EPRO PR6424 Modules | PR6424/010-000 CON021 Eddy Current Sensor

Technical Dossier

Product Details And Specifications

EPRO PR6424 Series: Comprehensive Module Range and Technical Overview

The EPRO PR6424 series is a family of eddy current proximity sensors engineered for continuous, non-contact displacement and vibration measurement in heavy industrial environments. Deployed extensively in chemical processing plants, nuclear power stations, oil refineries, and rotating machinery protection systems, the PR6424 series forms a core sensing layer within machinery protection systems (MPS) compliant with API 670 standards. These sensors operate in conjunction with EPRO signal conditioning units (CON0xx series) to deliver calibrated output signals to monitoring systems such as the EPRO MMS 6000 and Bently Nevada 3500 series. The PR6424 range is manufactured to IEC and ATEX standards, making it suitable for hazardous area classification zones. Its long-term installed base across global heavy industry means demand for spare parts, replacements, and lifecycle extension support remains high well into the 2020s.

The Evolution of PR6424 Architecture

The PR6424 series was developed by EPRO GmbH (later acquired by Emerson as part of the machinery health monitoring portfolio) as a standardized eddy current sensor platform. Early variants were designed for fixed-gap measurement with analog 4–20 mA or voltage outputs, paired with dedicated extension cables and driver/conditioner units. The architecture separates the sensing probe (PR6424) from the signal conditioning electronics (CON0xx), allowing field replacement of either component independently — a design philosophy that significantly reduces maintenance downtime in continuous-process industries.

Over successive generations, the series expanded to cover a range of probe tip diameters (5 mm, 8 mm, 11 mm), cable lengths (from 1 m to 9 m standard, with extension options), and temperature ratings. The CON021 conditioner introduced in this listing represents a mid-range signal conditioning unit compatible with the standard PR6424 probe body. Compatibility between probe and conditioner is determined by the system gap voltage calibration curve; mismatched combinations will produce non-linear output and must be avoided. As the broader EPRO product line has transitioned toward integration with Emerson AMS and CSI platforms, the PR6424 hardware itself has entered a mature/end-of-active-production phase, though Emerson continues to provide repair and limited new-unit supply. Third-party and aftermarket sourcing has become the primary channel for rapid spare parts fulfillment.

PR6424 Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly deployed models within the EPRO PR6424 eddy current sensor ecosystem. Each unit is classified by function and probe/conditioner specification.

Eddy Current Probes — 5 mm Tip Diameter

• PR6424/000-000: 5 mm probe, 1 m integral cable, standard temperature, no connector
• PR6424/001-000: 5 mm probe, 1 m integral cable, with M12 connector termination
• PR6424/002-000: 5 mm probe, 2 m integral cable, standard configuration
• PR6424/003-000: 5 mm probe, 3 m integral cable, standard configuration

Eddy Current Probes — 8 mm Tip Diameter

• PR6424/010-000: 8 mm probe body, 1 m integral cable, standard temperature rating, bare end termination — the probe component paired with CON021 in this listing
• PR6424/011-000: 8 mm probe, 1 m cable, M12 connector
• PR6424/012-000: 8 mm probe, 2 m integral cable
• PR6424/013-000: 8 mm probe, 3 m integral cable
• PR6424/014-000: 8 mm probe, 4 m integral cable
• PR6424/016-000: 8 mm probe, 6 m integral cable, extended reach configuration
• PR6424/019-000: 8 mm probe, 9 m integral cable, maximum standard length

Eddy Current Probes — 11 mm Tip Diameter

• PR6424/020-000: 11 mm probe, 1 m integral cable, high-sensitivity configuration for large shaft diameters
• PR6424/022-000: 11 mm probe, 2 m integral cable
• PR6424/023-000: 11 mm probe, 3 m integral cable

Signal Conditioners (CON Series) — Compatible with PR6424

• CON011: Standard signal conditioner, –24 VDC supply, 200 mV/mil output, DIN rail mount
• CON021: Enhanced signal conditioner, –24 VDC supply, 200 mV/mil output, panel mount, wider temperature range — paired with PR6424/010-000 in this listing
• CON031: High-temperature signal conditioner variant for elevated ambient environments
• CON041: Intrinsically safe conditioner, ATEX/IECEx certified, for Zone 1 hazardous areas

Sourcing Hard-to-Find & Obsolete PR6424 Parts

The PR6424 series has entered a mature production phase under Emerson's stewardship of the EPRO brand. New unit availability through standard distribution channels is inconsistent, with lead times frequently exceeding 16–24 weeks for certain probe/conditioner combinations. DriveKNMS maintains a dedicated inventory of PR6424 probes and CON0xx conditioners sourced from decommissioned plant equipment, authorized surplus channels, and verified aftermarket suppliers.

Quality Control for the PR6424 Range

Eddy current sensors present specific verification challenges due to the interdependency between probe geometry, cable length, and conditioner calibration. DriveKNMS applies the following test protocol to all PR6424 units prior to dispatch:

• Gap voltage linearity check: Each probe is tested against a calibrated steel target across the full measurement range (typically 0.25 mm to 2.5 mm for 8 mm probes) to verify output linearity within ±1% of the nominal calibration curve.
• Conditioner output verification: CON0xx units are powered at –24 VDC and output voltage is measured at defined gap increments to confirm sensitivity (mV/mil or mV/mm) matches the published specification.
• Cable continuity and insulation resistance: Integral cables are tested for conductor continuity and insulation resistance (>100 MΩ at 500 VDC) to detect any degradation from prior installation.
• Probe tip inspection: Physical inspection of the probe tip for mechanical damage, corrosion, or contamination that would affect the electromagnetic field geometry.
• Matched-pair validation: Where a probe and conditioner are sold as a system (as in PR6424/010-000 + CON021), the complete assembly is validated together to confirm system-level output accuracy.