

The eddy current sensor can measure radial and axial shaft movement, providing information for turbine condition monitoring and protection systems.

These measurements help engineers evaluate changes in rotor vibration and shaft position during startup, normal operation, and shutdown.

2. Gas Turbines

Gas turbines are critical assets in power generation and industrial processing facilities.

The PR6424 measurement system can support monitoring of shaft vibration, displacement, and position when installed with a suitable monitoring arrangement.

Continuous measurement helps maintenance teams investigate abnormal vibration patterns and changes in rotor behavior.

3. Industrial Compressors

Large compressors are widely used in petrochemical plants, refineries, gas processing facilities, and manufacturing operations.

Shaft vibration and displacement measurements are important for evaluating compressor operating conditions.

The sensor can provide non-contact measurements for monitoring systems used to detect changes associated with rotor imbalance, misalignment, and bearing-related problems.

4. Pumps

Large industrial pumps may operate continuously under changing hydraulic and mechanical loads.

Monitoring shaft movement can help identify changes in mechanical condition and support maintenance planning.

The sensor is suitable for applications where its measuring range, target material, and installation arrangement meet the pump’s requirements.

5. Industrial Fans

Large fans used in power plants, cement facilities, and process industries may require continuous shaft vibration monitoring.

An eddy current sensor can provide displacement measurements for compatible rotating shafts and machinery protection systems.

6. Power Generation Equipment

Power generation facilities depend on reliable operation of turbines, generators, compressors, and auxiliary rotating equipment.

The PR6424 system can form part of a wider machinery monitoring strategy, providing shaft movement information for condition assessment and equipment protection.

Installation and System Integration

Correct installation is essential for obtaining stable and repeatable measurement results.

1. Verify the Complete Measurement Chain

Before installation, confirm that the PR6424 probe, CON021 converter, cable, connectors, and monitoring equipment are compatible.

The complete catalog number should be checked because different PR6424 configurations can have different mechanical dimensions, cable arrangements, and measurement characteristics.

Do not assume that every PR6424 probe can be connected to every converter configuration without checking the manufacturer’s documentation.

2. Prepare the Measurement Target

The PR6424 system is designed for measurement against suitable ferromagnetic steel targets.

Target material and surface condition affect measurement performance. The target should be suitable for the sensor’s specified calibration characteristics.

Surface irregularities, excessive runout, and unsuitable target materials may affect measurement accuracy.

3. Set the Initial Air Gap

The sensor must be positioned at the correct initial gap from the target surface.

The PR6424 series has a nominal center air gap of approximately 2.7 mm under its standard measurement configuration.

The actual installation gap should be established according to the manufacturer’s calibration and setup instructions. Incorrect positioning may reduce the available linear measuring range or cause the signal to operate outside its intended range.

4. Secure the Sensor Mechanically

Install the sensor using the specified threaded mounting arrangement and suitable mechanical supports.

The mounting location should minimize unwanted movement and vibration of the sensor body itself. Loose brackets or unstable mounting structures can introduce measurement errors.

Ensure that the sensor tip has sufficient clearance from the rotating shaft throughout the operating cycle.

5. Route and Protect the Cable

The sensor cable should be routed away from high-voltage power cables and strong electromagnetic interference sources where possible.

Avoid sharp bends, excessive pulling forces, and mechanical damage. Follow the manufacturer’s minimum bending-radius requirements.

The cable and connector should be protected against oil, heat, vibration, and other environmental conditions appropriate to the installation.

6. Connect the CON021 Converter

Connect the probe to the compatible CON021 converter according to the wiring diagram.

The converter requires the specified DC supply and provides the corresponding measurement output. Supply polarity, terminal connections, grounding, and output configuration must be checked before energizing the system.

7. Verify Signal Performance

After installation, check the initial air gap, output signal, measurement stability, and monitoring-system scaling.

Compare the sensor readings with the expected shaft position and operating conditions. Confirm that alarm and trip thresholds are configured according to the machinery protection requirements.

Compatible System Components

The PR6424/013-030+CON021 is part of a measurement chain that may include the following equipment.

The components listed above are examples of equipment used in a complete measurement installation. They are not necessarily included in every PR6424/013-030+CON021 package.

Alternative Models and Replacement Considerations

When replacing an existing EPRO sensor, the full model number and measurement configuration should be checked.

Before selecting a replacement, compare:

• Complete probe model and suffix.
• Sensor head diameter.
• Probe length and mounting thread.
• Cable length and connector type.
• Armored or non-armored cable arrangement.
• Converter model and measurement range.
• Output voltage configuration.
• Sensitivity and linearity.
• Target material and shaft dimensions.
• Monitoring-system input requirements.

A probe with the same 16 mm sensing diameter is not automatically a direct replacement. The mechanical and electrical characteristics of the complete measurement chain must be verified.

Key Advantages

Non-Contact Measurement

The sensor measures shaft movement without physical contact, avoiding direct mechanical wear at the sensing point.

16 mm Sensing Head

The PR6424 series uses a 16 mm sensing head designed for suitable large-shaft machinery applications.

Displacement and Vibration Monitoring

The measurement system supports static shaft position and dynamic displacement monitoring within its specified range.

Signal Conditioning with CON021

The matched converter processes the probe signal for connection to compatible machinery monitoring equipment.

Industrial Machinery Applications

The system is designed for monitoring critical rotating equipment such as turbines, compressors, pumps, and fans.

Continuous Condition Monitoring

When integrated into a suitable monitoring system, the sensor can provide ongoing measurement information for machinery diagnostics and maintenance planning.

Established EPRO Measurement Technology

The PR6424 family is used in industrial machinery monitoring applications where reliable non-contact displacement measurement is required.

Technical FAQs

1. What is the Epro PR6424/013-030+CON021?

It is a 16 mm eddy current displacement measurement system consisting of a PR6424 sensor and a compatible CON021 signal converter.

2. What is the main function of this sensor?

Its main function is to measure shaft displacement, vibration, position, and eccentricity without physical contact with the rotating target.

3. What is the sensor head diameter?

The sensor head diameter is 16 mm.

4. What is the measuring range?

The standard PR6424 configuration has a static measuring range of ±2.0 mm and a dynamic range of 0–1,000 μm. Confirm the exact ordering configuration before applying these values to a specific installation.

5. What is the sensitivity of the PR6424 sensor?

The typical sensitivity is approximately 4 V/mm, with a specified linearity error of no more than ±1.5% under the applicable standard conditions.

6. What is the purpose of the CON021 converter?

The CON021 processes the eddy current probe signal and provides an electrical output for compatible machinery monitoring equipment.

7. Which machines can use this sensor?

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

8. Does the sensor contact the rotating shaft?

No. It uses an eddy current measurement principle and operates without direct contact with the shaft surface.

9. What target material is required?

The standard PR6424 measurement specification identifies ferromagnetic steel as the target material. The target surface and material should meet the manufacturer’s requirements.

10. What should be checked before purchasing a replacement?

Verify the complete model number, sensor dimensions, probe length, cable arrangement, converter compatibility, measuring range, and connector type. Also confirm the condition of the sensor and whether the converter is included.

Procurement and Maintenance Recommendations

When purchasing the Epro PR6424/013-030+CON021, verify that the product includes the required sensor and CON021 converter configuration. Some suppliers list the probe and converter separately, while others offer them as a combined measurement assembly.

For replacement projects, compare the complete ordering code with the installed sensor. Pay particular attention to the probe’s mechanical dimensions, cable length, connector, and converter compatibility.

For used or refurbished products, request photographs of the probe identification label, converter model, cable, and connectors. Where possible, obtain test information confirming that the sensor and converter operate as a matched system.

During maintenance, inspect the probe mounting, cable condition, connector security, and converter wiring. Check for damaged insulation, loose connections, excessive cable bending, and mechanical movement of the mounting bracket.

Measurement performance should also be reviewed periodically. Compare sensor readings with operating history and other machinery condition data. If readings become unstable, investigate the target surface, mounting gap, cable condition, electrical interference, and converter configuration before replacing the complete assembly.

Conclusion

The Epro PR6424/013-030+CON021 16 mm Eddy Current Sensor is a non-contact displacement measurement system designed for monitoring critical rotating machinery. Combining a PR6424 16 mm probe with a CON021 signal converter, it supports shaft vibration, displacement, position, and eccentricity measurement in suitable industrial applications.

With a typical sensitivity of 4 V/mm, a static measuring range of ±2.0 mm, and a dynamic range of 0–1,000 μm, the system can provide important measurement information for machinery monitoring and protection applications.

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