EPRO PR6423 Eddy Current Sensor Modules — PR6423/010-010-CN CON021

Technical Dossier

Product Details And Specifications

EPRO PR6423 Series: Comprehensive Module Range and Technical Overview

The EPRO PR6423 series is a family of eddy current displacement and proximity sensors manufactured by EPRO GmbH (now part of Baker Hughes / Bently Nevada ecosystem). These sensors are deployed globally in heavy industrial environments including petrochemical refineries, nuclear power stations, offshore platforms, and rotating machinery protection systems. The PR6423 series operates on the non-contact eddy current measurement principle, providing continuous shaft displacement, vibration, and position data to machinery protection systems (MPS) such as the EPRO MMS 6000 and compatible third-party DCS platforms.

In critical asset protection applications — gas turbines, steam turbines, compressors, and large pumps — the PR6423 sensor is paired with a CON021 or CON041 signal conditioner to form a complete measurement chain. This chain feeds 4–20 mA or voltage outputs to safety instrumented systems (SIS) and distributed control systems (DCS), making the PR6423 a foundational component in ISO 13373 and API 670 compliant installations.

The Evolution of PR6423 Architecture

The PR6423 series was introduced by EPRO GmbH as a successor to earlier inductive proximity sensor designs, addressing the need for higher temperature tolerance and improved EMI immunity in industrial rotating machinery environments. Early variants used a fixed cable assembly with a standard 5-meter or 9-meter extension cable terminated at a CON011 or CON021 conditioner. As plant automation standards evolved through the 1990s and 2000s, EPRO expanded the series to include variants with different probe tip diameters (8 mm standard, 11 mm extended range), cable lengths (1 m, 3 m, 5 m, 9 m), and connector types (CN = connector version, integral cable versions).

Following Baker Hughes' acquisition of EPRO, the PR6423 series entered a managed lifecycle phase. Many SKUs are now classified as Last-Time-Buy (LTB) or obsolete, with the Bently Nevada 3300 XL and 330100 series positioned as functional replacements in new installations. However, the installed base of PR6423 sensors in operating plants remains substantial, and direct replacement with Bently Nevada probes requires conditioner recalibration and, in some cases, system reconfiguration — making original PR6423 spare parts the preferred solution for maintenance teams.

PR6423 Full Catalog & Functionalities (SKU List)

The following SKUs represent the verified PR6423 series product range, classified by probe configuration, cable length, and conditioner pairing. Each entry reflects a distinct part number used in EPRO documentation and plant maintenance records.

PR6423/000-010-CN: 8 mm eddy current probe, 1 m integral cable, connector termination, standard range.
PR6423/000-030-CN: 8 mm probe, 3 m integral cable, connector termination, standard gap range.
PR6423/000-050-CN: 8 mm probe, 5 m integral cable, connector termination, standard installation.
PR6423/000-090-CN: 8 mm probe, 9 m integral cable, connector termination, long-run configuration.
PR6423/010-010-CN: 8 mm probe, 1 m cable, connector type, extended temperature rating.
PR6423/010-030-CN: 8 mm probe, 3 m cable, connector type, high-temp process environment.
PR6423/010-050-CN: 8 mm probe, 5 m cable, connector type, standard turbine application.
PR6423/010-090-CN: 8 mm probe, 9 m cable, connector type, remote conditioner installation.
PR6423/011-010-CN: 8 mm probe, 1 m cable, armored cable variant, vibration-prone mounting.
PR6423/011-030-CN: 8 mm probe, 3 m armored cable, connector termination, compressor duty.
PR6423/011-050-CN: 8 mm probe, 5 m armored cable, connector type, offshore platform use.
PR6423/011-090-CN: 8 mm probe, 9 m armored cable, connector type, extended reach installation.
PR6423/010-010-CN CON021: 8 mm probe + CON021 conditioner kit, 1 m cable, complete measurement chain, API 670 compliant — this listing.
PR6423/010-030-CN CON021: 8 mm probe + CON021 conditioner, 3 m cable, turbine shaft displacement kit.
PR6423/010-050-CN CON021: 8 mm probe + CON021 conditioner, 5 m cable, standard MPS integration kit.
PR6423/010-090-CN CON021: 8 mm probe + CON021 conditioner, 9 m cable, long-distance measurement chain.
PR6423/010-010-CN CON041: 8 mm probe + CON041 dual-channel conditioner, 1 m cable, redundant measurement.
PR6423/010-030-CN CON041: 8 mm probe + CON041 conditioner, 3 m cable, SIL-rated redundant loop.

Sourcing Hard-to-Find & Obsolete PR6423 Parts

DriveKNMS maintains a dedicated inventory program for EPRO PR6423 series components, including probe assemblies, extension cables, and CON021/CON041 signal conditioners. As the PR6423 series has entered its mature-to-end-of-life phase under Baker Hughes product management, OEM lead times for remaining active SKUs can exceed 16–26 weeks. For plants operating under planned maintenance windows of 4–8 weeks, this lead time is operationally unacceptable.

DriveKNMS sources PR6423 components through verified industrial surplus channels, decommissioned plant inventories, and authorized distributor networks. All units are inspected, tested, and documented prior to dispatch. For obsolete variants no longer available through OEM channels, DriveKNMS provides cross-reference analysis to identify compatible alternatives within the EPRO ecosystem or from Bently Nevada, Wilcoxon, and Metrix product lines — with full documentation of any calibration adjustments required.

Quality Control for the PR6423 Range

The PR6423 eddy current sensor system requires specialized test procedures that differ from standard passive sensor verification. DriveKNMS applies the following protocol to all PR6423 units processed through its facility:

Gap Calibration Verification: Each probe is tested against a calibrated target (AISI 4140 steel) at the nominal gap range (0.25 mm to 2.25 mm for standard 8 mm probes) using a precision micrometer stage. Output linearity is verified against the EPRO calibration curve for the specific conditioner pairing (CON021 or CON041).
Conditioner Output Test: CON021 and CON041 units are powered at rated supply voltage (18–30 VDC) and output signal (4–20 mA / 0–10 V) is measured across the full gap range. Frequency response is verified to 10 kHz minimum.
Cable Integrity Check: Extension cable shield continuity, insulation resistance (>100 MΩ at 500 VDC), and connector pin integrity are verified for all cable assemblies.
Temperature Soak Test: High-temperature variants are subjected to a 2-hour soak at rated operating temperature (up to 180°C for standard PR6423 probes) prior to final calibration check.
Documentation Package: Each unit ships with a test report, calibration data sheet, and traceability record.

For sourcing inquiries, cross-reference requests, or bulk orders for the EPRO PR6423 series: