Emerson Bently Nevada PR6423 Eddy Current Proximity Sensors: PR6423/004-030 CON021/913-030

Technical Dossier

Product Details And Specifications

Emerson Bently Nevada PR6423 Series: Comprehensive Module Range and Technical Overview

The Emerson Bently Nevada PR6423 series is a globally deployed eddy current proximity transducer system used in continuous vibration and position monitoring of rotating machinery. It is a standard component in critical asset protection programs at petrochemical plants, refineries, nuclear power stations, LNG terminals, and offshore platforms. The PR6423 sensor operates on the eddy current principle: a high-frequency oscillating magnetic field is generated at the probe tip; when a conductive target approaches, eddy currents are induced, reducing the oscillator amplitude in a manner proportional to the gap distance. This signal is conditioned by a paired CON021 extension cable and driver/oscillator to produce a DC voltage output compatible with Bently Nevada 3500 and ADRE monitoring systems. The series is manufactured to API 670 standards and is the predominant proximity probe specification written into machinery protection contracts across heavy industry worldwide.

The Evolution of PR6423 Architecture

The PR6423 series was developed under Bently Nevada Corporation prior to its acquisition by General Electric in 2002 and subsequent integration into Emerson's Automation Solutions portfolio. Early proximity probe systems used discrete oscillator-demodulator circuits with limited temperature compensation. The PR6423 generation introduced integrated tip geometry standardization, allowing interchangeability across installations without recalibration of the full loop, provided the extension cable and driver remain matched. The system architecture is a three-component loop: the PR6423 probe (sensor), the CON021 extension cable (signal transmission), and the CON011 or CON021/9xx driver/oscillator (signal conditioning). Each component carries its own part number suffix encoding tip diameter, cable length, and connector type. The PR6423 series is now in a mature/end-of-production lifecycle. Emerson's current replacement platform is the 3300 XL series and the 330100/330130 proximity transducer system. However, installed base density at legacy facilities means PR6423 components remain in active procurement globally, with replacement cycles driven by scheduled turnarounds rather than system upgrades. Long-term maintenance support, including new-old-stock (NOS) and recertified units, is the primary sourcing mode for this series.

PR6423 Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly procured configurations within the PR6423 proximity probe and CON021 extension cable system. Each entry reflects a specific combination of probe tip diameter, cable length, and connector specification.

PR6423/001-030: 5mm tip diameter probe, 1m armored cable, standard connector
PR6423/002-030: 5mm tip diameter probe, 2m armored cable, standard connector
PR6423/003-030: 5mm tip diameter probe, 3m armored cable, standard connector
PR6423/004-030: 5mm tip diameter probe, 4m armored cable, standard connector — paired in this listing with CON021/913-030
PR6423/005-030: 5mm tip diameter probe, 5m armored cable, standard connector
PR6423/007-030: 5mm tip diameter probe, 7m armored cable, standard connector
PR6423/010-030: 5mm tip diameter probe, 10m armored cable, standard connector
PR6423/001-000: 5mm tip diameter probe, 1m cable, bare-end termination
PR6423/004-000: 5mm tip diameter probe, 4m cable, bare-end termination
CON021/913-030: Extension cable assembly, 9m total system length, 3m driver cable, standard connector — the conduit between PR6423 probe and the 3500 monitor rack driver
CON021/916-030: Extension cable assembly, 9m total system length, 6m driver cable, standard connector
CON021/920-030: Extension cable assembly, 9m total system length, 10m driver cable, standard connector
CON021/925-030: Extension cable assembly, 9m total system length, 15m driver cable, standard connector
CON011/916-030: Earlier-generation extension cable, 9m system, 6m driver section, compatible with PR6423 in legacy installations
CON011/920-030: Earlier-generation extension cable, 9m system, 10m driver section, legacy compatible
PR6423/004-030 CON021/913-030: Complete matched loop assembly — 4m probe cable + 9m system extension, the configuration covered by this listing, total system gap range 0.25–2.54mm, output sensitivity –7.87 V/mm nominal

Sourcing Hard-to-Find & Obsolete PR6423 Parts

The PR6423 series has been discontinued from active Emerson Bently Nevada production. Procurement is now exclusively through authorized distributors, surplus inventory channels, and specialist MRO suppliers. DriveKNMS maintains dedicated stock of PR6423 probe assemblies and CON021 extension cables sourced from decommissioned plant inventories, OEM overstock, and controlled refurbishment programs. For facilities operating Bently Nevada 3500 racks with PR6423 loops, direct replacement with the 330100 series requires recalibration of the monitor channel and verification of gap voltage setpoints — a process that is not always feasible during a short turnaround window. DriveKNMS provides like-for-like PR6423 replacements to eliminate this recalibration requirement, supporting maintenance teams that need to restore machinery protection within a fixed outage schedule. All units are supplied with traceability documentation and, where applicable, original OEM packaging.

Quality Control for the PR6423 Range

Each PR6423 probe and CON021 cable assembly processed by DriveKNMS undergoes a defined verification protocol prior to dispatch. Probe tip coil resistance is measured and compared against OEM specification bands. The full three-component loop (probe + extension cable + driver) is assembled and powered using a calibrated Bently Nevada proximitor power supply. Gap voltage linearity is verified across the full measurement range using a certified target material (AISI 4140 steel) on a micrometer-controlled fixture. Output sensitivity (V/mm) is recorded and compared to the nominal –7.87 V/mm specification. Extension cable shield continuity and insulation resistance are tested to confirm signal integrity over the full cable length. Units that fall outside OEM tolerance bands are quarantined and not dispatched. Test records are retained and available upon request for quality-critical installations.