EPRO PR6423 Modules: PR6423/001-010-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 transducers manufactured by Emerson (formerly Bently Nevada / EPRO GmbH), engineered for non-contact displacement, vibration, and position measurement in rotating machinery. These sensors are deployed across the full spectrum of heavy industrial infrastructure: petrochemical refineries, nuclear power stations, offshore platforms, gas compression trains, and large-scale turbomachinery installations. The PR6423 series operates on the eddy current principle, requiring a paired driver/oscillator (typically the CON021 or CON011 series) to form a complete measurement chain. Its rugged stainless-steel construction and wide temperature tolerance make it the standard-of-record for shaft proximity measurement in API 670-compliant machinery protection systems worldwide.

The Evolution of PR6423 Architecture

The PR6423 lineage traces to EPRO GmbH's early eddy current sensor platforms developed in the 1980s for European turbomachinery OEMs. The original PR6423/001 and PR6423/002 variants established the 5mm and 8mm tip-diameter form factors that remain in production today. When Emerson acquired EPRO in 2007, the series was integrated into the Emerson machinery protection ecosystem alongside the CSI and AMS platforms, while maintaining full backward compatibility with legacy CON011 and CON021 driver electronics.

The architecture is defined by three interdependent components: the probe body (PR6423/xxx), the extension cable (TQ-series), and the driver/oscillator (CON021 or CON011). The CON021 driver introduced a standardized -24 VDC supply rail and a 4–20 mA output option, enabling direct integration with DCS analog input cards without signal conditioning intermediaries. Later variants introduced the /CN (cable-nose) and /GY (grey cable jacket) suffixes to address installation-specific requirements in high-temperature or chemically aggressive environments. The series is now in a mature/sustaining lifecycle phase; Emerson continues to supply replacement units, but no new architectural revisions are planned. Long-term maintenance support is the primary procurement driver for this series.

PR6423 Full Catalog & Functionalities (SKU List)

The following SKUs represent the verified, commonly stocked configurations within the PR6423 eddy current transducer family. Each entry reflects a distinct probe geometry, cable length, or connector specification.

PR6423/001-010-CN CON021: 5mm probe, 1m cable, cable-nose, with CON021 driver — standard shaft proximity measurement chain for API 670 systems.
PR6423/001-010-GY CON021: 5mm probe, 1m cable, grey jacket variant, CON021 driver — for chemically aggressive environments.
PR6423/001-030-CN CON021: 5mm probe, 3m extension cable, cable-nose, CON021 driver — extended reach installations.
PR6423/002-010-CN CON021: 8mm probe, 1m cable, cable-nose, CON021 driver — higher sensitivity for large-diameter shaft applications.
PR6423/002-030-CN CON021: 8mm probe, 3m cable, cable-nose, CON021 driver — standard long-reach 8mm configuration.
PR6423/002-050-CN CON021: 8mm probe, 5m cable, cable-nose, CON021 driver — for remote driver mounting configurations.
PR6423/003-010-CN CON021: 11mm probe, 1m cable, cable-nose, CON021 driver — heavy-duty shaft proximity for large turbines.
PR6423/003-030-CN CON021: 11mm probe, 3m cable, cable-nose, CON021 driver — extended 11mm probe chain.
PR6423/004-010-CN CON021: 14mm probe, 1m cable, cable-nose, CON021 driver — maximum sensitivity eddy current configuration.
PR6423/001-010-CN CON011: 5mm probe, 1m cable, cable-nose, legacy CON011 driver — direct replacement for pre-2007 EPRO installations.
PR6423/002-010-CN CON011: 8mm probe, 1m cable, cable-nose, CON011 driver — legacy 8mm chain for older Bently Nevada racks.
PR6423/001-030-GY CON021: 5mm probe, 3m grey-jacket cable, CON021 driver — offshore/marine environment specification.
PR6423/002-030-GY CON021: 8mm probe, 3m grey-jacket cable, CON021 driver — chemical plant corrosion-resistant variant.
PR6423/003-050-CN CON021: 11mm probe, 5m cable, cable-nose, CON021 driver — long-reach heavy turbine proximity chain.
PR6423/004-030-CN CON021: 14mm probe, 3m cable, cable-nose, CON021 driver — extended 14mm configuration for large shaft diameters.
PR6423/001-010-CN CON021-TQ: 5mm probe with TQ-series armored extension cable — for high-vibration mounting environments.

Sourcing Hard-to-Find & Obsolete PR6423 Parts

DriveKNMS maintains a dedicated inventory of PR6423 series transducers, including configurations that have been discontinued from Emerson's standard catalog. As the PR6423 series enters its long-term sustaining phase, procurement lead times from the OEM can extend to 16–26 weeks for non-standard cable lengths and connector variants. DriveKNMS sources verified surplus and refurbished PR6423 assemblies from decommissioned plant inventories, providing a critical supply channel for facilities operating legacy Bently Nevada 3300 and 7200 series racks that cannot be economically upgraded.

All sourced units are cross-referenced against the original EPRO part numbering matrix to confirm probe diameter, cable length, connector type, and driver compatibility before listing. CON011-compatible variants — increasingly difficult to source through standard distribution — are held in stock specifically to support facilities with no near-term plans to migrate to CON021-based architectures.

Quality Control for the PR6423 Range

Each PR6423 transducer processed by DriveKNMS undergoes a structured verification protocol designed around the specific measurement physics of eddy current proximity systems. Static gap calibration is performed using a certified non-ferrous target plate to verify the probe's linear output range (typically 0–2mm for 5mm probes, 0–4mm for 8mm probes). Driver oscillator frequency is confirmed at the CON021/CON011 interface to ensure the 1 MHz carrier signal is within the ±2% tolerance required for accurate gap-to-voltage conversion. Cable continuity and shield integrity are verified across the full probe-cable-driver chain to eliminate ground loop artifacts that would corrupt vibration readings in a live machinery protection rack. Units exhibiting tip damage, coil resistance drift exceeding ±5%, or connector corrosion are quarantined and not listed for resale.