EPRO PR6423 Modules PR6423/010-140 CON011

Technical Dossier

Product Details And Specifications

EPRO PR6423 Series Technical Notes

The EPRO PR6423 series is a family of eddy-current proximity transducers engineered for continuous, non-contact displacement and vibration measurement in rotating machinery. Manufactured by EPRO GmbH (a Woodward company), these sensors are installed across the global heavy-process industries — petrochemical refineries, nuclear power stations, offshore platforms, and large-scale compressor trains — where shaft displacement monitoring is a safety-critical function under API 670 and IEC 61511 standards.

The PR6423 series interfaces directly with EPRO's CON0xx signal conditioning modules and is fully compatible with the MMS 6000, MMS 3000, and legacy MMS 2000 machinery monitoring systems. Its 8 mm probe diameter and standardized M10 thread make it a direct mechanical replacement across multiple generations of EPRO hardware, reducing retrofit engineering time in brownfield installations.

The Evolution of PR6423 Architecture

The PR6423 lineage traces to EPRO's first-generation eddy-current probes developed in the 1980s for turbomachinery OEM integration. The original PR6422 series established the 5 mm probe standard; the PR6423 extended this to an 8 mm active tip, increasing linear measurement range and improving signal-to-noise ratio in high-temperature environments up to 177 °C.

Through the 1990s, EPRO standardized the CON0xx conditioner interface, decoupling probe sensitivity calibration from the signal conditioner. This allowed field replacement of probes without recalibration of the full channel — a significant operational advantage in continuous-process plants. The PR6423/010 through PR6423/060 sub-series cover cable lengths from 1 m to 9 m, with the three-digit suffix (e.g., -140) encoding the probe-to-conditioner cable assembly length in decimeters.

PR6423 Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly deployed configurations within the PR6423 eddy-current proximity transducer family. Each entry includes the associated signal conditioner where applicable.

Proximity Probes (Sensor Head)

• PR6423/001-000: 8 mm eddy-current probe, 1 m integral cable, no connector, bare-end termination.
• PR6423/002-000: 8 mm probe, 2 m integral cable, standard configuration for short-extension installations.
• PR6423/003-000: 8 mm probe, 3 m integral cable, general-purpose turbine bearing housing mount.
• PR6423/005-000: 8 mm probe, 5 m integral cable, mid-range extension for compressor pedestals.
• PR6423/007-000: 8 mm probe, 7 m integral cable, used where conditioner cabinets are remotely located.
• PR6423/010-000: 8 mm probe, 10 m integral cable, standard long-run configuration for large turbine halls.
• PR6423/010-140: 8 mm probe, 10 m integral cable, 14 m extension cable assembly; total system reach 24 m. Paired with CON011 conditioner.
• PR6423/010-180: 8 mm probe, 10 m integral cable, 18 m extension cable; total reach 28 m. Common in offshore module installations.
• PR6423/010-200: 8 mm probe, 10 m integral cable, 20 m extension cable; maximum standard reach configuration.
• PR6423/060-000: 8 mm probe, 6 m integral cable, compact installation variant for gearbox monitoring.

Signal Conditioners (CON Series — paired with PR6423)

• CON011: Standard DIN-rail signal conditioner for PR6423; outputs 4–20 mA and ±24 V DC buffered; the reference conditioner for PR6423/010-140 CON011.
• CON021: Dual-channel conditioner; monitors two PR6423 probes from a single module slot; used in X-Y shaft orbit measurement.
• CON031: Conditioner with HART communication overlay; enables digital diagnostics over the 4–20 mA loop without additional wiring.
• CON041: Intrinsically safe (ATEX Zone 0) conditioner variant; required for installations in explosive atmospheres (hydrogen-cooled generators, LNG compressors).
• CON051: High-temperature variant conditioner; rated for ambient temperatures up to 85 °C in conditioner cabinet; used in hot-section turbine monitoring.

Extension Cables & Accessories

• TQ-CON-PR6423: Factory-matched extension cable set, pre-trimmed and impedance-matched for PR6423 probe-conditioner systems.
• PR9268/200: Armored extension cable, 20 m, for high-vibration or rodent-risk environments.
• PR9376/010: Junction box for field-splicing PR6423 cable assemblies; IP67 rated.

Sourcing Hard-to-Find & Obsolete PR6423 Parts

For obsolete sub-variants (e.g., PR6423/001-000 with legacy BNC termination), DriveKNMS provides cross-reference engineering support to identify compatible modern equivalents or to source original units from global decommissioning projects.

Quality Control for the PR6423 Range

The PR6423 eddy-current probe system requires end-to-end electrical validation — probe, extension cable, and conditioner must be tested as a matched system, not as individual components. DriveKNMS applies the following test protocol to all PR6423 inventory:

• Static gap calibration: Each probe is mounted in a calibration fixture at 0.25 mm, 0.50 mm, 1.00 mm, and 1.50 mm air gaps. Output voltage linearity is verified against EPRO factory calibration curves (±1% tolerance).
• Cable continuity and insulation resistance: Center conductor, shield, and outer jacket are tested at 500 V DC. Insulation resistance must exceed 100 MΩ.
• Conditioner output verification: CON011 and CON0xx units are powered at nominal 24 V DC. Output current (4–20 mA) and buffered voltage (±24 V) are measured under simulated probe load.
• Thermal soak: Units destined for high-temperature applications are cycled from 25 °C to 85 °C and re-measured to confirm no drift beyond specification.
• Full system functional test: Probe + extension cable + conditioner are tested as an assembled channel. Gap-to-output transfer function is recorded and supplied with each shipment as a test certificate.