Product Overview

The EPRO PR6424/01+CON011 16 mm Eddy Current Sensor is a non-contact displacement measurement system designed for monitoring the condition and operating behavior of critical rotating machinery. It combines a PR6424 series eddy current sensor with a CON011 signal converter to measure shaft displacement, vibration, position, and other mechanical parameters in industrial equipment.

Manufactured within the EPRO product portfolio, the PR6424 series is commonly associated with machinery monitoring applications involving steam turbines, gas turbines, compressors, pumps, and fans. These machines often operate under continuous mechanical loads and require reliable monitoring to identify abnormal shaft movement and changing operating conditions.

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

The PR6424 sensor uses a 16 mm sensing head and is designed to detect both static and dynamic displacement. When installed with a compatible signal converter, the measurement signal can be conditioned for use by machinery protection and monitoring equipment.

The CON011 converter forms part of the measurement chain. It receives the sensor signal and provides the corresponding conditioned output for integration into an appropriate monitoring system. Correct matching of the probe, converter, cable, and monitoring equipment is essential for accurate measurement.

The PR6424/01+CON011 combination is therefore relevant to industrial facilities that need to monitor rotating machinery, support predictive maintenance, and identify mechanical changes before they develop into more serious equipment problems.

Technical Specifications

Note: Specifications depend on the exact PR6424 probe configuration, cable arrangement, converter variant, and measurement range. Confirm the full model suffix and supplied accessories before installation.

Function and Working Principle

The PR6424/01+CON011 uses the eddy current measurement principle to detect changes in the distance between a sensor tip and a conductive metal target.

The sensor is positioned close to the rotating shaft. As the distance between the probe and the shaft changes, the electrical characteristics of the sensor circuit change. The signal converter processes these changes and provides an output that can be interpreted by a compatible machinery monitoring system.

1. Non-Contact Displacement Measurement

The PR6424 sensor measures shaft movement without touching the rotating surface. This is particularly important in high-speed machinery, where physical contact between a sensor and the shaft would be impractical.

The sensor continuously detects changes in the gap between its sensing head and the target surface. These changes can represent shaft displacement, vibration, or position variation.

Non-contact measurement helps avoid mechanical wear at the sensing point and allows continuous monitoring during normal machine operation.

2. Eddy Current Measurement Principle

The sensor generates an electromagnetic field near its sensing tip. When a conductive target enters this field, eddy currents are induced in the target material.

The induced currents affect the electrical characteristics of the sensor. The resulting signal varies according to the distance between the sensor and the target.

The CON011 converter conditions the sensor signal so that the measurement can be used by a compatible monitoring system.

For reliable results, the target material must meet the sensor’s requirements. The PR6424 specification identifies ferromagnetic steel, with 42CrMo4 as a standard target material.

3. Shaft Vibration Monitoring

Rotating shafts may move because of imbalance, misalignment, bearing problems, mechanical looseness, or changing operating loads.

The PR6424 can detect dynamic changes in the shaft-to-probe gap. These measurements can be used to evaluate shaft vibration and identify changes in machine behavior.

Monitoring personnel can compare measured vibration levels with established operating limits and historical trends.

4. Shaft Position Measurement

The sensor can also measure static displacement within its configured measuring range. This is useful for monitoring shaft position and detecting changes in the mechanical relationship between rotating and stationary components.

In turbine applications, shaft position information can contribute to monitoring thrust movement and other mechanical conditions, depending on the sensor arrangement.

5. Signal Conversion and Output

The CON011 is designed to work with compatible EPRO PR6424 sensor configurations. It conditions the measurement signal and makes it available to the associated monitoring equipment.

The converter must be selected according to the probe type and required measurement range. Different converter configurations may support different standard or extended measurement ranges.

For this reason, the exact converter part number and probe configuration should be checked before replacing or mixing components.

Role in Industrial Machinery Monitoring Systems

The PR6424/01+CON011 can serve as a sensing element in a machinery condition monitoring system. It provides measurement information that can be used by protection monitors, diagnostic systems, and industrial control equipment.

1. Integration with Machinery Protection Systems

Critical rotating machinery often uses dedicated monitoring equipment to measure shaft vibration and position. The sensor and converter provide the measurement signal required by compatible monitoring channels.

Depending on the installed architecture, the resulting data can be used for alarm generation, equipment protection, and maintenance analysis.

The sensor itself does not replace the machinery protection monitor. It forms part of a larger measurement and protection chain.

2. Integration with DCS Platforms

A distributed control system can receive machinery status information through compatible monitoring hardware or communication interfaces.

This allows operators to view important equipment conditions alongside process variables such as pressure, temperature, flow, and speed.

For example, a turbine operator may review shaft vibration information together with steam pressure and operating load to understand changes in equipment behavior.

3. PLC and Control System Coordination

In suitable installations, monitoring information can be transferred to a PLC-based control system through compatible signal interfaces or monitoring modules.

The PLC can use available status signals to coordinate alarms, operating sequences, and equipment interlocks.

The exact interface depends on the monitoring hardware and the electrical output configuration. The PR6424/01+CON011 should not be assumed to connect directly to every PLC input without suitable signal conditioning and interface equipment.

4. Predictive Maintenance

Continuous shaft measurement provides information that maintenance teams can use to evaluate changes over time.

A gradual increase in vibration, an unusual displacement pattern, or a sudden change in shaft position may indicate that further inspection is required.

Trend analysis can help maintenance personnel plan inspections and repairs based on actual equipment conditions rather than relying exclusively on fixed maintenance intervals.

Industrial Applications

The EPRO PR6424/01+CON011 is intended for applications involving rotating machinery that requires non-contact shaft displacement and vibration measurement.

1. Steam Turbines

Steam turbines operate under demanding mechanical and thermal conditions. Shaft vibration and displacement monitoring are important for evaluating rotor behavior and supporting machinery protection.

The PR6424 can be installed at suitable measurement positions to detect changes in shaft movement. The resulting data can contribute to monitoring rotor vibration, shaft position, and other mechanical conditions.

Correct probe positioning and target preparation are essential for reliable measurement.

2. Gas Turbines

Gas turbines operate at high rotational speeds and require continuous monitoring of critical mechanical components.

Eddy current sensors can provide shaft displacement information without contacting the rotating surface. When connected to an appropriate monitoring system, the measurements can help identify abnormal vibration and mechanical changes.

3. Industrial Compressors

Large compressors are used in petrochemical plants, gas processing facilities, refineries, and other industrial installations.

Changes in shaft vibration may be associated with rotor imbalance, bearing deterioration, misalignment, or other mechanical conditions.

The PR6424 measurement system can provide continuous shaft-related information for machinery monitoring and maintenance assessment.

4. Industrial Pumps

Large process pumps often operate continuously and may be exposed to changing hydraulic and mechanical loads.

Shaft displacement monitoring can help maintenance teams identify abnormal movement and evaluate changes in rotating equipment behavior.

The sensor can be used in suitable pump monitoring arrangements where its measurement range and installation requirements match the application.

5. Industrial Fans

Large fans used in power generation, steel production, and process industries may require continuous vibration monitoring.

A non-contact eddy current sensor can measure shaft movement and provide information for evaluating rotor behavior.

For each installation, the shaft material, diameter, sensor mounting position, and operating conditions should be checked against the sensor specifications.

Installation and System Integration

Correct installation is essential for accurate measurement and stable long-term operation.

1. Verify the Complete Sensor Configuration

Before installation, confirm the PR6424 probe model, CON011 converter variant, cable length, connector type, and required measurement range.

The PR6424 series includes different mechanical and cable configurations. A sensor with the same 16 mm head diameter may not have identical mounting dimensions or electrical characteristics.

Do not assume that every PR6424 probe can be paired with every converter configuration without checking the manufacturer’s compatibility information.

2. Select the Correct Mounting Position

The sensor should be installed at a suitable location near the rotating shaft. The mounting arrangement must provide sufficient mechanical stability and maintain the specified measurement gap.

Avoid mounting positions that expose the sensor cable to excessive vibration, heat, or mechanical interference.

The installation should also allow access for inspection, adjustment, and replacement.

3. Set the Initial Air Gap

The initial gap between the sensor tip and target surface is important for measurement accuracy.

The PR6424 specification identifies an approximate nominal center air gap of 2.7 mm. The actual setting must follow the relevant probe and converter documentation.

Incorrect initial gap adjustment may cause the measurement to operate outside its linear range, resulting in inaccurate readings or unstable monitoring signals.

4. Check Target Material and Surface Condition

The sensor is designed for use with a suitable conductive target. Ferromagnetic steel is identified as the standard target material in the PR6424 specifications.

The shaft surface should be suitable for eddy current measurement. Excessive surface irregularities, unsuitable materials, or incorrect shaft dimensions can affect measurement performance.

5. Connect the CON011 Converter

Connect the sensor to the compatible CON011 converter using the specified cable and connector arrangement.

Keep sensor wiring away from sources of strong electrical interference where practical. Follow the manufacturer’s grounding and shielding requirements.

The converter should be mounted in an appropriate location with suitable environmental protection and access for maintenance.

6. Commission and Calibrate the Measurement Chain

After installation, verify the sensor gap, wiring, converter configuration, and monitoring channel settings.

Check the measurement output against the expected operating conditions and confirm that the monitoring equipment displays reasonable values.

Record the initial gap voltage and operating readings where required by the maintenance procedure. These baseline values can support future condition assessment.

Compatible System Components

A complete PR6424 measurement installation may include several components in addition to the probe and converter.

The components listed above are examples of a complete measurement system. They are not necessarily included in the PR6424/01+CON011 supply package.

Alternative Models and Replacement Considerations

The PR6424 belongs to the EPRO eddy current sensor family. When replacing the sensor or converter, the complete measurement configuration must be considered.

A replacement should be selected based on the following information:

• Full PR6424 probe part number.
• Sensor head diameter and mechanical dimensions.
• Thread type and probe body length.
• Cable length and connector type.
• Standard or extended measurement range.
• Converter model and configuration.
• Target shaft material and diameter.
• Monitoring system input requirements.
• Operating temperature and environmental conditions.

A probe with the same 16 mm sensing diameter is not necessarily a direct replacement. Differences in cable arrangement, mounting dimensions, converter configuration, and measuring range may affect system operation.

Key Advantages

Non-Contact Measurement

The PR6424 measures shaft movement without physical contact with the rotating target. This supports continuous measurement without introducing contact-related wear at the sensing point.

16 mm Sensing Head

The 16 mm sensor head is designed for suitable large-shaft machinery monitoring applications, including turbines, compressors, pumps, and fans.

Static and Dynamic Measurement

The sensor can measure both static displacement and dynamic shaft movement within its specified operating range.

High Measurement Sensitivity

The specified sensitivity of 4 V/mm supports measurement of relatively small changes in the sensor-to-target gap.

Industrial Temperature Capability

The PR6424 sensor is designed for demanding industrial environments, with a published operating temperature range of -35°C to +180°C. Installation limits for the cable and other components must also be observed.

Integration with Machinery Monitoring Equipment

When paired with a compatible converter and monitoring system, the sensor can contribute to machinery protection, vibration monitoring, and predictive maintenance strategies.

Support for Critical Rotating Equipment

The measurement principle and application design make the PR6424 suitable for selected critical rotating machinery where shaft displacement information is required.

Technical FAQs

1. What is the EPRO PR6424/01+CON011?

It is a 16 mm eddy current sensor system consisting of a PR6424 series probe and a CON011 signal converter. It is used for non-contact measurement of shaft displacement and vibration in rotating machinery.

2. What does the 16 mm specification mean?

The 16 mm value refers to the sensor head diameter. It identifies the sensing-head size rather than the overall length of the probe or cable.

3. What is the measuring sensitivity of the PR6424?

The published sensitivity is 4 V/mm, equivalent to approximately 101.6 mV/mil. The specified linearity is no more than ±1.5%.

4. What is the normal static measurement range?

The standard PR6424 specification identifies a static range of ±2.0 mm. Extended measuring ranges may be available through specific converter configurations.

5. What is the nominal air gap?

The published nominal center air gap is approximately 2.7 mm. The correct installation gap must be set according to the exact sensor and converter documentation.

6. What machinery can use this sensor?

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

7. Does the PR6424 contact the rotating shaft?

No. It uses the eddy current principle to measure the distance between the sensor tip and a conductive target without physical contact.

8. What is the function of the CON011?

The CON011 is a signal converter designed for compatible EPRO eddy current probes. It conditions the probe signal for use by a suitable monitoring system.

9. Can the PR6424 connect directly to a PLC?

The sensor should be used with its compatible signal converter and an appropriate monitoring or input interface. Direct connection to a standard PLC input should not be assumed without verifying signal characteristics and interface requirements.

10. What should be checked before replacing the sensor?

Check the complete probe model, thread, body length, cable configuration, connector, converter model, measuring range, target material, and monitoring-system compatibility.

Procurement and Maintenance Recommendations

When purchasing the EPRO PR6424/01+CON011, verify that the supplied probe and converter match the required measurement configuration. The complete part number is important because different PR6424 variants may have different cable lengths, mechanical dimensions, and connector arrangements.

For replacement projects, compare the existing sensor with the proposed unit before installation. Confirm the required mounting thread, probe length, initial gap, converter compatibility, and monitoring channel settings.

For used or refurbished equipment, request photographs of the probe identification, cable, connectors, and converter label. Check for damaged insulation, bent connectors, corrosion, or physical damage to the sensing head.

During routine maintenance, inspect the probe mounting, cable routing, connectors, and converter terminals. Monitor the measurement trend and investigate sudden changes or readings that move outside the expected operating range.

Keep a record of the initial gap setting, baseline measurement values, converter configuration, and installation location. This information can help maintenance teams identify changes in sensor performance and simplify future replacement work.

Conclusion

The EPRO PR6424/01+CON011 16 mm Eddy Current Sensor is designed for non-contact measurement of shaft displacement and vibration in critical rotating machinery. Its 16 mm sensing head, 4 V/mm sensitivity, and compatibility with the CON011 signal converter make it a relevant component for selected turbine, compressor, pump, and fan monitoring applications.

By providing continuous measurement of shaft movement, the system can support machinery condition monitoring, equipment protection, and predictive maintenance. Correct probe selection, converter matching, initial air-gap adjustment, and integration with compatible monitoring equipment are essential for obtaining reliable measurement results.