EPRO PR6426/010-140 Eddy Current Sensor (Manual - No Diagram Version)

I. Product Overview

PR6426/010-140 is a 32mm eddy current sensor under the EPRO brand of Emerson. It is a core measurement component of the MMS6000 turbine monitoring system (TSI), used for non-contact measurement of parameters such as shaft vibration, shaft displacement, eccentricity, and oil film thickness of rotating machinery. It is suitable for key equipment such as steam turbines, gas turbines, compressors, and fans.

II. Model Meaning (PR6426/010-140)

PR6426: Serial Number (32mm probe, rectangular flange installation)

010: Cable Specification (without armor, length 1m)

140: Matching Calibration and Range Code

III. Core Technical Parameters

Measurement Performance

Static Range: ±4.0mm (linear range)

Sensitivity: 2V/mm (50.8mV/mil), error ≤ ±1.5%

Linear Error: ≤ ±1.5% (with CON021/CON041 preamplifier)

Frequency Response: 0~12kHz (-3dB)

Recommended Gap: 5.5mm (center position)

Environmental and Physical

Operating Temperature: -35℃ ~ +180℃; Short-term (＜4h) up to 200℃

Probe Tolerance: -40℃ ~ +150℃ (standard), up to +250℃ with high-temperature cable

Protection Grade: IP67 (fully sealed ceramic package)

Cable: Double-layer shielding (tin-plated copper mesh + aluminum foil), anti-electromagnetic interference (EN 61326)

Weight: Approximately 800g (including 1m unarmored cable)

Axial Diameter Requirement: ≥200mm

Electrical Compatibility

Matching Preamplifier: CON021/916-240, CON041, etc.

Output Signal: ±5V analog (corresponding to full scale)

Calibration: Factory calibration with 42CrMo4 steel, complete calibration set, no on-site calibration required

IV. Installation Requirements

Mechanical Installation

Method: Rectangular flange fixation, probe perpendicular to the measured shaft surface

Gap: Installation gap set at 5.5mm (corresponding to 0V output from the preamplifier)

Surface: Measured surface is ferromagnetic steel (42CrMo4), surface roughness Ra ≤ 3.2μm, no oil stains, rust

Spacing: Edge of the probe ≥ 5mm from the edge of the shaft, to avoid edge effect

Cable Installation

Path: Away from power cables (spacing > 300mm), avoid parallel wiring

Shielding: Single-point grounding (only on the preamplifier side), sensor side shield floating

Length: Standard 1m, can be equipped with extension cable (such as EXC0147), total length ≤ 10m

V. Wiring Definitions (Sensor → Preamplifier)

Core Wire 1: +24V (preamplifier power supply)

Core Wire 2: 0V (ground)

Core Wire 3: Signal Output

Shield Layer: Ground on the preamplifier side, floating on the sensor side

VI. Calibration and Debugging

Factory Calibration: Sensor and preamplifier complete calibration, linearity and sensitivity already calibrated, no secondary calibration required on-site. On-site commissioning

Power Supply: The preamplifier is connected to -24VDC (±10%)

Gap Adjustment: Slowly move the probe until the output of the preamplifier is 0V (corresponding to a 5.5mm gap), then lock the fixing bolt

Signal Check: When rotating the shaft, the output should change linearly with vibration/displacement, without drift or noise

VIII. Fault Troubleshooting

No signal output

Check if the power supply of the preamplifier (-24VDC) is normal

Verify the correctness of the wiring (positive and negative poles, signal, and shielding)

Measure the resistance of the probe: Normal value is approximately 100Ω, open circuit / short circuit indicates damage

Signal drift / instability

Excessive / insufficient gap: Re-adjust to 5.5mm

Incorrect shielding grounding: Change to single-point grounding (on the preamplifier side)

Environmental interference: Keep away from strong electromagnetic sources such as frequency converters and motors

Linear error exceeds tolerance

Material being measured does not match: Use a 42CrMo4 steel shaft surface

Probe contamination: Clean the oil stains and metal debris on the probe surface

IX. Accessories and Selection

Must be paired: PR6426/010-140 + CON021/916-240 (standard combination)

System integration: Connect the output to the MMS6000 series monitoring module (such as MMS6210, MMS6310), or DCS/DEH system