PR6424/000-030+CON021 – Industrial-Grade 16mm Eddy Current Displacement System

When critical turbomachinery demands precision shaft monitoring under extreme conditions, the PR6424/000-030 paired with CON021 converter delivers uncompromising measurement accuracy. This factory-calibrated displacement monitoring solution combines a rugged 16mm eddy current proximity sensor with high-bandwidth signal conditioning, engineered specifically for large-diameter rotating equipment in power generation, petrochemical processing, and heavy industrial applications where downtime costs thousands per minute.

Designed for shafts 80mm and larger, this system provides continuous non-contact measurement of radial vibration, axial position, and thermal expansion in steam turbines, gas turbines, generators, and centrifugal compressors. The robust stainless steel construction withstands temperatures to 150°C while maintaining API 670 compliance for machinery protection systems.

Unlike generic 8mm sensors limited to smaller equipment, the 16mm electromagnetic coil generates sufficient field strength for stable measurements on large industrial shafts, while the CON021's DC-20kHz bandwidth captures both slow thermal drift and high-frequency vibration signatures critical for predictive maintenance programs.

Core Capabilities & Performance Advantages

→ Extended Measurement Range for Large Equipment
The 16mm sensor head provides ±2.0mm (±79 mils) static range to track shaft position during thermal transients, combined with 0-1000μm dynamic range for vibration amplitude measurement. This dual-range capability enables simultaneous monitoring of slow thermal growth and fast vibration events without range switching.

→ High-Resolution 4V/mm Output Sensitivity
Delivers 101.6 mV/mil scale factor with ±1.5% linearity across the full measurement span. This high voltage output improves signal-to-noise ratio in electrically noisy industrial environments, reducing false alarms in machinery protection systems while enabling detection of micro-level bearing wear patterns.

→ Wide-Bandwidth Signal Conditioning (DC to 20kHz)
The CON021 converter's frequency response captures DC position changes through 20,000 Hz vibration components, with rise time under 15 microseconds. This bandwidth exceeds API 670 requirements and enables analysis of twice-line-frequency electrical faults, gear mesh frequencies, and blade-pass vibration in turbomachinery.

→ Extreme Temperature & Pressure Tolerance
Operates continuously from -35°C to +150°C (-31°F to +302°F) with less than 4% error per 100°K temperature change. Withstands 10,000 hPa (145 psi) pressure at the sensor head and 5g vibration at 60 Hz, meeting the harsh environmental demands of steam turbine bearing housings and pressurized compressor casings.

✓ Factory-Matched System Calibration
Each sensor-converter pair ships with NIST-traceable calibration documentation verifying the 4V/mm scale factor and linearity specification. This eliminates field calibration requirements and ensures measurement accuracy for regulatory compliance and insurance inspections.

✓ Long-Term Measurement Stability
Less than 0.3% drift specification maintains calibration accuracy over years of continuous operation, reducing recalibration frequency and maintenance costs in 24/7 power generation facilities.

Industrial Application Solutions

Power Generation – Steam Turbine Vibration Monitoring

In utility-scale power plants, install XY probe pairs at each journal bearing on 200-400mm diameter turbine shafts. The 16mm sensor's electromagnetic field strength penetrates deep into large ferromagnetic shafts, providing stable gap voltage even with surface irregularities from years of operation. Monitor shaft orbit patterns to detect unbalance, misalignment, bearing wear, and fluid-induced instabilities like steam whirl before they escalate to catastrophic failures that could take the unit offline for weeks.

Oil & Gas – Centrifugal Compressor Thrust Protection

Protect multi-million dollar centrifugal compressors by monitoring axial shaft position with 16mm sensors mounted on thrust collars. The ±2mm static range accommodates normal thrust bearing float while detecting abnormal axial movement caused by bearing wear, process upsets, or surge conditions. Interface with emergency shutdown systems to trip the compressor before rotor-to-stator contact destroys internal components, preventing catastrophic failures that could cost $5-10 million in repairs and lost production.

Petrochemical – Gas Turbine Rotor Dynamics

In mechanical-drive gas turbines powering compressors and pumps, measure both radial vibration and differential expansion using 16mm sensors on 150-250mm diameter shafts. The system's 20kHz bandwidth captures high-frequency blade-pass vibration and combustion dynamics, while the DC response tracks thermal growth during startup sequences. Early detection of rotor rubs, bearing degradation, and blade damage prevents unplanned shutdowns in continuous process units where downtime disrupts entire production chains.

Manufacturing – Large Motor & Generator Monitoring

Monitor rotor eccentricity and vibration in synchronous motors and generators with shaft diameters exceeding 300mm. The 16mm sensor accommodates these large diameters while the CON021's bandwidth captures twice-line-frequency components (100/120 Hz) indicative of electrical unbalance, shorted rotor turns, or magnetic center misalignment. Detect developing electrical faults before they cause winding failures requiring months-long rewinds costing hundreds of thousands of dollars.

Marine Propulsion – Main Engine Shaft Monitoring

In large marine diesel engines and turbine propulsion systems, track crankshaft and propeller shaft position under the severe vibration and temperature conditions of engine rooms. The stainless steel construction resists saltwater corrosion while the 5g vibration tolerance withstands the harsh mechanical environment of ship propulsion machinery.

Technical Specifications & Selection Data

Shaft & Target Material Requirements

Critical selection criteria for proper system performance:

• Minimum shaft diameter: 80mm (3.15") – smaller shafts require 8mm or 5mm sensor variants
• Target material: Ferromagnetic steel (42CrMo4, 4140, or equivalent) – non-magnetic materials not compatible
• Surface finish: Clean, smooth steel free from chrome plating, nickel coating, or paint
• Maximum surface speed: 2,500 m/s (492,000 ft/min) for high-speed turbine applications
• Runout tolerance: Total indicated runout (TIR) should not exceed 50% of measurement range

Advanced Integration Features

Multi-Platform DCS & PLC Compatibility

The CON021's industry-standard -4V to -20V output interfaces directly with analog input modules from all major control system manufacturers. Connect to Rockwell ControlLogix 1756-IF16, Siemens S7-1500 SM1231, Emerson DeltaV, Honeywell Experion, ABB 800xA, or Yokogawa CENTUM systems without signal conditioning requirements. The negative-ground output convention matches legacy Bently Nevada proximitor systems, simplifying retrofits in existing machinery protection installations.

Machinery Protection System Integration

Deploy with Bently Nevada 3500/42M proximitor monitors, Emerson AMS 6500 machinery health monitors, or standalone vibration trip modules. The system's API 670 compliance ensures acceptance by insurance underwriters and regulatory authorities for critical machinery protection applications. Configure alarm and trip setpoints based on ISO 20816 or API 670 vibration limits, with typical alarm settings at 50-75% of trip values.

Sensor Family Interchangeability

The CON021 converter supports the complete Emerson EPRO eddy current sensor range, enabling standardization on a single converter platform while selecting sensor sizes matched to specific shaft diameters. Use PR6422 (5mm) for 15-40mm shafts, PR6423 (8mm) for 25-80mm shafts, PR6424 (16mm) for 80-200mm shafts, and PR6426 (25mm) for shafts exceeding 200mm diameter.

Installation & Commissioning Guidelines

Mechanical Mounting Best Practices

Install the sensor perpendicular to the shaft surface within ±5° angular tolerance using rigid mounting brackets that prevent movement under vibration and thermal expansion. Set the initial air gap to 2.7mm (106 mils) nominal center point using precision feeler gauges or micrometer stands. Ensure the mounting bracket provides sufficient adjustment range to accommodate shaft runout, thermal growth, and vibration amplitudes without the sensor bottoming out or losing signal.

The M18x1.5 metric threading provides secure installation in heavy-duty brackets designed for large turbomachinery. Torque the sensor to manufacturer specifications (typically 20-25 Nm) to prevent loosening under vibration while avoiding overtightening that could damage the stainless steel threads.

Electrical Installation & Grounding

Route the 8-meter PTFE-insulated cable from the sensor to the CON021 converter mounted in a climate-controlled cabinet. Avoid routing near high-voltage power cables, VFD wiring, or welding equipment that could induce electromagnetic interference. Use cable trays or flexible conduit for mechanical protection in high-traffic areas.

Connect the Lemo self-locking plug to the converter, ensuring the locking collar fully engages to prevent vibration-induced disconnection. Wire the -24VDC power supply and output signals to screw terminals, maintaining proper polarity. Ground the cable shield at the converter end only to prevent ground loops that could introduce noise into the measurement signal.

System Verification & Calibration Confirmation

Although the system ships factory-calibrated, field verification confirms measurement accuracy after installation. Use precision micrometer stands or calibrated gap gauges to verify the 4V/mm scale factor at three points: 1.7mm, 2.7mm, and 3.7mm gaps (±1mm from nominal center). Measure the output voltage at each gap and confirm linearity within the ±1.5% specification.

Document calibration results including ambient temperature, shaft material, and surface condition for machinery protection system commissioning records and regulatory compliance audits. Retain factory calibration certificates for insurance inspections and API 670 compliance verification.

Delivery, Warranty & Technical Support

Lead Time & Shipping: Standard configurations ship within 3-5 business days via express courier with protective packaging for industrial components. Custom cable lengths or special threading options may require 2-3 weeks for factory configuration. International shipments include all necessary export documentation and customs declarations.

Warranty Coverage: 24-month manufacturer warranty covers defects in materials and workmanship under normal industrial operating conditions. Warranty includes replacement of defective sensors or converters with advance exchange available to minimize downtime in critical applications.

Technical Documentation: Each system includes installation manual, calibration certificate, dimensional drawings, wiring diagrams, and API 670 compliance documentation. AutoCAD mounting drawings and 3D STEP models available for mechanical design integration.

Engineering Support: Our turbomachinery monitoring specialists provide application assistance for sensor selection, mounting design, system integration, and commissioning support. Contact our technical team for project-specific quotations, multi-unit pricing for power plant installations, and field service coordination.

Frequently Asked Questions

What shaft diameter range is compatible with the 16mm PR6424 sensor?

The PR6424 16mm sensor requires a minimum shaft diameter of 80mm (3.15 inches) for specified performance. For smaller shafts, use the PR6423 8mm sensor (25mm minimum diameter) or PR6422 5mm sensor (15mm minimum diameter). For shafts exceeding 200mm diameter, the PR6426 25mm sensor provides enhanced electromagnetic field strength.

Can this system monitor both radial vibration and axial position simultaneously?

A single sensor measures displacement in one axis only. For complete XY radial vibration monitoring, install two sensors 90° apart at each bearing location. For combined radial and axial monitoring, add a third sensor oriented axially toward a thrust collar or shaft shoulder. Each sensor requires a dedicated CON021 converter.

How does the 16mm sensor compare to Bently Nevada 3300 XL 11mm probes?

The PR6424 16mm sensor provides similar functionality to Bently Nevada 3300 XL 11mm probes but with larger electromagnetic coil diameter for improved performance on shafts exceeding 100mm diameter. The 4V/mm sensitivity matches the 200 mV/mil scale factor of Bently probes when accounting for unit conversion. The CON021 converter output is compatible with Bently 3500 rack monitors.

What is the recommended calibration interval for continuous operation?

With less than 0.3% long-term drift specification, annual calibration verification is typically sufficient for most industrial applications. Critical machinery protection systems subject to regulatory oversight may require semi-annual or quarterly verification depending on jurisdiction and insurance requirements. The factory calibration remains valid for the sensor's operational lifetime under normal conditions.

Can the CON021 converter power multiple sensors simultaneously?

No, each CON021 converter powers and conditions one sensor only. For multi-probe installations (XY pairs, axial position, differential expansion), specify one converter per sensor. Multi-channel rack-mount systems like the Emerson AMS 6500 can consolidate multiple channels in a single chassis for large installations.

Is the system suitable for hazardous area installations (ATEX/IECEx)?

The standard PR6424/000-030+CON021 configuration is not intrinsically safe certified. For hazardous area applications requiring ATEX or IECEx certification, specify the PR6424/00x-xxx-IS intrinsically safe variant with appropriate Zener barriers or galvanic isolators. Contact our application engineers for hazardous area system design assistance.

Order Your PR6424/000-030+CON021 System Today

Protect your critical turbomachinery investment with proven eddy current displacement monitoring technology trusted in power plants, refineries, and heavy industrial facilities worldwide. Our global logistics network ensures rapid delivery to your facility with complete technical documentation and engineering support.

Ready to specify your machinery protection system? Contact our turbomachinery specialists for detailed technical datasheets, application-specific recommendations, volume project pricing, and commissioning support. We provide complete turnkey solutions from sensor selection through field startup assistance.

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