Emerson EPRO PR6423/010-020 8mm Eddy Current Sensor

Product Overview

A precision non-contact sensor arrives as the PR6423/010-020 from Emerson EPRO. This 8mm eddy current sensor is designed for critical turbomachinery applications, so it handles demanding measurement tasks. The PR6423/010-020 measures radial and axial shaft dynamic displacement accurately, which makes it invaluable for machine protection. Engineers use this sensor for steam, gas, and hydro turbines worldwide, yet it also serves compressors and pumps. Consequently, the PR6423/010-020 suits gearboxes and fans with equal effectiveness. The sensor measures position, eccentricity, and speed of rotating shafts, so one device covers multiple parameters. Furthermore, the IP66 protection rating ensures reliable operation in wet and dusty environments, thereby reducing maintenance concerns.

Performance Specifications

The PR6423/010-020 delivers precise linear measurement over a well-defined range. Linear measurement range spans 2 mm (80 mils), which covers most turbomachinery displacement needs. Initial air gap requires 0.5 mm (20 mils) for proper sensor setup, so installation follows a standard procedure. Incremental Scale Factor (ISF) reaches 8 V/mm (203.2 mV/mil) ±5% typical, but this assumes proper target material. This scale factor applies at temperature range from 0 to 45°C (+32 to +113°F), whereas deviations may occur outside this band. Deviation from best fit straight line (DSL) stays within ±0.025 mm (±1 mil), which ensures excellent measurement accuracy. Similarly, this linearity specification applies at 0 to 45°C temperature range, so consistency is guaranteed.

Minimum shaft diameter required for proper measurement is 25 mm (0.79 inches), because smaller diameters cause curvature errors. Target material standard is ferromagnetic steel type 42CrMo4 (AISI/SAE 4140), although other materials work with recalibration. Other target materials are available upon request for special applications, so flexibility exists. Thus, the PR6423/010-020 adapts to various machinery shaft materials without difficulty.

Model Number Breakdown

The PR6423/010-020 model number follows a systematic breakdown structure that reveals all options. PR6423 identifies the base sensor series and family, while /01 indicates an 8mm tip diameter. The first 0 specifies a 25mm case thread length (Option A=0), and the second 0 indicates an adapter plug is included (Option B=0). The third digit 2 specifies 4.0 meter cable length (Option C=2), whereas other digits would indicate different lengths. Finally, the last 0 indicates Lemo cable end type (Option D=0), so the connector type is fixed. Thus, the PR6423/010-020 comes with armored cable and Lemo connector, which simplifies ordering.

Physical Specifications

Temperature Range

The PR6423/010-020 operates across an exceptionally wide temperature range, so it suits extreme environments. Sensor including cable operates from -35 to +180°C (-31 to 356°F), while the cable and connector manage -35 to +150°C. Thus, the PR6423/010-020 suits high-temperature turbine applications perfectly, since steam turbines generate significant heat. The PEEK sensor tip maintains integrity even at extreme temperatures, whereas standard plastics would fail. PTFE cable insulation resists degradation from continuous heat exposure, so long-term reliability is assured.

Hazardous Area Approvals

The PR6423/010-020 carries multiple hazardous area certifications for safety, which expands its application range. Intrinsic Safety (ia) approvals include ATEX, IEC-Ex, and CSA certifications, but area classification depends on the converter. Sensor temperature classification varies with maximum ambient temperature (Ta), so choose the correct rating for your site. For T6 classification, Ta must stay ≤ 64°C for safety compliance, whereas T4 allows Ta ≤ 114°C. For T3 classification, Ta reaches up to 160°C maximum, which covers most industrial applications.

Non-sparking (nA) approvals also include ATEX, IEC-Ex, and CSA certifications, and area classification again depends on the converter. Temperature classifications follow the same limits as intrinsic safety versions, so the same rules apply. Thus, the PR6423/010-020 suits hazardous area installations globally, provided you use an approved converter.

Compliance and Certifications

The PR6423/010-020 meets multiple international compliance standards, so global acceptance is straightforward. CE certifications include 2014/30/EU (EMC Directive) under EN 61326-1, while additional directives cover ATEX and RoHS. ATEX compliance follows EN 60079-0 and EN 60079-11 standards, which are recognized throughout Europe. IEC-Ex compliance follows IEC 60079-0, IEC 60079-11, and IEC 60079-26, so international projects stay compliant.

CSA compliance covers multiple standards for North American installations, therefore the sensor works in Canada and the USA. These include CAN/CSA-C22.2 NO. 0-M91, NO. 157-92, and NO. 213-M1987, as well as CAN/CSA-E60079-15-02 (R2006). Finally, CAN/CSA-C22.2 NO. 61010-1-04 applies for measurement equipment safety, so complete coverage is achieved.

UL compliance includes ANSI/UL Standard 913-2004 for intrinsic safety, and ANSI/UL Standard 1604-1995 for hazardous locations. Finally, UL 60079-15 (2002) and UL 61010-1 complete the certification package, thereby satisfying North American requirements.

Measurement Applications

The PR6423/010-020 serves multiple critical measurement functions on turbomachinery, so one sensor type covers many needs. Radial shaft vibration monitoring detects imbalance and misalignment issues early, while axial position measurement monitors thrust bearing wear. Shaft eccentricity measurement helps during startup and slow-roll conditions, and speed measurement provides overspeed protection. Thus, the PR6423/010-020 provides comprehensive machinery protection, which reduces unplanned downtime.

Non-contact measurement eliminates wear on both sensor and target surface, so maintenance costs stay low over time. Eddy current principle works with ferromagnetic and non-ferromagnetic target materials, although sensitivity may vary. The sensor generates a high-frequency magnetic field for detection, yet it consumes very little power. Consequently, the PR6423/010-020 requires no physical contact with rotating shafts, which eliminates friction and wear completely.

Installation Guide

Follow these steps to install the PR6423/010-020 correctly.

1. Prepare Mounting Hole: Tap an M10x1 threaded hole in the sensor holder first.

2. Clean the Area: Remove all debris and metal shavings from the mounting area.

3. Set Initial Gap: Position the sensor tip 0.5 mm from the target surface carefully.

4. Tighten Lock Nut: Secure the PR6423/010-020 firmly in the holder, but avoid over-tightening.

5. Connect Cable: Attach the Lemo connector to the extension cable, then verify it locks.

6. Route Cable Safely: Keep sensor cable away from high-voltage power lines, or noise may occur.

7. Connect to Converter: Wire the sensor to an approved PR6423 converter, since compatibility matters.

8. Verify Air Gap: Check the initial air gap using a non-metallic feeler gauge, as metal tools affect readings.

9. Test Output: Apply power and verify linear output voltage response, then document the results.

Important: Never exceed the linear measurement range of 2 mm for accurate readings, or linearity will suffer. Always maintain the initial air gap of 0.50 mm for proper sensor biasing, since deviation affects scale factor. The sensor tip is fragile, so avoid physical contact with the sensitive area during handling. Finally, use only approved converters for hazardous area installations, because safety certifications depend on the complete system.

Key Features and Benefits

• Non-Contact Measurement: Eliminates wear and maintenance on both sensor and target, so lifecycle costs decrease.

• Wide Temperature Range: Operates from -35°C to +180°C for turbine applications, yet the connector handles -35 to +150°C.

• Hazardous Area Approvals: Includes ATEX, IEC-Ex, CSA, and UL certifications, thereby enabling global installation.

• High Linearity: DSL stays within ±0.025 mm for accurate measurements, which meets API standards.

• IP66 Protection: Resists dust ingress and powerful water jets, so outdoor installation is possible.

• 4.0 Meter Cable: Provides installation flexibility for remote mounting locations, as longer runs are accommodated.

The PR6423/010-020 delivers reliable non-contact measurements for critical machinery, so it is a trusted choice worldwide. Consequently, this sensor suits steam, gas, and hydro turbines, as well as compressors and pumps. Its linearity of ±0.025 mm ensures accurate displacement readings, while the sensitivity of 8 V/mm provides strong signals. Environmental tolerance includes IP66 protection and temperatures from -35 to +180°C, which covers most industrial requirements.

Package Contents

• One PR6423/010-020 eddy current sensor with 4.0m armored cable

• One Lemo connector (installed on cable end)

• One installation instruction sheet

Frequently Asked Questions (FAQ)

1. What is the difference between PR6423/010-000 and PR6423/010-020?

The PR6423/010-020 features a 4.0 meter cable length (Option C=2), whereas the PR6423/010-000 comes with a 1.0 meter cable. Both sensors share identical performance specifications and tip dimensions, so choose based on your cable length needs.

2. What is the linear measurement range of the PR6423/010-020?

The PR6423/010-020 offers a linear measurement range of 2 mm (80 mils), and the initial air gap should be 0.5 mm. Therefore, the total working range extends from 0.5 to 2.5 mm from the target, which suits most turbomachinery.

3. Can the PR6423/010-020 be used in hazardous areas?

Yes, the PR6423/010-020 carries ATEX, IEC-Ex, and CSA hazardous area approvals, so it suits explosive atmospheres. However, the area classification depends on the converter used with this sensor, so consult both datasheets.

4. What is the minimum shaft diameter for this sensor?

The PR6423/010-020 requires a minimum shaft diameter of 25 mm (0.79 inches), because smaller diameters cause measurement errors. Thus, always verify shaft diameter before selecting this sensor model, or accuracy may suffer.

5. What is the protection class of the PR6423/010-020?

The PR6423/010-020 carries an IP66 protection class per IEC 60529, which means complete dust protection. It also protects against powerful water jets from any direction, so outdoor and wash-down environments are suitable. Therefore, the sensor suits demanding industrial locations reliably.