Emerson PR6423 Eddy Current Sensor Modules: PR6423/01R-111 CON031

Technical Dossier

Product Details And Specifications

Emerson PR6423 Series: Comprehensive Module Range and Technical Overview

The Emerson (formerly Bently Nevada) PR6423 series represents one of the most widely deployed eddy current proximity sensor families in global heavy industry. Installed across petrochemical refineries, nuclear power stations, offshore platforms, and large-scale rotating machinery facilities, the PR6423 transducer system provides non-contact displacement and vibration measurement for shaft monitoring, axial position, and radial vibration applications. Its compatibility with the 3300 and 3500 series monitoring systems has made it a de facto standard in continuous machinery protection programs worldwide. The series operates on the eddy current principle: a high-frequency oscillating signal is applied to a probe coil, and the resulting change in impedance caused by proximity to a conductive target is converted into a linear DC voltage output. This output is then processed by a paired extension cable and proximitor/driver to deliver a calibrated signal to the monitoring rack.

The Evolution of PR6423 Architecture

The PR6423 series was developed as part of Bently Nevada's third-generation proximity transducer program, succeeding the earlier 7200 and 3300 XL probe families. The architecture is defined by a three-component system: the probe (PR6423/XXX), the extension cable (CON021/CON031/CON041), and the proximitor driver (CON011/CON021). Early variants used a fixed 5-meter cable system with limited temperature ratings. Subsequent revisions introduced high-temperature variants rated to 177°C for turbine bearing housings, and intrinsically safe (IS) versions certified for Zone 0/1 hazardous areas under ATEX and IECEx standards. The /01R, /02R, /03R, and /05R probe body designations indicate probe tip diameter and thread configuration, directly affecting the gap voltage calibration curve. The CON031 extension cable is the standard 5-meter interconnect used with the /01R probe body in the majority of general-purpose installations. As Emerson absorbed Bently Nevada, the part numbering convention was retained, but firmware and calibration data became integrated into the System 1 software ecosystem. Legacy installations using standalone rack monitors (3300 series) remain fully supported through the PR6423 hardware, making long-term spares availability a critical operational requirement for asset managers.

PR6423 Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly deployed configurations within the PR6423 eddy current transducer family. Units are classified by function within the three-component transducer system.

Proximity Probes (Sensor Heads)

• PR6423/001-010: 5mm probe, 1m integral cable, standard temperature, general-purpose radial vibration measurement.
• PR6423/01R-111: 8mm probe body, reverse-mount thread, standard temperature, paired with CON031 extension cable for shaft displacement monitoring.
• PR6423/002-030: 5mm probe, 3m integral cable, extended reach for deep bearing housing installations.
• PR6423/003-030: 8mm probe, 3m integral cable, high-sensitivity axial position measurement on thrust bearings.
• PR6423/004-030: 11mm probe, 3m integral cable, large-diameter shaft applications requiring extended measurement range.
• PR6423/005-030: 5mm probe, high-temperature variant rated to 177°C, steam turbine bearing applications.
• PR6423/007-030: 8mm probe, high-temperature, ATEX Zone 1 certified, petrochemical compressor trains.
• PR6423/008-030: 11mm probe, high-temperature, extended range, heavy-duty gas turbine installations.
• PR6423/010-030: 5mm probe, intrinsically safe (IS), IECEx certified, offshore platform applications.
• PR6423/012-030: 8mm probe, IS-rated, dual certification ATEX/IECEx, refinery critical machinery.

Extension Cables

• CON021: Standard 5m extension cable, compatible with 5mm and 8mm probe bodies, general-purpose installations.
• CON031: Standard 5m extension cable, primary pairing for PR6423/01R-111, most common field configuration.
• CON041: 9m extension cable, used where probe-to-proximitor distance exceeds standard 5m system length.
• CON051: High-temperature rated extension cable, required for pairings with /005 and /007 high-temp probe variants.

Proximitor Drivers / Signal Conditioners

• CON011: Standard proximitor driver, -24 VDC supply, 200 mV/mil output scale factor, rack-mount compatible with 3300 series.
• CON021-A10: Enhanced proximitor, field-configurable scale factor, compatible with 3500/42M proximity monitor module.

Sourcing Hard-to-Find & Obsolete PR6423 Parts

The PR6423 series has entered the mature-to-declining phase of its product lifecycle. Emerson has progressively migrated new installations toward the 3300 XL and Velomitor CT sensor platforms, and several PR6423 sub-variants have been formally discontinued. However, the installed base across operating refineries, power generation facilities, and chemical plants remains substantial, and replacement demand for maintenance, repair, and overhaul (MRO) programs continues at high volume.

DriveKNMS maintains a dedicated inventory program for PR6423 series components, including discontinued probe bodies, extension cables, and proximitor drivers. Our sourcing network covers factory-surplus, tested-used, and new-old-stock (NOS) units. For asset managers operating machinery protection systems with 10–25 year remaining service life, we provide long-term supply agreements and consignment stocking options. All sourced units are verified against Emerson's original calibration specifications prior to dispatch.

Quality Control for the PR6423 Range

The PR6423 transducer system requires system-level validation rather than component-level testing alone. DriveKNMS applies the following protocol to all PR6423 units processed through our facility:

• Impedance verification: Probe coil impedance is measured at 1 MHz to confirm coil integrity and detect winding degradation.
• Gap voltage calibration check: Each probe is bench-tested against a certified conductive target at defined gap distances (0.25mm to 2.5mm) to verify the output voltage curve matches the published scale factor (200 mV/mil or 7.87 V/mm).
• Cable continuity and insulation resistance: Extension cables are tested for conductor continuity, shield integrity, and insulation resistance (>100 MΩ at 500 VDC).
• System-level functional test: Probe, extension cable, and proximitor are tested as a matched set using a calibrated oscillator and target fixture to confirm end-to-end output linearity.
• Environmental inspection: Probe tip, connector bodies, and cable jacketing are inspected for mechanical damage, corrosion, and seal integrity.

All test records are retained and available upon request with each shipment.